Mammals of the San Gabriel Mountains of California

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Title: Mammals of the San Gabriel Mountains of California
Author: Vaughan, Terry A.
Language: English
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[Transcriber's Note: The following changes have been made to the
original text:
Page 520: "Pinus Lambertiana" changed to "Pinus lambertiana"
Page 531: "Virginia Opossom" changed to "Virginia Opossum"
Page 551: "4600 ft. 3" changed to "4600 ft., 3"
Page 555: "laural sumac" changed to "laurel sumac"
Page 566: "concealed itelf" changed to "concealed itself"
Page 582: "Oakshott, G. B." changed to "Oakeshott, G. B."

Instances of inconsistent hyphenation have been preserved.

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page number a table was originally located.

The list of University of Kansas Publications was originally printed on
the front and back covers. For this version of the text, the list has
been combined and placed at the end of the text.]

UNIVERSITY OF KANSAS PUBLICATIONS
MUSEUM OF NATURAL HISTORY

Volume 7, No. 9, pp. 513-582, 4 pls., 1 fig. in text, 12 tables

November 15, 1954

Mammals of the San Gabriel Mountains
of California

BY
TERRY A. VAUGHAN

UNIVERSITY OF KANSAS
LAWRENCE
1954

UNIVERSITY OF KANSAS PUBLICATIONS
MUSEUM OF NATURAL HISTORY

Volume 7, No. 9, pp. 513-582, 4 pls., 1 fig. in text, 12 tables

November 15, 1954

Mammals of the San Gabriel Mountains
of California

BY
TERRY A. VAUGHAN

UNIVERSITY OF KANSAS
LAWRENCE
1954

UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, A. Byron Leonard,
Robert W. Wilson

Volume 7, No. 9, pp. 513-582, 4 pls., 1 fig. in text, 12 tables
Published November 15, 1954

UNIVERSITY OF KANSAS
LAWRENCE, KANSAS

PRINTED BY
FERD VOILAND, JR., STATE PRINTER
TOPEKA, KANSAS
1954

[Illustration]

25-5184

MAMMALS OF THE SAN GABRIEL MOUNTAINS OF CALIFORNIA

Terry A. Vaughan

CONTENTS

PAGE

INTRODUCTION 515

DESCRIPTION OF THE AREA 516

BIOTIC PROVINCES AND ECOLOGIC ASSOCIATIONS 518
Coastal Sage Scrub Association 521
Southern Oak Woodland Association 523
Chaparral Association 524
Yellow Pine Forest Association 526
Pinyon-juniper Woodland Association 527
Sagebrush Scrub Association 530
Joshua Tree Woodland Association 530

ACCOUNTS OF SPECIES 531

LITERATURE CITED 581

INTRODUCTION

This paper presents the results of a study of the mammals of the San
Gabriel Mountains of southern California, and supplements the more
extensive reports on the biota of the San Bernardino Mountains by
Grinnell (1908), on the fauna of the San Jacinto Range by Grinnell and
Swarth (1913), and on the biota of the Santa Ana Mountains by Pequegnat
(1951).

The primary objectives of my study were to determine the present
mammalian fauna of the San Gabriel Mountains, to ascertain the
geographic and ecologic range of each species, and to determine the
systematic status of the mammals. In addition, certain life history
observations have been recorded.

Field work was done in the north-south cross section of the mountains
from San Gabriel Canyon on the west, to Cajon Wash on the east; and from
the gently sloping alluvium at the Pacific base of the mountains at
roughly 1000 feet elevation on the south, over the crest of the range to
the border of the Mojave Desert at an elevation of 3500 feet on the
north. Camps were established at many points in the area with the object
of collecting the mammals of each association and each habitat. Field
work was begun in the San Gabriels in November 1948, and was carried
on intermittently until March 1952. I was unable to carry on field work
in any summer.

For advice and assistance in various ways I am grateful to Drs.
Willis E. Pequegnat, Walter P. Taylor, Henry S. Fitch, E.
Raymond Hall, Mr. Steven M. Jacobs and my wife, Hazel A.
Vaughan.

More than 350 mammals were prepared as study specimens; most of
these are in the University of Kansas Museum of Natural History.
Approximately a fifth of them are in the collection of the
Department of Zoology at Pomona College, and a few are in the
University of Illinois Museum of Natural History. No symbol is
used to designate specimens in the University of Kansas Museum
of Natural History. Specimens from the Department of Zoology of
Pomona College and the University of Illinois Museum of Natural
History are designated by PC and IM, respectively.

[Illustration: FIG. 1. Map of the San Gabriel Mountain area showing the
positions of places mentioned in the text.]

DESCRIPTION OF THE AREA

The San Gabriel Mountains are approximately sixty-six miles long, and
average twenty miles wide. The main axis of the range trends nearly east
and west, and extends from longitude 117°25' to longitude 118°30'. The
widest part of the range is bounded by latitude 34°7' and latitude
34°30'.

The San Gabriel Mountains connect the Sierra Nevada with the Peninsular
Ranges of southern California and Baja California. On the west the San
Gabriels are bordered by the Tehachapi Mountains, which stretch
northeastward to meet the southern Sierra Nevada; to the east, beyond
Cajon Pass, the San Bernardino Mountains extend eastward and then curve
southward to the broad San Gorgonio Pass, from which the San Jacinto
Range stretches southeastward to merge with the Peninsular Ranges.

The rocks comprising the major part of the San Gabriel Mountains
probably were intruded in Late Jurassic times, with severe metamorphic
activity taking place concurrently. A long period of erosion followed
after which deposition took place during much of the Tertiary.
Deformation and uplift beginning in Middle Miocene times resulted in the
formation of east-west-trending faults along both sides of the range. By
repeated movements along these faults the Late Jurassic crystalline
rocks were lifted above late Tertiary and Quaternary sediments and
elevated above the surrounding terrain. Continued uplifts in
post-Pleistocene time together with erosion in Recent times have shaped
the San Gabriel Mountains (Oakeshott, 1937).

The alluvial slopes at the coastal base of the range give way to the
foothills at roughly 1800 feet elevation; whereas the Mojave Desert
merges with the interior foothills at elevations near 4000 feet. The
crest or drainage-divide of the range varies from 6000 to 8000 feet in
elevation, and many peaks are more than 8000 feet high. San Antonio
Peak, the highest peak of the range, rises to an altitude of 10,080
feet. The mountains are characteristically steep and the slopes are
deeply carved by canyons, the larger of which have permanent streams.
The abruptness of the Pacific slope is in many places impressive. The
horizontal distance from the top of Cucamonga Peak, at an elevation of
8911 feet, to the base of the coastal foothills directly to the south,
at 2250 feet, an elevational difference of 6661 feet, is only 3.8 miles.
From the base of Evey Canyon, at 2250 feet, to an unnamed peak to the
northwest with an elevation of 5420 feet, the horizontal distance is 2.1
miles. Because of the steep, rocky nature of many of the slopes and the
lack of soil on them, vegetation may be sparse even at high elevations.
There are few meadows in the mountains.

Because the San Gabriels stand approximately thirty miles from the
Pacific Ocean and are a partial barrier to Pacific air masses sweeping
inland, the desert side and the coastal side of the range differ
climatically. The coastal slope receives much heavier precipitation than
the desert slope. The precipitation, for 1951, of 25.36 inches recorded
at the mouth of San Antonio Canyon on the Pacific slope contrasts with
7.17 inches recorded at Valyermo at the desert base. Nearly all of the
precipitation comes in winter. The higher parts of the range, above
approximately 5000 feet, receive much of their mid-winter precipitation
in the form of snow. Snow often extends down the desert slope well into
the Joshua Tree belt. When there are heavy winter rains the channels of
the usually dry washes are filled with rushing, turbid water. There are
striking differences in temperature between the two sides of the range
and between the lower elevations of the mountains and the higher parts.
For example, in December 1951, the mean temperature at the base of San
Antonio Canyon (2225 feet) at the coastal foot of the range was 55.4°F,
while at Llano (3764 feet) at the desert base it was 43.7°F. In this
same year the December mean for Table Mountain (7500 feet), on the
desert slope, was 33.4°F. The temperature means for July, 1951, at San
Antonio Canyon, Llano, and Table Mountain, were 77.3°F, 82.1°F, and
69.2°F respectively. The weather records for 1951 were used for
illustration because average temperature and average precipitation for
many other years are lacking for most of the weather stations in the
area. There is an important difference in the humidity on the two sides
of the range, but actual data are not available. At certain times,
especially in spring, fog banks moving in from the Pacific Ocean
frequently blanket the coastal base of the mountains and the foothills.
On such days the fog generally "burns off" in the morning, but may
persist into the afternoon or throughout the day. Never in my experience
has fog spilled over the main part of the range far onto the desert
slope, although the fog may push through the lower passes to be
dissipated quickly in the dry desert atmosphere. The obvious differences
in the biota on the two sides of the range are probably due to the
contrasting climates.

BIOTIC PROVINCES AND ECOLOGIC ASSOCIATIONS

Because of the elevational extremes and attendant climatic contrasts in
the San Gabriel Mountains, there is a rather wide range of environmental
conditions. Four life-zones are represented: Lower Sonoran, Upper
Sonoran, Transition, and Canadian. Within these zones certain ecologic
communities can be recognized; these represent several biotic
provinces. Table 1 shows the relationships between the environmental
categories recognized by the writer in the San Gabriel Mountains. The
biotic province and ecologic community system is that developed by Munz
and Keck (1949), and the life-zone system is that of Merriam (1898).

TABLE 1.--RELATIONS OF THE MAJOR ENVIRONMENTAL CATEGORIES OF THE SAN
GABRIEL MOUNTAINS.

The Californian Biotic Province dominates the biotic aspect of the
coastal slope of the range. Thirty-nine out of the seventy-two mammals
recorded from the San Gabriels are typical of this Province. The coastal
sage-flats at the Pacific base of the mountains and the vast tracts of
chaparral of the coastal slope are included in this Province.

Forming a hiatus between the Pacific and the desert slope is the Sierran
Biotic Province consisting of coniferous forests on the crest of the
range. The chipmunk (_Eutamias speciosus speciosus_) and the introduced
black bear (_Ursus americanus californiensis_) are the only two mammals
which can be considered typical of this area. On the higher peaks of the
range, such as Mount San Antonio and Mount Baden Powell, the Canadian
Life-zone is represented by certain boreal plants.

At scattered points along the crest of the range and on the desert
slope, the Nevadan Biotic Province is represented by the sagebrush scrub
association. No mammals can be considered typical of this region.

The Southern Desert Biotic Province occurs below 6000 feet elevation on
the interior slope of the range, and markedly influences the mammal
fauna of this slope. Twenty-one species of mammals are typical of this
Province.

SCIENTIFIC AND COMMON NAMES OF PLANTS MENTIONED IN THIS REPORT

_Pinus lambertiana_ Sugar Pine
_P. monophylla_ One-leaf Pinyon
_P. ponderosa_ Yellow Pine
_P. contorta_ Lodge-pole Pine
_Pseudotsuga macrocarpa_ Big-cone Spruce
_Abies concolor_ White Fir
_Libocedrus decurrens_ Incense-Cedar
_Juniperus californica_ Juniper
_Ephedra sp._ Desert-Tea
_Bromus sp._ Brome Grass
_Yucca Whipplei_ Spanish Bayonet
_Y. brevifolia_ Joshua Tree
_Salix sp._ Willow
_Alnus rhombifolia_ Alder
_Castanopsis sempervirens_ Chinquapin
_Quercus Kelloggii_ California Black Oak
_Q. agrifolia_ California Live Oak
_Q. dumosa_ Scrub Oak
_Eriogonum fasciculatum_ California Buckwheat
_Umbellularia californica_ Bay, California-laurel
_Ribes nevadense_ Gooseberry
_R. indecorum_ Currant
_R. Roezlii_ Currant
_Plantanus racemosa_ Sycamore
_Rubus vitifolius_ Western Blackberry
_Cercocarpus ledifolius_ Mountain Mahogany
_C. betuloides_ Mountain Mahogany
_Adenostoma fasciculatum_ Greasewood
_Purshia glandulosa_ Antelope-brush
_Prunus virginiana_ Choke Cherry
_P. ilicifolia_ Holly-leaved Cherry
_Larrea divaricata_ Creosote Bush
_Rhus diversiloba_ Poisonoak
_R. trilobata_ Squaw Bush
_R. laurina_ Laurel Sumac
_R. integrifolia_ Lemonadeberry
_R. ovata_ Sugarbush
_Rhamnus crocea_ Buckthorn
_Ceanothus sp._ Lilac
_C. cordulatus_ Snow-brush
_Fremontia californica_ California Slippery-elm
_Opuntia occidentalis_ Prickly-pear
_Arctostaphylos sp._ Manzanita
_Salvia mellifera_ Black Sage
_S. apiana_ White Sage
_Lycium Andersonii_ Box-thorn
_Haplopappus squarosus_
_Chrysothamnus nauseosus_ Rabbitbrush
_Baccharis sp._ Mule Fat
_Franseria dumosa_ Burroweed
_Artemisia tridentata_ Basin Sagebrush
_A. californica_ Coastal Sagebrush
_Lepidospartum squamatum_ Scale-broom
_L. latisquamatum_ Scale-broom
_Tetradymia spinosa_ Cotton-thorn

Coastal Sage Scrub Association

MAJOR PLANTS

_Artemisia californica_
_Salvia apiana_
_Salvia mellifera_
_Eriogonum fasciculatum_
_Rhus integrifolia_
_Opuntia occidentalis_
_Haploppapus squarrosus_

This association is restricted to the Pacific base of the range, is
typical on the alluvium at the bases of the coastal foothills, and
usually grades into the chaparral at about 1800 feet elevation. When
seen from above, the rather level terrain of the association is broken
sharply at the mouths of canyons by dry washes, and is limited below, to
the south, by cultivated land. The coastal sagebrush is the most
characteristic plant of this association, occurring in all undisturbed
parts of the area.

There are several habitats within the coastal sage scrub association.
These differ from one another chiefly on the basis of soil type. The
soil of the rather level sageland in most places is rocky or gravelly,
or, as adjacent to washes, it is finely sandy in texture, and supports
the major plants of the association. Most of the eroded adobe banks at
the bases of the foothills support these same plants, with white sage
being the dominant species. Locally, as in damp hollows or cleared
areas, there is grassland. Jumbles of boulders, sand, gravel, and steep
cutbanks, are characteristic of the channels of dry washes, these areas
supporting sparse vegetation. The fauna and flora of the washes are
distinct from those of surrounding sage flats. Because they are included
within the geographic limits of the coastal sage belt, however, the
washes are discussed along with this association.

The abruptness with which one habitat gives way to another in this
association causes sharp dividing lines between the local ranges of
certain mammals. For example, in trap lines transecting dry washes and
level sageland two assemblages of rodents were found. That part of the
line amid the boulders and cutbanks of the wash took mostly
_Peromyscus eremicus fraterculus_ and _Neotoma lepida intermedia_, while
_Perognathus fallax fallax_, _Dipodomys agilis agilis_, and _Peromyscus
maniculatus gambeli_ were taken in the adjacent sage flats. The steep
adobe slopes of the foothills, which constitute the upper part of the
coastal sage scrub association, are commonly inhabited by _Peromyscus
californicus insignis_, which rarely occurs in the level tracts of sage
a few yards away. Thus, this association is not homogeneous with regard
to its rodent population; many of these species have local and
discontinuous distributions.

The following list gives the results of about 500 trap nights (a trap
night equals one trap set out for one night) in typical coastal
sage-scrub association one-half mile southwest of the mouth of San
Antonio Canyon, at 1700 feet elevation.

TABLE 2.--YIELD OF 500 TRAP-NIGHTS IN THE COASTAL SAGE SCRUB
ASSOCIATION.

======================================================================
| Number | Per cent
| | of total
--------------------------------------------------+--------+----------
Perognathus fallax fallax | 31 | 30.7
Dipodomys agilis agilis | 20 | 19.8
Reithrodontomys megalotis longicaudus | 4 | 4.0
Peromyscus californicus insignis | 4 | 4.0
P. eremicus fraterculus | 7 | 6.9
P. maniculatus gambeli | 20 | 19.8
Neotoma lepida intermedia | 9 | 8.8
N. fuscipes macrotis | 2 | 2.0
Microtus californicus sanctidiegi | 4 | 4.0
--------------------------------------------------+--------+----------

The list below indicates the catch in 200 trap nights in San Antonio
Wash, at 1700 feet elevation and within the realm of the coastal sage;
all of the traps were set in rocky and sandy main channels of the wash.

TABLE 3.--YIELD OF 200 TRAP-NIGHTS IN SAN ANTONIO WASH.

======================================================================
| Number | Per cent
| | of total
--------------------------------------------------+--------+----------
Perognathus fallax fallax | 2 | 5.1
Peromyscus californicus insignis | 2 | 5.1
P. eremicus fraterculus | 26 | 66.7
Neotoma lepida intermedia | 9 | 23.1
--------------------------------------------------+--------+----------

The prickly-pear cactus is of obvious importance to certain mammals of
the coastal sage belt. This cactus is most common in disturbed areas
such as sandy flats bordering washes, eroded adobe banks, and land once
cleared by man. In these areas it is often the dominant plant with
respect to area covered, usually growing in dense patches each covering
approximately 150 square feet. It provides substitute nesting sites for
_Neotoma lepida_ in areas devoid of rock piles, and is probably the
major factor governing the distribution of this wood rat in the
sageland. Cottontails and brush rabbits use prickly-pear cactus
extensively as refuge. Their forms and short burrows can be seen beneath
many of the clumps of cactus.

This cactus serves as food for many mammals at least in the fruiting
period in the fall. Usually only the fruit is eaten, but some pads are
chewed by rabbits. The fruit or seeds of this plant are eaten by striped
skunks, gray foxes, coyotes, pocket mice, kangaroo rats, wood rats, and
probably white-footed mice.

The coyote is the dominant carnivore of the coastal sage flats. Many
individuals spend the day in the adjacent chaparral-covered foothills
and travel down into the flats at night to forage.

Southern Oak Woodland Association

MAJOR PLANTS

_Alnus rhombifolia_
_Quercus agrifolia_
_Ribes indecorum_
_Rhus integrifolia_
_Rhus ovata_
_Rhus trilobata_

This association is limited to the Pacific slope of the mountain range,
occurs in the mouths of canyons and on the floors of canyons, and
extends up the larger canyons to 4000 feet elevation or higher. In a few
areas on the flats at the coastal base of the range the oaks replace the
coastal sage.

The large oaks forming an overhead canopy and the lack of much
undergrowth give the oak woodland a shaded parklike appearance. Few
brushy or herbaceous plants grow in the mull-laden soil beneath the
oaks. Some grasses, however, are present locally.

Two habitats are found in the oak woodland: the pure oak woodland and
the riparian. Much of the oak woodland is in canyons and therefore near
streams or seepages. The larger streams have bordering growths of
alders, willows, and blackberries, inhabited by meadow mice and shrews
that are normally absent from the adjacent oak woodland. NEOTOMA
FUSCIPES MACROTIS and PEROMYSCUS CALIFORNICUS INSIGNIS are commonly
found in the riparian habitat, and _Peromyscus boylii_ probably reaches
peak abundance in the stream-side thickets and tangles of plant debris.

The rather open floor of the oak woodland is relatively devoid of mammal
life. _Peromyscus californicus_ and _Peromyscus boylii_, the only
ground-dwelling rodents commonly found here, usually are taken near the
limited areas of brushy growth, or the shelter afforded by logs and
fallen branches. The paucity of shelter for small mammals seems to be an
important factor limiting rodent populations in the oak woodland.

In the foothills of the San Gabriels the gray squirrel is restricted to
the oak woodland, even though this association may be represented by
only a narrow strip of canyon bottom oak trees. The presence or absence
of "bridges" of oak woodland between mountains which are centers of gray
squirrel populations and nearby ranges has probably been a major factor
influencing the present geographic distribution of this animal.

The raccoon is the most abundant carnivore of the oak woodland, being
especially common in the riparian habitat.

Chaparral Association

MAJOR PLANTS

_Adenostoma fasciculatum_
_Rhamnus crocea_
_Quercus dumosa_
_Cercocarpus betuloides_
_Yucca Whipplei_
_Prunus ilicifolia_
_Ceanothus sp._
_Arctostaphylos sp._
_Umbellularia californica_

This association is characteristic of the Pacific slope of the San
Gabriels and extends from roughly 2000 feet elevation to 5000 or 6000
feet elevation. The ecotone between the chaparral and yellow pine forest
associations covers a broad elevational belt, with chaparral following
dry slopes up into coniferous forests, and conifers extending down north
slopes surrounded by chaparral.

The chaparral association is characterized by tracts of dense brushy
plants. These plants are from three to ten feet tall, their interlacing
branches often forming nearly impenetrable thickets. Typically little
herbaceous growth is present beneath the chaparral, the ground being
covered with varying amounts of mull.

The effects of fire, slope, exposure, and elevation, make the chaparral
association extremely varied with regard to habitats or plant
formations. There are nearly pure stands of greasewood on the lower arid
slopes; scrub oak, sumac, and lilac clothe less dry exposures; scrub
oak and bay trees occur commonly amid granite talus; and locally groves
of bigcone-spruce are found. Because of the many habitats present, and
the difficulty of collecting in the chaparral, less was learned of the
ecology of the mammals in this association than of those occurring
elsewhere. The distribution of several chaparral-inhabiting mammals
seems to be influenced by the distribution of locally characteristic
plants, for example oak and bay woodland, or greasewood chaparral.

Several habitats within the chaparral community support few species of
mammals and few individuals. Possibly the compact, rocky nature of the
soil limits burrowing rodents, and the lack of herbaceous growth limits
the food supply. Steep rocky slopes in San Antonio Canyon grown to
mountain-mahogany and scrub oak were sparsely populated by _Peromyscus
boylii rowleyi_, _Peromyscus californicus insignis_, and _Neotoma
fuscipes macrotis_. Fifty traps set on such a slope for one night caught
only three _Peromyscus_. Traps set in tracts of greasewood brush on dry
south slopes at the head of Cow Canyon produced only California mice,
_Peromyscus californicus insignis_ Rhoads.

Following is a list of the mammals taken in the course of approximately
600 trap nights in the lower parts of the chaparral belt. All of the
traps were set on slopes in San Antonio Canyon below 4000 feet
elevation. The list gives a general indication of the relative numbers
of rodents inhabiting one chaparral habitat: the arid greasewood-covered
south slopes of the lower chaparral belt.

TABLE 4.--YIELD OF 600 TRAP-NIGHTS IN GREASEWOOD CHAPARRAL.

======================================================================
| Number | Per cent
| | of total
--------------------------------------------------+--------+----------
Perognathus californicus dispar | 4 | 10.0
Dipodomys agilis agilis | 4 | 10.0
Peromyscus californicus insignis | 25 | 62.5
Neotoma fuscipes macrotis | 7 | 17.5
--------------------------------------------------+--------+----------

Heteromyids are evidently absent from the upper parts of the chaparral
association, but cricetid rodents are common there beneath heavy clumps
of lilac and in the talus beneath oaks and bay trees. The following list
gives the mammals taken in the course of about 200 trap nights in the
granite talus one half mile northwest of the mouth of Icehouse Canyon,
at 5200 feet elevation.

TABLE 5.--YIELD OF 200 TRAP-NIGHTS IN THE UPPER PART OF THE CHAPARRAL
ASSOCIATION.

======================================================================
| Number | Per cent
| | of total
--------------------------------------------------+--------+----------
Eutamias merriami merriami | 3 | 6.3
Peromyscus boylii rowleyi | 38 | 79.2
Neotoma lepida intermedia | 2 | 4.2
Neotoma fuscipes macrotis | 5 | 10.4
--------------------------------------------------+--------+----------

The gray fox is the dominant carnivore of the chaparral association and
forages widely in all habitats.

Yellow Pine Forest Association

MAJOR PLANTS

_Pinus ponderosa_
_P. lambertiana_
_Libocedrus decurrens_
_Abies concolor_
_Quercus Kelloggii_
_Ribes nevadense_
_Ribes Roezlii_
_Arctostaphylos sp._
_Ceanothus cordulatus_

The crest of the range, from the upper limit of the chaparral
association at roughly 6000 feet to the limited areas of boreal flora
above 8500 feet elevation, is covered by yellow pine forests. On the
desert slope of the range the coniferous forests which extend down to
about 6000 feet represent the best development of this association,
while the coniferous forests on the coastal side of the drainage divide
are often more or less diluted by chaparral elements. For example,
yellow pines on the Pacific face of Blue Ridge at 7000 feet elevation
often grow in association with scrub oak and mountain-mahogany.

Few mammals are resident in the typical yellow pine forest as
characterized by dense coniferous timber and little herbaceous or brushy
growth. Here most of the species recorded actually find optimal
conditions in an adjacent habitat. The forest probably harbors surplus
individuals from adjacent preferred habitats, or, as in the case of
chipmunks and ground squirrels, the forest often serves as forage ground
while nearby brushy areas are utilized for breeding and shelter. The
abundance of birds in the timber contrasts strikingly with the paucity
of mammals there. The lack of a seed-producing understory, and the open
duff-covered stretches of ground on which rodents would be extremely
vulnerable to predation, probably in part account for the scarcity of
rodents.

Within the general area encompassed by the yellow pine forest there are
two major habitats, namely coniferous forest and chaparral. The
species of plants comprising the chaparral of the Transition Life-zone
are different from those comprising the chaparral of the Upper Sonoran
Life-zone on the Pacific slope. In the chaparral of the Transition
Life-zone, basin sagebrush and snowbrush grow in extensive patches in
clearings in the timber. Dense thickets of choke cherry cover many damp
hollows, and these thickets harbor the houses of _Neotoma fuscipes_. The
food and shelter afforded by these chaparral areas importantly influence
the local distribution of rodents: for example, _Dipodomys agilis_ and
_Perognathus californicus_ in the yellow pine area are found only in
association with chaparral, being completely absent from wooded areas.

The severe winter weather in this association must force many of the
mammals into periods of inactivity. Probably during the long periods in
the winter when snow covers the ground the heteromyids and sciurids
remain below ground.

Pinyon-Juniper Woodland Association

MAJOR PLANTS

_Pinus monophylla_
_Juniperus californica_
_Quercus dumosa var. turbinella_
_Purshia glandulosa_
_Fremontia californica_
_Cercocarpus ledifolius_
_Yucca Whipplei_

In the San Gabriel Mountains this association is limited to the desert
slope and reaches its lower limit at the bases of the foothills and
extends up to the lower edge of the yellow pine forests. The altitudinal
extent of the pinyon-juniper association is from roughly 4000 to 6000
feet elevation.

Several habitats are evident within the pinyon-juniper belt. On north
slopes in the upper part of this association, scattered stands of pinyon
pines are found with dense patches of scrub oak intervening, while on
other such slopes a dense chaparral is present, consisting primarily of
scrub oak, mountain-mahogany, and California slippery-elm. In this type
of chaparral several hundred trap nights yielded only two rodent
species: _Neotoma fuscipes simplex_ and _Peromyscus truei montipinoris_.
There are few pinyons on the south slopes, especially in the lower parts
of the association; many of these slopes are clothed with an open growth
of manzanita and yucca, while northern exposures there support mostly
scrub oak. Many of the flats of the pinyon belt are grown to basin
sagebrush.

Following is a list of the mammals taken in about 400 trap nights at one
locality in the pinyon-juniper association. The area supported a mixed
growth of pinyon, scrub oak, mountain-mahogany, and antelope-brush,
together with smaller brushy plants, and was at the head of Grandview
Canyon, at an altitude of roughly 5000 feet.

TABLE 6.--YIELD OF 400 TRAP-NIGHTS IN THE PINYON-JUNIPER ASSOCIATION.

=====================================================================
| Number | Per cent
| | of total
-------------------------------------------------+--------+----------
Perognathus fallax pallidus | 3 | 11.5
Dipodomys agilis fuscus | 9 | 34.6
Peromyscus truei montipinoris | 10 | 38.5
Neotoma fuscipes simplex | 4 | 15.4
-------------------------------------------------+--------+----------

Although Munz and Keck (1949:101) considered the pinyon-juniper belt as
one association, on the desert slope of the San Gabriels pinyons and
junipers do not generally grow on common ground; but rather the juniper
belt represents a well defined habitat occurring between the pinyon
covered slopes and the flats that support Joshua trees. Because the
mammalian populations of the pinyon belt and the juniper belt are
somewhat different, the mammals of these areas are most conveniently
taken up separately.

In the juniper belt the juniper tree is of marked ecologic significance;
the distribution of _Peromyscus truei_ and _Neotoma fuscipes_ is
determined here by the presence of junipers. At certain times of year
the fruit of this plant is eaten by coyotes, kangaroo rats, and wood
rats.

The list below indicates the results of approximately 500 trap nights in
the juniper belt near Mescal Canyon, between 4000 and 5000 feet
elevation.

TABLE 7.--YIELD OF 500 TRAP-NIGHTS IN THE JUNIPER BELT.

======================================================================
| Number | Per cent
| | of total
--------------------------------------------------+--------+----------
Perognathus fallax pallidus | 16 | 16.7
Dipodomys merriami merriami | 3 | 3.1
Dipodomys panamintinus mohavensis | 36 | 37.5
Peromyscus truei montipinoris | 22 | 22.9
Peromyscus maniculatus sonoriensis | 12 | 12.5
Neotoma lepida lepida | 2 | 2.1
Neotoma fuscipes simplex | 2 | 2.1
Onychomys torridus pulcher | 3 | 3.1
--------------------------------------------------+--------+----------

PLATE 1

[Illustration: FIG. 1. View of typical coastal sage scrub association,
showing in foreground white sage, and coastal sagebrush. The adobe banks
beyond are grown mainly to white sage. Small mammals are abundant in
this association, with _Dipodomys agilis_, _Perognathus fallax_, and
_Sylvilagus audubonii_ being characteristic of the area. Photo March 25,
1952, at mouth of San Antonio Canyon, 1800 feet elevation.]

[Illustration: FIG. 2. View of a main channel in San Antonio Wash on
Pacific slope. The wash is a distinct habitat in the coastal sage scrub
association, and is the preferred habitat of _Peromyscus eremicus
fraterculus_ and _Neotoma lepida intermedia_. These rodents find shelter
in the piles of boulders. Photo February 2, 1952, in San Antonio Wash,
at 1700 feet elevation.]

PLATE 2

[Illustration: FIG. 1. Southern oak woodland association. The open
leaf-strewn floor of the woodland lacks shelter for ground-dwelling
rodents and the population of rodents is small. _Peromyscus boylii
rowleyi_ is the commonest rodent. Photo March 10, 1952, in Evey Canyon,
2700 feet elevation.]

[Illustration: FIG. 2. Yellow pine forest association, composed largely
of yellow pines, white fir, and black oak. Photo April 27, 1952, at Big
Pines, 6800 ft. elevation.]

PLATE 3

[Illustration: FIG. 1. View of the sagebrush scrub association showing a
nearly pure stand of basin sagebrush. _Dipodomys agilis perplexus_ and
_Reithrodontomys megalotis longicaudus_ occur in this association, and
_Peromyscus truei montipinoris_ is present where this association merges
with the pinyon-juniper association. Photo April 27, 1952, in Swarthout
Valley, 6200 feet elevation.]

[Illustration: FIG. 2. View of a pinyon pine woodland. This habitat
constitutes the upper part of the pinyon-juniper association, and is the
habitat of _Neotoma fuscipes simplex_, _Peromyscus truei montipinoris_,
and _Eutamias merriami merriami_. Photo April 27, 1952, in Sheep Creek
Canyon, 5500 feet elevation.]

PLATE 4

[Illustration: FIG. 1. View of the juniper belt. This habitat forms the
lower part of the pinyon-juniper association. _Perognathus fallax
pallidus_, _Dipodomys panamintinus mohavensis_, and _Peromyscus truei
montipinoris_ are typical of this area. Photo April 27, 1952, at Desert
Springs, 4300 feet elevation.]

[Illustration: FIG. 2. Joshua tree woodland association. The
characteristic mammals are _Dipodomys panamintinus mohavensis_, _D.
merriami merriami_, and _Onychomys torridus pulcher_. Photo January 4,
1952, 6 miles east and 2 miles south Llano, 3600 feet elevation.]

The biota of the washes that cut through the juniper belt in and below
many of the larger canyons differs from that of the surrounding
juniper-clad benches. Because the washes are in the same geographic area
as the juniper belt they are discussed together. These washes on desert
slopes are densely populated by rodents derived from adjacent areas, and
support vegetation typical of higher floral belts in association with
xerophytic, typically desert, species. In a sense, the washes serve to
mix up the mammals of adjacent areas. For example, _Onychomys torridus
pulcher_ and _Peromyscus eremicus eremicus_, which are mammals typical
of the desert, were found in Mescal Wash above their usual desert range;
and _Peromyscus californicus insignis_ and _Peromyscus boylii rowleyi_,
which are chaparral inhabiting mammals, were found in the wash far
removed from their chaparral environment. Washes are evidently effective
agents in facilitating the dispersal of certain species of mammals. It
is easy to envision a species crossing hostile habitats _via_ dry washes
to invade suitable niches in an area which is geographically and
ecologically isolated from the original home of the species.
Approximately 500 trap nights in Mescal Wash, at 4100 feet elevation, in
the lower edge of the juniper belt, yielded the following mammals:

TABLE 8.--YIELD OF 500 TRAP-NIGHTS IN MESCAL WASH (DESERT SLOPE).

==========================================================
| Number | Per cent
| | of total
--------------------------------------+--------+----------
Perognathus fallax pallidus | 5 | 4.5
Dipodomys panamintinus mohavensis | 43 | 38.7
Peromyscus californicus insignis | 3 | 2.7
Peromyscus truei montipinoris | 1 | .9
Peromyscus boylii rowleyi | 2 | 1.8
Peromyscus eremicus eremicus | 28 | 25.0
Peromyscus maniculatus sonoriensis | 23 | 20.5
Onychomys torridus pulcher | 4 | 3.5
Neotoma lepida lepida | 3 | 2.7
--------------------------------------+--------+----------

_Dipodomys panamintinus mohavensis_, _Neotoma fuscipes simplex_, and
_Peromyscus truei montipinoris_ are probably the most characteristic
mammals of the pinyon-juniper association.

Sagebrush Scrub Association

MAJOR PLANTS

_Bromus sp._
_Artemisia tridentata_
_Chrysothamnus nauseosus_
_Purshia glandulosa_

This association is found on only the crest and desert slope of the
range between 5000 and 8000 feet elevation. There it characteristically
occupies flats and clearings in the yellow pine forest and
pinyon-juniper woodland. The dominant plant of the association is basin
sagebrush, and in many places this plant forms mixed growths with
snowbrush and _Haplopappus_. The low brush of this association is formed
by closely spaced bushes with grasses growing between.

Because of its limited occurrence in the San Gabriel Mountains, this
association there has relatively little effect on mammalian
distribution. Locally, nevertheless, the presence of this association
governs the distribution of certain mammals. For example, on Blue Ridge,
islands of sagebrush amid the conifers provide suitable habitat for
_Dipodomys agilis perplexus_ and _Perognathus californicus bernardinus_;
and in Swarthout Valley _D. a. perplexus_, _Reithrodontomys megalotis
longicaudus_, and _Lepus californicus deserticola_ are seemingly
restricted to the sagebrush flats.

Joshua Tree Woodland Association

MAJOR PLANTS

_Yucca brevifolia_
_Lycium Andersonii_
_Eriogonum fasciculatum_
_Tetradymia spinosa_
_Ephedra sp._
_Larrea divaricata_

This association is on the piedmont that dips toward the Mojave Desert
from the interior base of the San Gabriels. The widely spaced Joshua
trees with low bushes between, and the dry washes breaking the level
terrain below the mouths of canyons are typical of this area. Field work
was extended no farther down into the desert than about the 3500 foot
level, where this association was still dominant.

Although the vegetation of this area is scattered and sparse, presenting
a barren and sterile aspect, the area supports a rather high population
of rodents. The soil at the bases of many large box-thorn- and
creosote-bushes is perforated by burrow systems of _Dipodomys
panamintinus_ or _Dipodomys merriami_, and those burrows abandoned by
kangaroo rats are used as retreats by _Onychomys torridus_ and
_Peromyscus maniculatus_. The mammals of this association are all
characteristic of the fauna of the Mojave Desert, with the ranges of
such species as the coyote and jack rabbit extending well up the desert
slope of the mountains.

The mammals listed below were taken in 1948 in roughly 400 trap nights
in the Joshua belt, at an elevation of 3500 feet, one mile below the
mouth of Graham Canyon.

TABLE 9.--YIELD OF 400 TRAP-NIGHTS IN THE JOSHUA TREE BELT.

======================================================
| Number | Per cent
| | of total
-----------------------------------+--------+---------
Dipodomys panamintinus mohavensis | 36 | 59.0
Dipodomys merriami merriami | 15 | 24.6
Onychomys torridus pulcher | 4 | 6.6
Peromyscus maniculatus gambeli | 6 | 9.8
-----------------------------------+--------+---------

Populations of _Dipodomys merriami_ and _D. panamintinus_ fluctuate
widely, possibly in response to weather cycles. In November of 1948
trapping in the Joshua belt showed that _panamintinus_ outnumbered
_merriami_ approximately three to one, whereas in December of 1951,
after a succession of unusually dry years, _merriami_ was the more
numerous. Further, _merriami_ occurred in the lower parts of the juniper
belt in 1951 where in 1948 it seemed to be absent.

_Dipodomys merriami merriami_ and _Onychomys torridus pulcher_ are
diagnostic of the Joshua tree woodland association in the San Gabriel
Mountains area, since few individuals of either species occur outside of
this association.

ACCOUNTS OF SPECIES

Family DIDELPHIDAE

=Didelphis marsupialis virginiana= Kerr

Virginia Opossum

The opossum is common in and near small towns and cultivated areas at
the Pacific base of the mountain range and does not thrive away from
human habitation; extensive trapping in the coastal sage and chaparral
belts produced no specimens except immediately adjacent to citrus
groves. Pequegnat (1951:47) mentions that opossums in the Santa Ana
Mountains of southern California are in the lower parts of the larger
canyons, especially near human habitation.

_Specimens examined._--Los Angeles County: Claremont, 1600 ft.,
2 (PC).

Family TALPIDAE

=Scapanus latimanus occultus= Grinnell and Swarth

California Mole

Workings of moles were found on the Pacific slope of the mountains from
1600 feet at Claremont up to 7500 feet on Blue Ridge, and on the Pacific
slope beneath basin sagebrush in Cajon Canyon one mile from desert slope
Joshua-tree flats, but not on the desert slope, although moles probably
occur on that slope in some of the places where there is suitable
habitat.

Near Camp Baldy in the sandy soil beneath groves of alders moles seemed
to be especially abundant. Although common on the coastal face of the
range, moles shunned compact, dry, or rocky soils. In the greasewood
chaparral one-half mile west of the mouth of Palmer Canyon, where the
soil was hard and rocky, mole tunnels were in soft soil that had
accumulated at the edge of a fire road beneath a steep road cut. The
assumption is that this accumulation contained insects attractive, as
food, to the moles.

_Specimens examined_, 2: Los Angeles County: Camp Baldy, 4200
ft., 1(PC); Claremont, 1600 ft., 1(PC).

Family SORICIDAE

=Sorex obscurus parvidens= Jackson

Dusky Shrew

Jackson (1928:124) recorded a specimen from Camp Baldy, 4200 feet, San
Antonio Canyon.

=Sorex ornatus ornatus= Merriam

Ornate Shrew

Both of my specimens were taken amid riparian growth on the Pacific
slope of the range.

_Specimens examined_, 2: Los Angeles County: San Antonio Canyon,
3500 ft., 1; Cobal Canyon, 5 mi. N Claremont, 1800 ft., 1 (PC).

=Notiosorex crawfordi crawfordi= (Coues)

Gray Shrew

One was taken in 1946 beneath a woodpile on the campus of Norton School,
two miles northeast of Claremont, and examined by Dr. W. E. Pequegnat.

Family VESPERTILIONIDAE

=Myotis yumanensis sociabilis= H. W. Grinnell

Yuma Myotis

A female was taken in lower San Antonio Canyon, 2800 feet elevation, on
September 27, 1951.

=Myotis evotis evotis= (J. A. Allen)

Long-eared Myotis

This species was observed and collected at several stations ranging from
2800 feet elevation in San Antonio Canyon, to Blue Ridge at 8200 feet,
and down the desert slope to 6000 feet at Jackson Lake. This
distribution encompasses most of the chaparral and yellow pine forest
associations. Within these areas, however, this bat shows marked habitat
preferences.

Woodland habitats seem to be preferred by _evotis_. At several ponds in
lower San Antonio Canyon this bat was observed repeatedly as it foraged
over the water and coursed low between rows of alders and _Baccharis_.
At Blue Ridge in September, 1951, these bats foraged approximately six
feet above the ground beneath the canopy of coniferous foliage and
between the trunks of the trees.

Most of the bats were taken by stretching fine wires above the surface
of a pond as outlined by Borell (1937:478). Collecting was generally
carried on until at least 11:00 p. m., and the time at which each bat
was taken at the pond was recorded, thereby making possible a rough
estimate of the pre-midnight forage period of each bat commonly
collected at the ponds. Usually bats taken at the start of their
supposed forage period had empty or nearly empty stomachs, whereas those
taken towards the end of their forage period had full or nearly full
stomachs. _M. evotis_ usually first appeared just at dark, well after
the pipistrelles and California myotis had begun foraging. The forage
period of _evotis_ seemed to begin approximately 30 minutes after sunset
and to end approximately two and one-quarter hours later.

Individuals of this species were taken from May 4, to October 14, 1951.
A female taken on May 19, 1951, in San Antonio Canyon, carried one
minute embryo, and one taken in the same locality on June 8, had one
embryo four millimeters in length.

_Specimens examined._--Total, 12, distributed as follows: Los
Angeles County: San Antonio Canyon, 2800 ft., 11; Claremont,
1100 ft., 1 (P.C.).

=Myotis volans interior= Miller

Interior Long-legged Bat

Although seldom found to be plentiful, this bat was recorded from many
points on both the coastal and desert slopes of the mountains. Specimens
were taken in the chaparral association in San Antonio Canyon, near
Jackson Lake among yellow pines, and in Mescal Canyon at the upper limit
of the Joshua tree woodland. Bats, probably _volans_, were noted over
sage flats at 8000 feet elevation on Blue Ridge. The only place where
these bats appeared to be numerous was Jackson Lake on the interior
slope; there, on September 19, 1951, _volans_ appeared with the
pipistrelles, and was the most common bat before dark.

An individual of this species taken on October 28, 1951, in a short
mine-shaft in the pinyon belt at the head of Grandview Canyon was slow
in its movements and felt as cold as the walls of the tunnel. It was
late afternoon and the temperature outside the cave was below 40°F. The
floor of the tunnel was covered with the hind wings of large moths of
the genus _Catocala_; _volans_ probably hung in the cave while eating
them.

The series of _volans_ from the San Gabriels shows that the two color
phases of this bat both occur in the area. Two specimens from Jackson
Lake contrast sharply with the rest of the series in their dark
coloration. Benson (1949:50) states that color variation in a series of
_volans_ from a given locality may be striking.

This bat was collected in San Antonio Canyon from 50 minutes after
sundown to two hours and 40 minutes after sundown. In this area these
bats did not visit the ponds in large numbers as they seemed to do on
the desert slope.

A female taken on May 29, 1951, contained one embryo nearly at term.

_Specimens examined._--Total, 9, distributed as follows: Los
Angeles County: Mescal Canyon, 8 mi. E and 5 mi. S Llano, 4900
ft., 1; 3 mi. W Big Pines, Swarthout Valley, 6000 ft., 3; San
Antonio Canyon, 2800 ft., 5.

=Myotis californicus californicus= (Audubon and Bachman)

California Myotis

On the Pacific face of the mountain range this bat was recorded commonly
below approximately 5000 feet elevation, where it seemed to be most
common in the oak woodland of canyons. On the desert slope it was
collected at Jackson Lake in yellow pine woodland, in Mescal Canyon in
the juniper belt, and bats presumably of this species were observed at
several points in the pinyon-juniper woodland.

Individuals of this species were often observed foraging from five to
ten feet above the ground around the alders and _Baccharis_ near San
Antonio Creek, but they did not fly so low or so near the vegetation as
did _Myotis evotis_. Here they were taken from 18 minutes to 55 minutes
after sunset; this indicates an early and short forage period.

This bat may be active even in winter. On February 8, 1952, in lower San
Antonio Canyon, a bat, probably of this species, was noted foraging; and
collecting in early November, 1951, yielded specimens.

On May 22, 1951, a female obtained in San Antonio Canyon had one
five-millimeter embryo, and subsequently all the females examined had
embryos until June 12, when collecting was discontinued.

_Specimens examined._--Total, 16, distributed as follows: Los
Angeles County: Mescal Canyon, 4800 ft., 2; Jackson Lake, 6000
ft., 1 (PC); San Antonio Canyon, 3900 ft., 1; San Antonio
Canyon, 2800 ft., 12.

=Pipistrellus hesperus merriami= (Dobson)

Western Pipistrelle

This is the most obvious if not the most common bat of the lower coastal
slopes of the San Gabriels. In the spring and fall of 1951 individuals
were noted from 1700 feet in the coastal sage scrub association to the
white fir forests on Blue Ridge at 8200 feet elevation and were
commonest in the rocky canyons of the lower Pacific slope below 4000
feet, and usually foraged near the steep canyon sides high above the
canyon bottoms.

Pipistrelles were generally the first bats to appear in the evening,
although the times of their appearance were irregular. In April and May,
in lower San Antonio Canyon, they appeared from 28 minutes before sunset
to 30 minutes after sunset, with the average time of appearance eight
and one-half minutes after sunset. Like _Myotis californicus_ this
pipistrelle seemed to have a short and early foraging period. No
pipistrelles were recorded at ponds later than one hour and five minutes
after sunset, and usually they were not seen later than 40 minutes after
sunset. Most of the specimens taken later than one half hour after
sunset had full stomachs. More than 50 pipistrelles were captured at the
ponds in San Antonio Canyon; six were kept for specimens. This species
is probably present in the area throughout the winter. Pipistrelles were
active in early April in Evey Canyon, were observed in early November
in San Antonio Canyon, and on January 26, 1952, an individual was noted
foraging near the mouth of Palmer Canyon. They are probably not active
in winter on the colder desert slope of the mountains.

Pipistrelles often foraged in loose flocks of about half a dozen
individuals. On many occasions these groups were first seen foraging
high up above the canyon bottom, then, as it grew darker, they descended
and foraged within 50 or 100 feet of the floor of the canyon.
Immediately before dark these groups seemed to have forage beats; one
minute several pipistrelles would be overhead, and the next minute none
would be in sight.

A female taken in San Antonio Canyon on June 8, 1951, contained two
five-millimeter embryos.

_Specimens examined._--Total, 6, distributed as follows: Los
Angeles County: San Antonio Canyon, 2800 ft., 5; Evey Canyon,
2400 ft., 1.

=Pipistrellus hesperus hesperus= (H. Allen)

Western Pipistrelle

This species was common in the spring and autumn of 1951 from the lower
edge of the yellow pine forest down into the belt of Joshua trees. In
early April on the desert slope at 4800 feet in Mescal Canyon,
pipistrelles foraged on evenings when it was windy but not cold. On cold
evenings (when the temperature was below roughly 45°F) none was seen. On
windy nights the pipistrelles often forsook their usual high forage
habits and foraged 15 feet or so above the ground where the vegetation
and outcrops of rock broke the force of the wind. In 1951 no
pipistrelles were noted on the desert slope later than October 15.

_Specimens examined._--Los Angeles County: Mescal Canyon, 4800
ft., 4.

=Eptesicus fuscus bernardinus= Rhoads

Big Brown Bat

This bat was on the coastal slope from the sage scrub association at
1100 feet, up to 8000 feet on Blue Ridge, and on the desert slope down
to the upper edge of the Joshua tree belt at 4800 feet in Mescal Canyon.
It was the most common bat at the ponds in San Antonio Canyon in May and
June of 1951, but in September and October of the same year none was
obtained there.

On the Pacific slope of the San Gabriels the big brown bats segregate
according to sex in the spring, the males occupying the foothills and
mountains and the females the level valley floor at the coastal base
of the range. Of 70 big brown bats captured in May and June of 1951, at
the ponds in San Antonio Canyon, only one was a female. A large colony
of more than 200 individuals in a barn near Covina, in the citrus belt,
was composed of only females.

Times of capture of this bat at the ponds in San Antonio Canyon ranged
from ten minutes after sunset to two hours and thirty minutes after
sunset. Generally these bats came to the ponds in groups of several
individuals, and often more than a dozen were captured in the course of
an evening's collecting.

_Specimens examined._--Total, 7, distributed as follows: Los
Angeles County: Mescal Canyon, 4800 ft., 1; San Antonio Canyon,
2800 ft., 2; Covina, 1100 ft., 4 (2PC).

=Lasiurus borealis teleotis= (H. Allen)

Red Bat

One female was taken on September 30, 1951, in San Antonio Canyon, at
2800 feet elevation. The descriptions which the citrus growers of the
Claremont and Glendora vicinity give of the bats they find occasionally
hanging in their citrus trees accurately describe this species. Its
seasonal occurrence there is unknown.

=Lasiurus cinereus cinereus= (Pasilot de Beauvois)

Hoary Bat

Specimens were collected in spring in 1951 at elevations of 2800 and
3200 feet in San Antonio Canyon, on the coastal slope, and in Mescal
Canyon at 4900 feet, on the desert slope. Large, fast flying bats,
probably of this species, were seen at Jackson Lake, 6000 feet
elevation, on October 15, 1951.

Hoary bats are present in the San Gabriels in the fall, winter, and
spring. In 1951 the last spring specimen was taken on June 11, in Mescal
Canyon; then collecting was discontinued until late September when the
first hoary bat was taken on the thirtieth of that month. From this date
on into the winter hoary bats were recorded regularly. They seemed to be
as common in early June as in most of April and May; possibly some
remain in the San Gabriels throughout the summer.

In spring these bats seem to segregate by sex; of twelve kept as
specimens and at least an equal number captured and released only one
was a female. All were captured above 2800 feet.

Hoary bats seem to have a long pre-midnight forage period, having been
captured at ponds from 21 minutes after sunset, to three hours and 26
minutes after sunset. Generally those taken early had empty stomachs
and those taken later had full stomachs. On the night of May 24, 1951, a
hoary bat captured two hours and five minutes after sunset had only a
partially full stomach.

On May 25, 1951, an unusual concentration of hoary bats was observed at
a pond at about 3200 feet elevation, in San Antonio Canyon (Vaughan,
1953). The day had been clear and warm, one of the first summerlike days
of spring. Beginning at 30 minutes after sundown hoary bats were
collected until two hours and 35 minutes after sundown; in this period
22 were caught and at least as many more observed. Many were released
after being examined, whereupon they hung on the foliage of nearby
alders to rest and dry themselves. This concentration of hoary bats may
have been due to a sudden beginning of migration with a resultant
concentration of bats at certain altitudinal belts. The warm weather
might have set off the migration. On evenings that followed subsequent
hot days no such concentration of hoary bats was seen. B. P. Bole (Hall
1946:156) observed a concentration of hoary bats on August 28, 1932, in
Esmeralda County, Nevada.

Several captive _Myotis californicus_ in a jar next to a pond in San
Antonio Canyon set up a squeaking which seemed to attract a hoary bat.
Repeatedly the large bat swooped over the jar.

_Specimens examined._--Total, 12, distributed as follows: Los
Angeles County: Mescal Canyon, 4900 ft., 2; San Antonio Canyon,
3200 ft., 2; San Antonio Canyon, 2800 ft., 8.

=Antrozous pallidus pacificus= Merriam

Pallid Bat

The pallid bat is probably the most common and characteristic bat of the
citrus belt at the Pacific base of the mountains. Only once, on May 4,
1951, was this bat taken in the mountains. On that night two individuals
were collected at 2800 feet in San Antonio Canyon. All of the other
specimens and observations were from colonies in old barns and
outbuildings in the citrus belt where these bats are found in spring,
summer, and fall.

The impression gained by examining many mixed colonies of _Antrozous_
and _Tadarida_ was that the former greatly outnumbered the latter. For
example, a small colony of bats in an old barn near San Dimas Wash
consisted of about thirty pallid bats and five freetails.

Large numbers of wings of moths of the family _Sphingidae_, and legs and
parts of the heads of Jerusalem crickets (_Stenopelmatus fuscus_) were
beneath an _Antrozous_ night-roosting place in a barn near Upland.

Pallid bats were collected in 1951, from April 16 to October 17 but
probably were active in the area into November.

Each of two pregnant females taken two miles northeast of San Dimas on
April 20, 1951, carried two embryos 4 millimeters long.

_Specimens examined._--Total, 6, distributed as follows: Los
Angeles County: 2 mi. NE San Dimas, 1200 ft., 2 (1PC); Ontario,
1100 ft., 4 (3PC).

Family MOLOSSIDAE

=Tadarida mexicana= (Saussure)

Mexican Free-tailed Bat

This bat, regularly met with in the citrus belt at the coastal base of
the range, occurred in small numbers with colonies of _Antrozous_, and
was once found with a colony of _Eptesicus_ near Covina. None of the
females taken in April 1951 was pregnant.

_Specimens examined._--Los Angeles County: 2 mi. NE San Dimas,
1200 ft., 4.

=Eumops perotis californicus= (Merriam)

Mastiff Bat

H. W. Grinnell (1918:373) mentioned individuals collected at Sierra
Madre (at the coastal base of the San Gabriels west of the study area),
and Sanborn (1932:351) reported specimens from Covina and Azusa.
Probably this bat occurs locally all along the coastal base of the
range.

Family LEPORIDAE

=Lepus californicus bennettii= Gray

California Jack Rabbit

This species was found in the coastal sage belt from Cajon Wash west to
San Gabriel Canyon and was most plentiful in thin stands of sagebrush,
and in and around citrus groves. Because of their preference for
semi-open country, jack rabbits are absent from much of the coastal belt
of sagebrush where the brush is fairly continuous, and they never were
observed in the chaparral association.

Coyotes catch many jack rabbits and regularly forage around the foothill
borders of the citrus groves for cottontails and jack rabbits.

A female examined on February 19, 1951, was pregnant, and one taken on
March 15, 1951, carried three small embryos.

_Specimens examined._--San Bernardino County: 2 mi. NW Upland,
1600 ft., 3 (PC).

=Lepus californicus deserticola= Mearns

California Jack Rabbit

There was sign of jack rabbits along the desert slope of the San
Gabriels up to about 6700 feet, one-half mile west of Big Pines. They
were fairly common in the Joshua tree belt, occurred less commonly in
the juniper belt, and were present locally in small numbers in the
pinyon-juniper association.

The population seemed to be at a low ebb from 1948 to 1952, when field
work was done on the desert slope. I often hiked for an hour or more on
the desert or juniper-covered benches without seeing a jack rabbit. The
species was commoner in washes where as many as eleven were noted in two
hours' hiking.

In December, 1951, below Graham Canyon, the leaves on large areas of
many nearly recumbent Joshua trees had been gnawed down to their bases,
and jack rabbit feces covered the ground next to these gnawings.
Probably the Joshua tree is an emergency food used by the rabbits only
when other food is scarce.

In years when the population of jack rabbits is not low they serve as a
major food for coyotes. In the Joshua tree belt below Mescal Canyon,
jack rabbit remains were fairly common in coyote feces, and tracks
repeatedly showed where some coyote had pursued a jack rabbit for a
short distance. A large male bobcat trapped in the juniper belt in
Graham Canyon had deer hair and jack rabbit remains in its stomach.

_Specimens examined._--Total, 7, distributed as follows: Los
Angeles County: 6 mi. E and 1 mi. S Llano, 3500 ft., 4; Mescal
Canyon, 4800 ft., 3.

=Sylvilagus audubonii sanctidiegi= (Miller)

Audubon Cottontail

Cottontails are common in the coastal sage scrub association and in and
around citrus groves, but generally penetrate the mountains no farther
than the lower limit of the chaparral association. They are everywhere
on coastal alluvial slopes, except in the barren washes, and prefer
patches of prickly-pear and often are loathe to leave its protection.
After completely destroying a large patch of prickly-pear in the course
of examining a wood rat house in the center of the cactus, I found
hiding, in the main nest chamber of the house, a cottontail that dashed
from its hiding place only when poked forceably with the handle of a
hoe.

Cottontails are seldom above the sage belt in the chaparral
associations, although along firebreaks and roads they occasionally
occur there. Habitually cottontails escape predators in partly open
terrain offering retreats such as low, thick brush, rock piles, and
cactus patches; but on open ground beneath dense chaparral, cottontails
may be vulnerable to predation.

Examinations of feces and stomach contents of the coyote reveals that it
preys more heavily on cottontails than on any other wild species.
Remains of several cottontails eaten by raptors were found in the sage
belt.

In April, 1951, many young cottontails were found dead on roads in the
sage belt, and a newly born cottontail was in the stomach of a coyote
trapped four miles north of Claremont, on February 7, 1952.

_Specimens examined._--Total, 3, distributed as follows: Los
Angeles County: mouth of San Antonio Canyon, 2000 ft., 1 (PC).
San Bernardino County: 2 mi. NW Upland, 1600 ft., 2 (PC).

=Sylvilagus audubonii arizonae= (J. A. Allen)

Audubon Cottontail

This subspecies was recorded on the interior slope from 5200 feet
elevation, as at the head of Grandview Canyon, down into the desert, and
was common in the sagebrush flats of the upper pinyon-juniper
association. Piles of feces under thick oak and mountain-mahogany
chaparral indicated that the rabbits often sought shelter there.
Adequate cover is a requirement for this rabbit on the desert slope of
the San Gabriels; in the juniper and Joshua tree belts the species
occurs in washes where there is fairly heavy brush, and only
occasionally elsewhere. In the foothills, when frightened from cover in
one small wash cottontails often run up over an adjacent low ridge and
seek cover in the brush of the next wash. In the wash below Graham
Canyon tracks and observations showed that cottontails were taking
refuge in deserted burrows of kit foxes.

In the pinyon-juniper association cottontails and jack rabbits probably
occur in roughly equal numbers, but in the Joshua tree belt cottontails
seem far less numerous than jack rabbits. In the course of a two hour
hike in lower Mescal Wash, at about 3500 feet, eleven jack rabbits and
two cottontails were noted.

_Specimens examined._--Total, 2, distributed as follows: Los
Angeles County: 6 mi. E and 1 mi. S Llano, 3500 ft., 1; Mescal
Canyon, 4800 ft., 1.

=Sylvilagus bachmani cinerascens= (J. A. Allen)

Brush Rabbit

Brush rabbits inhabit the Pacific slope of the mountains from about 1200
feet in the coastal sagebrush belt up to at least 4500 feet in the
chaparral, and are the only lagomorphs found commonly above the lower
edge of the chaparral association. Here they were often on steep slopes
beneath extensive and nearly impenetrable tracts of chaparral.

The ecologic niche of the brush rabbit is in brush where the plants form
continuous thickets with little open ground. In the coastal sagebrush
flats, areas supporting only scattered bushes are uninhabited by brush
rabbits, while areas grown to extensive tracts of brush harbor them.
When the brush rabbit's mode of escape from its enemies is considered,
the reason for their habitat preference becomes more clear. Almost
invariably these rabbits seek escape by running through the densest
portions of the brush, never appearing in the open; in this way they
travel quickly away from the source of danger without being observed.
Because they avoid being seen in the open, and do not seek safety
largely through running ability, they need continuous stretches of brush
for escape. While hunting in the coastal sagebrush belt I have
repeatedly seen frightened brush rabbits turn and dart beneath the
bushes a few feet from a human being rather than be driven into the
open.

A great horned owl shot in March, 1951, in the sage belt, had in its
stomach the remains of a freshly killed adult brush rabbit. Although
coyotes and brush rabbits often occur in the same general sections of
the sage flats, remains of these rabbits have been notably scarce in
coyote feces from these areas. This is probably because the coyote hunts
along clearings and in open brushland, precisely the type of habitat
avoided by brush rabbits.

Family SCIURIDAE

=Sciurus griseus anthonyi= Mearns

Western Gray Squirrel

Gray squirrels were on both slopes of the San Gabriels in oak woodland.
A gray squirrel was observed in April of 1948, as it climbed a telephone
pole adjacent to an orange grove near Cucamonga. This, and one noted
bounding up a slope of greasewood chaparral near Cattle Canyon, were the
only gray squirrels seen in areas which were not grown to oaks or
adjacent to oak woodland. In the lower foothills gray squirrels were
invariably found in association with valley oak, this plant forming
limited woodland areas in canyon bottoms. In the upper chaparral
association the squirrels frequented the large scrub oaks growing on
talus slopes and canyon sides. In the yellow pine woodland, gray
squirrels are restricted to black oaks, often where they formed mixed
stands with the conifers. On the interior slope these squirrels were
found only at the lower edge of the yellow pine woodland where black
oaks are common. There, in the vicinity of Big Pines, they were present
between roughly 5800 and 7000 feet, while on the Pacific slope they
inhabited oak woodland from 1600 feet to about 7000 feet elevation.

In Live Oak Canyon in December of 1950, tracks indicated that a bobcat
had killed a gray squirrel in a small draw beneath the oaks. In Evey
Canyon on March 6, 1951, while watching for bats at late twilight, I
observed a gray squirrel traveling through the branches of a nearby oak.
A great horned owl glided into the oak in an attempt to catch the
squirrel, which leaped quickly into a dense mass of foliage and escaped.
For roughly ten minutes the owl perched in the oak watching its intended
prey, then flew off down the canyon amid frantic scolding by the
squirrel.

On March 17, 1951, a female gray squirrel taken at about 3500 feet
elevation in San Antonio Canyon contained two embryos, each roughly 40
millimeters long.

=Spermophilus beecheyi beecheyi= (Richardson)

Beechey Ground Squirrel

From the coastal sage belt, into the yellow pine forest of the Pacific
slope, this species is common on land cleared by man or disturbed in the
course of construction, or on severely eroded slopes where the original
climax vegetation is partly or completely absent. Thus in the sage belt,
ground squirrels live along dirt roads through the brush, on the heavily
eroded banks often found in the foothills, on land grazed closely by
sheep, and in those parts of major washes such as San Antonio and
Cucamonga washes where scatterings of huge boulders offer prominent
vantage points. In San Antonio Canyon _Spermophilus_ was restricted to
the vicinity of roads and firebreaks, and an especially large colony of
at least forty individuals lived at a dump one mile southwest of Camp
Baldy at about 4500 feet elevation. Ground squirrels used burned stems
of large laurel sumac as observation posts. Because of a preference for
open areas offering unobstructed outlooks, ground squirrels originally
probably did not penetrate the main belt of heavy chaparral on the
Pacific slope of the range except in some of the large washes.

In the spring of 1951 and the preceding summer there was a marked
increase in the ground squirrel population near Padua Hills as a
result of sheep grazing on approximately one-half square mile of sage
land. Grasses and smaller shrubs were eaten down to the ground, and in
some places coastal sagebrush and _Haplopappus_ were killed by browsing
and trampling. The area formerly had a sparse growth of bushes with
intervening growths of tall grasses and one colony of perhaps 20 ground
squirrels; but after the sheep grazing the area was open brushland with
large clear spaces on which the herbage was trimmed to the ground, and
had at least four colonies of ground squirrels as large as the first.
Also there were other ground squirrels established in various parts of
the area. Probably the dry weather in the winter of 1950-51 with
consequent retardation of the vegetation aided the spread of the
squirrels in this area.

In the sage belt, most ground squirrels are dormant by December. In
1951, after a mild winter, squirrels were noted on January 25 near Padua
Hills. On February 8, 1951, males in breeding condition were collected,
and on March 16, a female taken near San Antonio Wash carried three
small embryos. In early March of 1951, ground squirrels were active at
4500 feet elevation in San Antonio Canyon.

_Specimen examined._--Los Angeles County: 1 mi. S and 2 mi. E
Big Pines, 8000 ft., 1.

=Spermophilus beecheyi fisheri= (Merriam)

California Ground Squirrel

This ground squirrel inhabited the desert slope of the mountains up to
5000 feet elevation, and was most common in the juniper belt; burrows
often were made under large junipers. In May, 1949, ground squirrels
were common in the rocks adjacent to Mescal Wash at an elevation of 4500
feet. In an apple orchard near Valyermo, squirrels fed on the fallen
fruit in early November of 1951.

No squirrel was seen in December, January, and February, indicating that
all were below ground in winter.

_Specimen examined._--San Bernardino County: Desert Springs,
4000 ft., 1 (PC).

=Ammospermophilus leucurus leucurus= (Merriam)

Antelope Ground Squirrel

Antelope ground squirrels were common in the Joshua tree woodland where
they were noted up to 4500 feet elevation in Graham Canyon. None was
found on the pinyon slopes, possibly because of the competition offered
there by _Eutamias merriami_, or because the rocky nature of the soil
there rendered burrowing difficult.

Although observed less often in winter than in summer, this species is
active all year. On February 6, 1949, in Mescal Wash, an antelope ground
squirrel was foraging over the snow which was at least six inches deep.
These squirrels were attracted to the carcasses of rodents used as bait
for carnivore sets, and caused a good deal of trouble by disturbing the
traps.

Antelope ground squirrels used the topmost twigs of box-thorn bushes
extensively as lookout posts, and many of their burrows were at the
bases of these thorny bushes. This habit of regularly using observation
posts is well developed in each species of ground squirrel found in the
San Gabriels.

_Specimens examined._--Los Angeles County: 6 mi. E and 1 mi. S
Llano, 3500 ft., 2.

=Eutamias speciosus speciosus= (Merriam)

Lodgepole Chipmunk

This chipmunk was characteristic of the most boreal parts of the San
Gabriel Mountains. It was recorded from 6800 feet elevation at Big
Pines, to an altitude of approximately 9800 feet near Mt. San Antonio,
and was common where coniferous timber was interspersed with snowbrush
chaparral. In upper Icehouse Canyon and near Telegraph Peak these
chipmunks were associated with lodgepole pines and chinquapin, and one
mile east of Mt. San Antonio individuals were often observed in thickets
of manzanita. This chipmunk usually shunned pure stands of coniferous
timber except as temporary forage ground.

On Blue Ridge these chipmunks used the uppermost stems of snowbrush as
vantage points, and when disturbed ran nimbly over thorny surfaces of
the brush in seeking refuge in the tangled growth.

In early November of 1951, these animals were not yet in hibernation on
Blue Ridge. They were noted on November 6, after the season's first
snows had melted; on November 13, however, a cold wind with drifting fog
kept most of them under cover, and only two were noted in the course of
the day.

_Specimen examined._--Los Angeles County: 1 mi. S and 2 mi. E
Big Pines, 8100 ft., 1.

=Eutamias merriami merriami= (J. A. Allen)

Merriam Chipmunk

The lower limit of the range of this species, on the coastal face of the
range, is roughly coincident with that of manzanita--that is to say, it
begins in the main belt of chaparral above the lower foothills. _E.
merriami_ seems to reach maximum abundance amid the granite talus, and
scrub oak and _Pseudotsuga_ growth at the upper edge of the chaparral
association. It was absent, however, from all but the lower fringe of
the yellow pine forest association.

On the desert slope _merriami_ was partial to rocky areas in the
pinyon-juniper association but was also in the black oak woods on the
Ball Flat fire road near Jackson Lake. Nowhere was _Eutamias merriami_
and _E. speciosus_ observed on common ground.

_Specimens examined._--Los Angeles County: San Antonio Canyon,
5500 ft., 2 (1 PC).

=Glaucomys sabrinus californicus= (Rhoads)

Northern Flying Squirrel

No specimens of this species were taken in the field work in the San
Gabriels, nor did I find any rangers or residents of the mountains who
had seen flying squirrels in the area. Nevertheless sign found in the
white fir forests in the Big Pines area indicated that flying squirrels
may occur there. On a number of occasions dissected pine cones were
noted on the horizontal limbs and bent trunks of white firs. These cones
were too large to have been carried there by chipmunks, and gray
squirrels were often completely absent from the areas. I suspect that
extensive trapping in the coniferous forests of the higher parts of the
mountains would produce specimens of flying squirrels. Willett (1944:19)
mentions that flying squirrels probably occur in the San Gabriel
Mountains.

Family GEOMYIDAE

=Thomomys bottae pallescens= Rhoads

Valley Pocket Gopher

This gopher was found below about 5000 feet elevation in disturbed or
open areas from Cajon Wash at Devore westward all along the coastal base
of the San Gabriel Range. In the lower part of the chaparral belt the
gopher evidently was absent from the chaparral-covered slopes, but was
common along roads and on fire trails.

Burt (1932) and von Bloeker (1932) discuss the distribution of the three
subspecies of this species, _pallescens_, _neglecta_, and _mohavensis_,
which are in the San Gabriel Mountains area, and Burt indicates that
_pallescens_ grades toward _mohavensis_ in the southern part of Antelope
Valley.

=Thomomys bottae neglectus= Bailey

Valley Pocket Gopher

In the forests of yellow pine and white fir of the higher parts of the
San Gabriel Mountains the workings of this gopher were common, and sign
of its presence was found above 4500 feet on both slopes of the mountain
range. The rocky character of the coastal slope seems to limit the
occurrence of gophers, for they are not continuously distributed there.
On the desert slope they occur locally down into the pinyon-juniper
belt.

In the vicinity of Big Pines, on the interior slope, these gophers
preferred broken forest where snow brush or other brush occurred; their
workings, however, were also found beneath groves of conifers and black
oaks. The abundance of earth cores resting on the duff indicated that
this species is active in the snow in winter.

_Specimens examined._--Total, 5, distributed as follows: Los
Angeles County: 2 mi. E Valyermo, 4600 ft., 2; 3 mi. W Big
Pines, 6000 ft., 1; 1 mi. S and 2 mi. E Big Pines, 8000 ft., 2.

=Thomomys bottae mohavensis= Grinnell

Valley Pocket Gopher

One specimen of this subspecies was taken on December 31, 1951, in the
Joshua tree belt, eight miles east of Llano, 3700 feet elevation.

Family HETEROMYIDAE

=Perognathus fallax fallax= Merriam

San Diego Pocket Mouse

This pocket mouse is restricted to the coastal sage scrub association,
and was recorded from Cajon Wash west to Live Oak Canyon. The mouse does
not inhabit even the lower edge of the chaparral belt, but in the
coastal sage flats is usually the most abundant rodent. In disturbed
parts of the coastal sage belt _fallax_ is less common, and was never
trapped in channels of rocky washes. Trap lines in the eroded adobe
banks of the foothills, where white sage and coastal sagebrush are the
dominant plants, took mostly these pocket mice. Although the soil of
such slopes is compact and seemingly is unsuitable for burrowing by
heteromyids, _fallax_ is the most common rodent. Because few burrows of
pocket mice were noted there, it is possible that the many old unused
burrows of _Spermophilus_ and _Dipodomys_ which honeycomb certain parts
of adobe banks are used also by _fallax_; some of these burrows
shelter _Peromyscus eremicus_ and _Peromyscus californicus_.

These mice are inactive above ground in cold weather. In the sage belt
near Thompson Canyon, where this subspecies had been found to be the
most common rodent, none was trapped on the sub-freezing night of
December 3, 1948, although other rodents were found in usual numbers.
Individuals have been taken on nights of intermittent rain, yet none has
been trapped on freezing nights.

This species is characteristically heavily infested by a large species
of mite. Usually these mites congregate around the base of the tail.

On October 11, 1949, one lactating female and two carrying embryos were
taken.

_Specimens examined._--Total, 11, distributed as follows: Los
Angeles County: 4 mi. N and 1 mi. E Claremont, 1900 ft., 5; 3
mi. N Claremont, 1600 ft., 6 (5 PC).

=Perognathus fallax pallidus= Mearns

San Diego Pocket Mouse

On the desert slope of the mountains this species is found in the part
of the pinyon-juniper association that is between elevations of 4000 and
5200 feet. The mouse is absent from the higher chaparral and
pinyon-covered slopes, but is present on south slopes in the pinyon belt
where more open growths of pinyons and scrub oaks are interspersed with
yucca. I recorded this pocket mouse from the vicinity of Cajon Pass west
to Valyermo.

The local distribution of _pallidus_ is striking because of its close
positive correlation with the distribution of yucca. On benches around
5000 feet, where yuccas are scattered in their occurrence, _pallidus_ is
nearly always taken near (often right at the base of) this plant. Lower
in the juniper belt the dry rocky south slopes supporting yucca plants
are well populated by _pallidus_, while adjacent flats, and north slopes
grown to antelope brush and scrub oak, are completely uninhabited. Near
the mouth of Grandview Canyon, on steep rocky southern exposures grown
sparsely to burro weed and yucca, one hundred traps produced in one
night eight _pallidus_ and no other rodents. Here many of these pocket
mice were trapped on large fractured rock outcroppings, where most or
all of the mice probably lived in the daytime in the deep cracks; in any
event no burrows were noted near these rocks.

This species prefers barren slopes supporting yucca plants. These plants
produce large seeds which are staple food items for _P. f. pallidus_ and
other rodents during the lean part of the year, that is to say, late
summer and autumn. Many of the dry capsules of the yucca plants were
examined in October, 1951, and these generally still contained a few
seeds. Pocket mice taken in October usually carried in their cheek
pouches seeds of yucca together with some other material, and often they
carried only the seeds of yucca. Probably the wind shakes only a few
seeds out of the capsules at a time, thus tending to drop the seeds over
a fairly long period.

Trapping in winter in the juniper belt revealed that these pocket mice
were not active above ground on nights colder than about 40° F. On
nights when the temperature was about 36° F. none was taken, but on the
one night in late December, 1948, when the minimum was 44° F., several
specimens were taken. In this same area in May 1949, pocket mice were
the most numerous rodents. Because of their evident sensitivity to cold
weather, these mice must remain below ground for weeks at a time during
the cold weather of December and January.

Specimens of _pallidus_ from the desert slope of the San Gabriels are
grayer (less brown) than specimens taken farther southeast in the Mojave
and Colorado deserts. Further sampling of populations of _Perognathus
fallax_ from areas adjacent to the San Gabriels might demonstrate
differences of sufficient magnitude to warrant subspecific distinction
of the San Gabriel population. Possibly, however, the San Gabriel series
manifests only local variation in the race _pallidus_. Grinnell
(1933:54) characterizes the ecological niche of the race _pallidus_ as
being "open, sandy ground, often ... surrounded by rocky slopes,"
whereas these pocket mice in the San Gabriels inhabited gravelly or
rocky juniper-dotted benches.

_Specimens examined._--Total, 11, distributed as follows: Los
Angeles County: 5 mi. E and 4 mi. S Llano, 4500 ft., 7; 2 mi. E
Valyermo, 4500 ft., 3; 4 mi. E Valyermo, 5000 ft., 1.

=Perognathus californicus dispar= Osgood

California Pocket Mouse

Mice of this subspecies were recorded from the lower chaparral
association below about 4000 feet elevation along the coastal face of
the San Gabriel Range. They were trapped on greasewood-covered slopes,
in mixed growths of white sage and buckwheat, and beneath scrub oak
and lilac chaparral; however none was taken in the heavy chaparral of
the upper parts of the chaparral association.

One small juvenile in gray pelage was taken in San Antonio Canyon on
October 1, 1951.

_Specimens examined._--Total, 5, distributed as follows: San
Bernardino County: Lytle Canyon, 4000 ft., 2 (PC). Los Angeles
County: San Antonio Canyon, 3000 ft., 3.

=Perognathus californicus bernardinus= Benson

California Pocket Mouse

On Blue Ridge these mice were recorded between 7100 and 8000 feet
elevation. Here they were restricted to dense tracts of snowbrush and
sagebrush, often where these tracts were interspersed with, or beneath,
open groves of conifers. These mice seemed to favor areas where this
thick brush was broken by patches of open, grass-covered ground. Benson
(1930:450) records this subspecies from Swarthout Valley, near Big
Pines, at 6860 feet elevation.

While setting traps for pocket gophers one mile southwest of Big Pines,
in September of 1951, I frightened a pocket mouse from its burrow. The
animal jumped into the tangle of interlacing twigs of a nearby clump of
snowbrush, and with great dexterity climbed into the center of the bush,
where it was lost to view. I was surprised at the facility with which
this saltatorial rodent traveled through the network of small branches.

In winter, in areas inhabited by this mouse, snow covers the ground for
long periods during which these mice are probably forced to remain below
ground.

_Specimens examined._--Los Angeles County: 1 mi. S and 2 mi. W
Big Pines, 7400 ft., 2.

=Dipodomys panamintinus mohavensis= (Grinnell)

Panamint Kangaroo Rat

This rat is common in the Joshua tree and juniper belts, and locally
penetrates the pinyon belt at about 5000 feet elevation. It occurs
regularly along the entire desert slope of the San Gabriel Mountains.

The upper limit of the range of this species roughly coincides with the
upper limit of the juniper belt, and within this range it was found to
inhabit areas having widely different soil types. It occurred on the
sandy ground of desert washes, the gravelly soil of the juniper-clad
benches, and the mixed sandy and rocky ground of washes in canyons. A
preference is shown by _panamintinus_ for fairly level ground. Rough
terrain or steep slopes are generally avoided, whereas rather large
colonies of these kangaroo rats are found in small flats of the desert
foothills.

Below about 4500 elevation on the interior slope this species was the
most numerous rodent, and seemed to reach maximum abundance in the
Joshua tree association. About 500 trap-nights in the juniper belt near
Graham Canyon yielded 31 specimens, whereas about 300 trap-nights in
Joshua tree flats took 34 individuals.

The cheek pouches of many specimens taken in early winter contained
green shoots of grass and little dry material. On many occasions rat
traps set next to wood rat nests beneath large junipers produced
_panamintinus_, and many of these animals had their cheek pouches
crammed full of juniper berries.

In December, 1948, _panamintinus_ was trapped consistently on nights
when the temperature dropped to below 20° F. On December 27, 1948, after
a three inch snowfall, tracks of this species were noted in the snow at
the mouth of Mescal Canyon.

Parts of the skulls of this species were found in many coyote feces from
the desert slope.

_Specimens examined._--Total, 11, distributed as follows: Los
Angeles County: Mescal Wash, 4000 ft., 8 (6 PC); 2 mi. E
Valyermo, 4600 ft., 3.

=Dipodomys merriami merriami= Mearns

Merriam Kangaroo Rat

This kangaroo rat barely enters the area under consideration and is
almost restricted to the Joshua tree association, for only a few
individuals were taken at the lower edge of the juniper benches. This
species inhabits the Joshua tree belt all along the desert base of the
San Gabriels.

As mentioned in the description of the Joshua tree association, the
relative numbers of _Dipodomys merriami_ and _D. panamintinus_ shifted
from 1948 to 1951, possibly concurrent with the seasons of low rainfall
in this period. Whereas in 1948 _merriami_ was decidedly less abundant
than _panamintinus_ in the Joshua tree belt, in 1951 the numbers were
reversed.

In December, 1951, it was found by tending the traps in the early
evening that _merriami_ foraged fairly early before the ground had
frozen solidly.

_Specimens examined._--Los Angeles County: 2 mi. NW mouth of
Graham Canyon, 3500 ft., 5 (PC).

=Dipodomys merriami parvus= Rhoads

San Bernardino Kangaroo Rat

One specimen of this subspecies was trapped on November 26, 1951, in a
sandy channel of Cajon Wash near Devore beneath a clump of scale-broom.

=Dipodomys agilis agilis= Gambel

Pacific Kangaroo Rat

This species was found below about 4000 feet elevation all along the
coastal face of the range and reached maximum abundance in the level
tracts of coastal sage. It was one of the most abundant rodents there,
usually being second to _Perognathus fallax_ in point of numbers. Large
colonies of kangaroo rats occurred locally on sandy ground adjacent to
large washes. The rats were found sparingly on the foothill adobe banks
and in the greasewood chaparral of the lower foothills, but in heavy
chaparral where a layer of plant debris covered the ground, such as on
north slopes grown to scrub oak and lilac, kangaroo rats were completely
absent. Thus, in the lower chaparral belt, this rodent had a
discontinuous distribution.

The coyote probably is one of the major predators of these kangaroo
rats; remains of this rodent were often found in coyote feces, and
coyotes excavated many burrow systems in large kangaroo rat colonies in
the sandy ground near San Antonio Wash. The soil there is so soft that
coyotes probably were often successful in digging out their prey. The
shed skin of a large Pacific rattlesnake (_Crotalus viridis helleri_)
was found four feet inside the mouth of a kangaroo rat burrow; probably
this reptile preys on _agilis_. Great horned owls (_Bubo virginianus
pacificus_) come down nightly from the chaparral to hunt in the sage
flats. Beneath the perches of these owls I have found pellets containing
bones of _agilis_.

_Specimens examined._--Total, 13, distributed as follows: Los
Angeles County: San Antonio Wash, 1900 ft., 11 (10 PC); 4 mi. NE
Claremont, 1600 ft., 2.

=Dipodomys agilis perplexus= (Merriam)

Pacific Kangaroo Rat

All the specimens of this species from the desert slope of the San
Gabriel Range are referred to the subspecies _perplexus_. They were
taken in brushy habitats between the elevations of 4500 and 7400 feet.
Throughout much of this area _perplexus_ was found only in certain
restricted areas more or less surrounded by inhospitable ground. For
example, at 7400 feet on Blue Ridge, they were found occasionally in the
strips of sagebrush and lilac brush which locally capped this ridge.
Often these patches of chaparral on Blue Ridge were surrounded by areas
unsuitable for kangaroo rats: on the Pacific slope, talus, oaks, and
yellow pines prevailed; on the ridge scattered yellow pine groves were
present; and on the steep desert slope there were yellow pines and white
firs. In Swarthout Valley _perplexus_ was found in flats that supported
basin sagebrush and _Haploppus_, while the coniferous forests to the
south, and pinyon-covered slopes to the north were uninhabited. On flats
supporting antelope brush and juniper, _perplexus_ was often common, but
it did not penetrate the chaparral of adjacent slopes grown to scrub oak
and mountain-mahogany. In general then, _perplexus_ was found in fairly
open brushy flats or slopes, even where these were surrounded by
unsuitable habitats.

Specimens of _D. agilis_ from the desert slope two miles east of
Valyermo are referrable to the subspecies _perplexus_. A series taken in
Cajon Wash at Devore, on the Pacific slope, is intermediate between
_agilis_, of the coastal slope of the San Gabriels, and _perplexus_ of
the desert slope, but approaches more nearly the later subspecies. Thus,
different subspecies of _D. agilis_ occur on opposite slopes of the San
Gabriel Mountains, with intergradation taking place in the Cajon Pass
area and probably also at the west end of the Mountains.

Both scrub oak acorns and juniper berries were found in the cheek
pouches of this subspecies, and one immature individual taken in
Swarthout Valley had its cheek pouches stuffed with approximately 550
seeds of brome grass.

On November 13, 1951, at 7500 feet on Blue Ridge, a small juvenile was
taken; it must have been born not earlier than September.

_Specimens examined._--Total, 17, distributed as follows: Los
Angeles County: 2 mi. E Valyermo, 4600 ft., 3; 5 mi. E Valyermo,
1; 1 mi. E Big Pines, 6600 ft., 6; 1 mi. S and 2 mi. W Big
Pines, 7400 ft., 2. San Bernardino County: Cajon Wash, 1/2 mi.
SW Devore, 2200 ft., 5.

Family CRICETIDAE

=Reithrodontomys megalotis longicaudus= (Baird)

Western Harvest Mouse

This species inhabited grassy areas of the coastal sage belt, and
reached maximum abundance on cleared land grown thickly to weeds and
scattered brush. The mouse was only locally abundant--being scarce
throughout much of the sage belt--but was found under contrasting
conditions. In San Antonio Wash the species was taken among rocks and
sparse weeds, at Palmer Canyon specimens were trapped on a barren ridge
sparsely clothed with greasewood and white sage, and also one mile E of
Big Pines in flats supporting basin sagebrush and a fairly dense growth
of grasses. The western harvest mouse was recorded from 1500 feet
elevation to 3200 feet on the Pacific slope, and at 6600 feet near Big
Pines on the desert slope.

Those specimens of harvest mice from near Big Pines may be grading
toward the desert race _megalotis_; my series of specimens from this
locality, however, is too small for clear indications on this point.

Individuals in juvenal pelage were taken on November 26, 1951, near
Devore.

_Specimens examined._--Total, 6, distributed as follows: Los
Angeles County: 1 mi. E Big Pines, 6600 ft., 2; Palmer Canyon,
2000 ft., 1; 4 mi. N Claremont, 1700 ft., 3 (PC).

=Peromyscus eremicus eremicus= (Baird)

Cactus Mouse

In Mescal Wash on the desert slope of the San Gabriels, this mouse was
one of the most abundant mammals and was the only rodent other than
_Peromyscus maniculatus_ regularly trapped in the barren channels of
washes. In Mescal Wash, at an altitude of 4000 feet, _eremicus_ occurred
along with the chaparral-inhabiting _Peromyscus boylii_ and _Peromyscus
californicus_. The two species last mentioned were associated with the
occasional large patches of manzanita, antelope brush, and other brush
of the wash, whereas _eremicus_ was trapped in the rocky and sandy
channels among scattered bushes of scale-broom. No specimens of
_eremicus_ were taken on the juniper-clad benches adjacent to the wash.

_Specimens examined._--Los Angeles County: Mescal Wash, 4000
ft., 10 (4 PC).

=Peromyscus eremicus fraterculus= (Miller)

Cactus Mouse

This mouse was recorded from 1900 feet elevation, one mile south of the
mouth of San Antonio Canyon, to 3200 feet elevation in Cajon Canyon.
This subspecies is characteristic of the sage belt and shows a strong
preference for the rough rocky areas found in dry washes. Although in
many areas the channels of the washes are immediately adjacent to sandy
sagebrush-covered flats, _eremicus_ is not common in the latter areas.
Rocks seem to be essential to _eremicus_, for sandy areas in the
sageland which were devoid of rocks yielded only an occasional specimen.
For example, 100 trap-nights in the main channel of San Antonio Wash
yielded 23 _eremicus_ and only six other rodents; while in the sandy
sage areas nearby 200 trap-nights yielded only one _eremicus_ and 32
other rodents.

In lower San Antonio Canyon _eremicus_ seemed restricted to the rocky
canyon bottom, none having been trapped on the steep slopes nearby. This
subspecies occurs commonly, however, on the adobe banks grown to white
sage at the base of the foothills. There _eremicus_ occurred on common
ground with _Perognathus fallax fallax_, and was often the only
_Peromyscus_ taken.

This species may be restricted by temperature; washes above 4000 feet
elevation, which seemed suitable were uninhabited by these mice.

On December 1, 1949, two females taken at the mouth of Palmer Canyon had
well advanced embryos. A female trapped in San Antonio Canyon on
September 19, 1951, was lactating. Juveniles were caught in the sage
belt in October, 1951.

_Specimens examined._--Total, 6, distributed as follows: Los
Angeles County: San Antonio Canyon, 2500 ft., 1; San Antonio
Wash, 1800 ft., 5 (PC).

=Peromyscus californicus insignis= Rhoads

California Mouse

This mouse inhabits areas supporting chaparral on the coastal slope of
the San Gabriels below 5000 feet. In the chaparral it is usually the
most plentiful rodent, being dominant on slopes which have been burned
over and on which greasewood chaparral has taken over. On one such slope
at the head of Cow Canyon, at 4500 feet, this was the only rodent
trapped, although an occasional wood rat house was noted. Trapping
records gave the impression that this form was the most ubiquitous
rodent in the entire chaparral belt. Nearly every trap line, even in
such non-productive areas as oak woodland, took the California mouse;
and in many areas, as in thick lilac brush, this mouse was by far the
most abundant rodent. Specimens were taken on the damp ground next to
San Antonio Creek, and in the riparian growth. In San Antonio Wash the
California mouse was found in thickets of laurel sumac and lemonade
berry, or other large shrubs, but were absent from most of the adjacent
sageland. The one place where they were found away from heavy brush was
on a series of barren adobe banks, near Palmer Canyon, clothed mostly
with white sage. Here they found shelter in the unused burrows of
kangaroo rats and ground squirrels.

The only place on the desert slope where this species was taken was in
Mescal Wash. There it was taken occasionally near the large clumps of
antelope-brush and manzanita which grew in the main channels of the
wash.

Lactating females of this species were taken in October, 1949, and
February, 1950. Two pregnant females were trapped on February 25, 1950,
at the mouth of Palmer Canyon.

_Specimens examined._--Total 16, distributed as follows: Los
Angeles County: Mescal Wash (4200 ft., 4; 4300 ft., 1; 4500 ft.,
1), 6(2IM); San Antonio Canyon, 4500 ft., 1; San Antonio Canyon,
3000 ft., 5; mouth of Palmer Canyon, 1900 ft., 4 (PC).

=Peromyscus maniculatus gambeli= (Baird)

Deer Mouse

This species occurs from 1000 feet elevation to above 9000 feet
elevation on the Pacific slope of the Mountains, but although probably
the most widespread rodent in the area it is absent from many habitats.
This mouse reaches maximum abundance in the coastal sage scrub
association, particularly where the soil is sandy with scattered
vegetation--usually coastal sagebrush and black sage. On the foothill
adobe slopes none was trapped, nor have any been taken in most of the
chaparral habitats. A few _gambeli_ were trapped amid the talus beneath
growths of scrub oak and bay trees in San Antonio Canyon, at 4300 feet
elevation. On Blue Ridge, at elevations of from 7200 feet to 8300 feet,
this mouse inhabited areas clothed with snowbush, basin sagebrush,
currant, and scattered conifers, and was found sparingly in the
coniferous forests. Thus this species lives on contrasting soil types in
association with many different vegetational assemblages, from the
coastal base to the crest of the range.

There is a rather wide variation in color in _gambeli_ from the San
Gabriels. Certain individuals taken in open, sandy coastal sage areas
are pale, some being indistinguishable from examples of _sonoriensis_
taken in the pinyon-juniper association on the desert slope. Specimens
from San Antonio Canyon have somewhat darker pelage than those from the
sage belt, and than individuals taken on Blue Ridge. Possibly a large
series of _Peromyscus maniculatus_ from the San Gabriel Mountains would
show definite local trends in color of pelage.

This species is active on sub-freezing and rainy nights as evidenced by
trapping results, and at Big Pines there were tracks around the bases of
conifers after a heavy snowfall in December, 1951. Several females
taken in the sage belt in October, 1948, carried embryos, and a
lactating female was recorded from Blue Ridge on November 13, 1951.
Juveniles have been taken in September, October, November, and December.

_Specimens examined._--Total, 9, distributed as follows: Los
Angeles County: 1 mi. S and 2 mi. W Big Pines, 7400 ft., 3; 1
mi. S and 2 mi. E Big Pines, 8200 ft., 1; 4 mi. NE Claremont,
1900 ft., 2; San Antonio Wash, 1800 ft., 3 (PC).

=Peromyscus maniculatus sonoriensis= (Le Conte)

Deer Mouse

This subspecies is associated with contrasting types of soil and
vegetation. It is seemingly absent from the upper pinyon-juniper sage
flats and areas grown to chaparral, but is fairly common on the gravelly
benches dotted with junipers, and in the washes issuing from the canyons
on the desert slope. It is present in small numbers in the Joshua tree
association.

In 1951 the numbers of _sonoriensis_ were noticeably less than in 1948;
probably this was correlated with the series of dry winters in this
period. In December, 1948, this animal was one of the most common
rodents in Mescal Wash, 200 trap-nights yielding thirteen specimens; but
in November, 1951, none was taken. In parts of the juniper belt, where
an average of about six _sonoriensis_ was taken per 100 trap-nights in
1948, the average had dropped to one per 100 trap-nights in 1951.

Specimens of this species from the desert slope of the mountains have
been assigned to the subspecies _sonoriensis_. Those from Blue Ridge
tend toward _sonoriensis_ in color, and may be considered as intergrades
between this subspecies and _gambeli_.

This species was active on nights when the temperature was as low as 10°
F., and individuals were trapped in the juniper belt in December, 1948,
when four inches of snow lay on the ground.

Gray-pelaged juveniles were taken on the desert slope in December, 1948,
and a female taken in Mescal Canyon on December 22 of this year carried
four embryos near term.

_Specimens examined._--Total, 11, distributed as follows: Los
Angeles County: 8 mi. E and 4 mi. S Llano, 4000 ft., 6 (4 PC);
Mescal Canyon, 4800 ft., 5.

=Peromyscus boylii rowleyi= (J. A. Allen)

Brush Mouse

The main range of this mouse in the San Gabriel Mountains lies between
1600 and 6000 feet elevation on the Pacific slope of the Mountains, thus
encompassing much of the chaparral and oak woodland associations. It
was the most common mammal in the oak woodland association in the lower
foothills and often was trapped there on leaf mold beneath the oaks.
While trapping for shrews I regularly took this species in riparian
growth right down to the edge of the water. In San Antonio Canyon many
_boylii_ were trapped beneath logs and dense vegetation, and on wet
seepage slopes adjacent to the creek.

This species shows a definite predilection for rocky habitats where
these occur in the chaparral. In heavy lilac brush near Camp Baldy
_Peromyscus boylii_ was outnumbered by _P. californicus_, yet where
talus slopes or boulder piles occurred _boylii_ was more numerous. At
the head of Cow Canyon amid boulders beneath scrub oak, bay, and big
cone-spruce, this species was especially abundant and no other
_Peromyscus_ was taken.

Of special interest is the occurrence of this mouse on the desert slope
of the mountains; there it was taken beneath scrub oaks in the
pinyon-juniper association at the mouth of Mescal Canyon, and amid
boulder and debris piles in Mescal Wash at 4000 feet elevation. While
manzanita and scrub oak grew in the wash at the points of capture, the
animals were actually surrounded by the desert conditions of the Joshua
woodland, and associated with such desert forms as _Onychomys torridus
pulcher_ and _Peromyscus eremicus eremicus_.

Immature individuals were taken in October, November, February, and
March, and a female with two large embryos was taken near Icehouse
Canyon on November 8, 1951.

_Specimens examined._--Total, 8, distributed as follows: Los
Angeles County: Mescal Wash, 4000 ft., 1; Mescal Canyon, 4800
ft., 2; San Antonio Canyon, 5200 ft., 2; San Antonio Canyon,
4500 ft., 1; San Antonio Canyon, 2800 ft., 1; Thompson Canyon,
1800 ft., 1 (PC).

=Peromyscus truei montipinoris= Elliot

Piñon Mouse

Only once was this mouse found outside the pinyon-juniper association of
the desert slope; in November, 1949, several were collected near Cajon
in mixed manzanita, scrub oak, and greasewood chaparral. This was the
only _Peromyscus_ of regular occurrence in the pinyon-juniper area, and
was recorded from the upper limit of this association, near Jackson
Lake, at 6000 feet, to the lower limit of the association at the mouth
of Graham Canyon at roughly 4000 feet elevation.

Although in the juniper belt _truei_ often occurs on common ground
with _Peromyscus maniculatus sonoriensis_, the habitat preferences of
these animals are generally complementary. Where the mice occur
together, traps set in a variety of locations caught _Peromyscus
maniculatus_, but typically traps set amid the brush or on the open
ground away from the junipers were productive. On the contrary _truei_
was invariably trapped quite near the junipers and often in association
with the large nests of _Neotoma fuscipes simplex_. In fact traps set
right on the beds of litter beneath the junipers were most likely to
catch _truei_. Records kept of trapping localities show that _truei_ was
without exception trapped within twenty feet of some treelike shelter
such as junipers, pinyons, Joshua tree or scrub oaks. Thus _Peromyscus
maniculatus_ occupies the open stretches between the trees, while
_truei_ inhabits the ground beneath and immediately adjacent to the
trees. In Nevada the piñon mouse prefers rocky areas (Hall, 1946:520).
In the San Gabriel Mountains this mouse does not seem to have this
predilection.

In the juniper belt _truei_ was second to _Dipodomys panamintinus_ in
point of numbers. In the course of 500 trap-nights in the juniper belt
twenty-two _truei_ were taken with thirty-six _Dipodomys_.

I consider my series of _Peromyscus truei_ from the desert slope of the
San Gabriels to represent the subspecies _montipinoris_. The series is
closely comparable to specimens of the subspecies _montipinoris_ in the
California Museum of Vertebrate Zoology from the Mount Pinos area, but
differs from specimens of the race _chlorus_ from the San Bernardino
Mountains in certain diagnostic characteristics. In his recent paper on
_Peromyscus truei_, Hoffmeister (1951) considered the populations of
this species in the San Gabriels to be of the race _chlorus_.
Hoffmeister had only one specimen available from the San Gabriel
Mountains (Lytle Creek, on the Pacific slope) which was intermediate
between _montipinoris_ and _chlorus_, but on the basis of cranial
measurements it was referred to the race _chlorus_. Specimens of
_Peromyscus truei_ from the eastern end of the desert slope of the San
Gabriel Mountains and the Cajon Pass area would probably demonstrate
that the race _montipinoris_, which occupies the desert slope of the San
Gabriels, intergrades with the race _chlorus_, which occurs in the San
Bernardino Range immediately to the east, in the Cajon Pass area.
Although _montipinoris_ occurs on the desert slope of the San Gabriels,
_chlorus_ may occur on the Pacific slope. I took no specimens of the
piñon mouse on the Pacific slope of the San Gabriel Mountains.

In December, 1948, many small juveniles were taken in the juniper
belt, and on October 15, 1951, two females trapped at the head of
Grandview Canyon had embryos: one three and the other four. On November
13, 1951, a partially gray-pelaged subadult female was trapped which had
recently suckled young.

_Specimens examined._--Total, 17, all in Illinois Museum of
Natural History, distributed as follows: Los Angeles County:
Mescal Canyon, 4500 ft., 8 mi. SE Llano, 11; Mescal Canyon, 4300
ft., 2; 6 mi. SE Valyermo, 5100 ft., 1; Grandview Canyon, 6 mi.
SE Valyermo, 5100 ft., 1. San Bernardino County: 1 mi. W Cajon,
3200 ft., 2.

=Onychomys torridus pulcher= Elliot

Southern Grasshopper Mouse

Grasshopper mice seemed to be partial to the more sandy parts of the
Joshua tree flats where the mice were trapped regularly but not
abundantly. This mouse inhabited the barren sandy channels of Mescal
Wash but was rare on the adjacent juniper-clad benches. In the arid,
sandy washes this typical desert rodent penetrated the high
pinyon-juniper association.

Wherever grasshopper mice occurred they were outnumbered by most of the
other rodent species. For example, on November 26, 1949, below Graham
Canyon, 100 snap traps yielded 10 _Dipodomys panamintinus mohavensis_, 2
_Dipodomys merriami merriami_, 4 _Peromyscus maniculatus sonoriensis_,
and 3 _Onychomys torridus pulcher_.

Where abandoned kangaroo rat burrows were common in the Joshua tree belt
these burrows were used as retreats by _Onychomys_. Some traps set at
the entrances to old burrows caught grasshopper mice.

_Specimens examined._--Total, 7, distributed as follows: Los
Angeles County: 8 mi. E and 3 mi. S Llano, 3500 ft., 1; Mescal
Wash, 4200 ft., 5 (3 PC); 2 mi. S Valyermo, 4600 ft., 1 (PC).

=Neotoma lepida intermedia= Rhoads

Desert Woodrat

This species was on the Pacific face of the Mountains from 1600 feet
elevation in the coastal sage belt, to 4800 feet elevation in open
groves of big cone-spruce and scrub oak of the chaparral association.

The local distribution of this woodrat is determined by suitable nesting
sites. Although taken in different types of vegetation, _lepida_,
without exception, was associated with rocky areas or areas supporting
patches of prickly-pear cactus. In the channels of San Antonio Wash,
_lepida_ was commonly associated with jumbles of boulders and
boulder-dotted cut banks. There the vegetation is sparse, and the rats
dwell among the rocks; only their droppings and faint trails indicate
their presence. Among boulders _lepida_ builds only small houses of
sticks and debris, and even these only occasionally. The effect of the
prickly-pear cactus on the distribution of _lepida_ in the sageland is
striking; trap lines there yielded no woodrats where extensive rock
piles and patches of prickly-pear were absent, but many rats were taken
where patches of prickly-pear are plentiful. On an acre supporting
coastal sagebrush at the mouth of San Antonio Canyon, at 1800 feet
elevation, there were fourteen patches of prickly-pear, each covering at
least thirty square feet. In these patches there were thirteen occupied
woodrat nests. Only one patch lacked an occupied nest, and this one
contained the remains of an old nest. On this acre there were at least
thirteen individuals. In the sagebrush belt only an occasional large
patch of cactus lacks a woodrat house occupied by _lepida_. Seemingly
_Neotoma fuscipes_ does not build houses in patches of prickly-pear.

Most of the houses built by _Neotoma lepida_ are small and simple as
compared to those of _Neotoma fuscipes_, and often in rocky areas no
nests are in evidence. The most elaborate nests are built among the pads
and spines of the prickly-pear and under laurel sumac or other large
shrubs growing near washes. One of three houses examined at the mouth of
San Antonio Canyon was on sandy ground in a patch of _Opuntia_ measuring
approximately 11 x 14 feet. The house was 14 inches high and 41 x 37
inches at the base. It was built around the main stem of the
prickly-pear and a rock about 10 inches in diameter. The house was
constructed of sticks of coastal sagebrush and buckwheat, and was dotted
with dissected fruits and flowers of the prickly-pear. The main chamber
was arched over by the main stem of the prickly-pear and was roughly 12
x 19 inches, inside dimensions, being reached through two three-inch
openings, one on the east side of the chamber and one on the north side
of the chamber. Two cup-shaped nests were inside the chamber, these
being constructed mostly of grasses, and each resembling a well
constructed bird nest 4 inches in diameter. The grass nests were free of
feces, but feces were piled up against the west side of the chamber with
many snail shells and dissected fruits and flowers of prickly-pear.
Thirty-five inches from the main chamber was a third grass nest on the
ground beneath a cluster of cactus pads. Next to this there was a blind
burrow about eight inches long, and one and three-quarters inches in
diameter. No burrow led to the main chamber, in this or in either of the
other houses, but all had at least one short blind burrow beneath the
house.

At many houses there were one to three grass nests outside the house on
the ground, within four feet of the house. From each nest a well worn
path lead to the house. Traps set in these nests invariably caught
woodrats.

The many prickly-pear fruits and snail shells in and around the houses
of _lepida_ probably were remnants of food. So many of the rodents
caught in traps near woodrat nests were partly eaten--usually the brains
were taken--that I suspect the woodrats of eating their relatives. The
heads of many composite annuals were piled near woodrat nests.

Immature individuals were taken in September, October, and early
November, and on September 26, 1951, a lactating female was trapped near
Palmer Canyon.

An old female bobcat trapped in Thompson Canyon had masses of cactus
thorns beneath her skin, especially about the forelegs. These thorns
were probably received while she was foraging in growths of prickly-pear
for woodrats. The other bobcats from San Antonio Wash also had
accumulations of thorns under the skin of the forelegs. Fragments of the
skulls of _Neotoma lepida_ were recovered from horned owl pellets and
coyote feces.

_Specimens examined._--Total, 7, distributed as follows: Los
Angeles County: San Antonio Canyon, 4500 ft., 2; San Antonio
Wash, 1800 ft., 5 (2 PC).

=Neotoma lepida lepida= Thomas

Desert Woodrat

These woodrats were present in rocky situations along the desert slope
from the lower edge of the juniper belt down into the desert. Specimens
were taken in piles of boulders in Mescal Wash, and amid rock
outcroppings on the steep, barren, south slopes at the base of Grandview
Canyon, whereas none was found on the juniper-clad benches.

This woodrat built no nests in rocky areas; however, in the Joshua tree
belt _N. l. lepida_ often built small nests at the bases of large
standing or prostrate Joshua trees. There sticks from creosote bushes,
along with cow dung and small stones were favorite building materials.
Judging from the large number of unused woodrat nests in the Joshua tree
flats it seemed that this rat was formerly far more common than it was
in the period of this study.

_Specimens examined._--Total, 9, distributed as follows: Los
Angeles County: 6 mi. E and 1 mi. S Llano, 3500 ft., 4; Mescal
Wash, 4200 ft., 5 (3PC).

=Neotoma fuscipes macrotis= Thomas

Dusky-footed Woodrat

This subspecies was widely distributed along the coastal slope of the
mountains from the coastal sage belt, at roughly 1600 feet, up to 6500
feet at the lower edge of the yellow pine forest and was most common in
the chaparral association.

In the coastal sage belt these woodrats are restricted to wash areas
where large chaparral plants such as lemonadeberry and laurel sumac are
used as nesting sites. In San Antonio Wash the occasional large juniper
trees almost invariably harbor the nests of _fuscipes_. The general
absence of suitable nesting sites in the sage belt probably limits the
spread of _fuscipes_ in this area.

In the upper part of the chaparral belt in talus these woodrats live
beneath the angular boulders and build no visible houses. Several areas
of talus occupied by woodrats were examined carefully and no sign of
houses was noted.

Two juveniles were found in the stomach of a rattlesnake (_Crotalus
viridis helleri_) killed in May, 1948, at the mouth of Evey Canyon.
Remains of woodrats were found in feces of the coyote and gray fox.

Lactating females of this species were taken on March 16, and October 2,
1951.

_Specimens examined._--Total, 4, distributed as follows: San
Bernardino County: Icehouse Canyon, 5500 ft., 2. Los Angeles
County: San Antonio Canyon, 2800 ft., 2.

=Neotoma fuscipes simplex= True

Dusky-footed Woodrat

These rats were recorded from the yellow pine forests on Blue Ridge, at
8100 feet, down to the lower edge of the juniper belt, at 3800 feet.
Their presence there as elsewhere was determined by the occurrence of
adequate cover. On Blue Ridge they were taken in and near patches of
snowbrush, currant, and choke cherry, and one was taken beneath a pile
of logs where no nest was in evidence.

The thickets of choke cherry in hollows on Blue Ridge were favored
house-building sites of woodrats. Among the tangle of branches large
nests were built, and in September, 1951, the remains of choke cherry
fruit and gnawings on the limbs of these plants indicated that woodrats
were active throughout these extensive patches of brush.

In the pinyon-juniper association most of the large plants were used
as nesting sites, but scrub oak, seemed to be especially preferred.
Because it often grew in a twisted irregular form with the foliage
nearly reaching the ground, the oak offered good shelter for the woodrat
nests. In an acre of scrub oak and mountain mahogany brush one-half mile
north of Jackson Lake, at 6100 feet, thirteen occupied woodrat nests
were found. In the juniper belt, houses were of more irregular
occurrence, and were always beneath juniper trees, usually beneath the
largest and most widely spreading individuals.

Those specimens from Blue Ridge, on the crest of the San Gabriels, are
intergrades between the coastal race _macrotis_ and _simplex_ of the
desert slope. Although specimens vary widely in color, comparison with
series of these two subspecies in the California Museum of Vertebrate
Zoology indicates that all specimens from the desert slope of the San
Gabriels are referable to the race _simplex_. Two specimens of this
species from the granite talus above the base of Icehouse Canyon at 5500
feet on the Pacific slope, grade strongly toward _simplex_. Hooper
(1938:231) mentions that specimens of this species taken along the San
Gabriel and San Bernardino ranges may be intermediate between _simplex_
and _macrotis_.

At the head of Grandview Canyon, tracks indicated that a coyote had
foraged for about one half mile along the edge of a tract of dense oak
and pinyon growth. It seemed as if the animal had been foraging for
woodrats. A gray fox trapped near Graham Canyon, in the juniper belt,
had in its stomach the remains of a freshly killed adult woodrat. The
remains of an adult woodrat were found in the stomach of a rattlesnake
(_Crotalus viridis helleri_) obtained on the desert slope of the
mountains.

_Specimens examined._--Total, 6, distributed as follows: Los
Angeles County: 6 mi. E Valyermo, 5600 ft., 1; 1 mi. E Big
Pines, 6600 ft., 2; 1 mi. S and 3 mi. W Big Pines, 6000 ft., 1;
1 mi. S and 2 mi. E Big Pines, 8100 ft., 2.

=Microtus californicus sanctidiegi= R. Kellogg

California Meadow Mouse

Owing to the paucity of extensive areas of grassland in the San
Gabriels, this is one of the least common rodents of the area. It
inhabits, however, even small patches of grassland up to 4000 feet
elevation on the Pacific slope, and is locally plentiful. For example, a
small patch of grassland amid the chaparral at the mouth of Palmer
Canyon supported many _Microtus_, and in San Antonio Canyon at about
3000 feet elevation meadow mice were found amid boulders and yuccas in a
small grassy area near the stream.

_Specimens examined._--Total, 3, distributed as follows: Los
Angeles County: San Antonio Canyon, 2800 ft., 1; Palmer Canyon,
2100 ft., 1; 4 mi. N Claremont, 1800 ft., 1.

Family URSIDAE

=Ursus americanus californiensis= J. Miller

Black Bear

Eleven black bears were introduced into the San Gabriel Mountains "near
Crystal Lake" in November 1933 from the Sierra Nevada (Burghduff,
1935:83). I do not know whether or not there have been subsequent
introductions. There are still bears present in the higher parts of the
mountains, especially north of the study area, where they seem to be
maintaining their numbers. The grizzly bear that formerly occurred in
the San Gabriel Mountains was exterminated there some years before the
black bear was introduced.

Family PROCYONIDAE

=Bassariscus astutus octavus= Hall

Ring-tailed Cat

Large sections of the San Gabriel Mountains are uninhabited by this
species, while locally, in the chaparral belt near water, ring-tails are
common. Many reports of ring-tails were received from owners of cabins
and homes who reside in the canyons at the Pacific base of the
mountains. Because of the distinctive appearance of this animal it is
likely that many of these reports were accurate. The reports testified
to the presence of ring-tails in San Gabriel Canyon, Dalton Canyon,
Palmer Canyon and San Antonio Canyon. Hall (1927:41) lists specimens
from San Antonio Canyon. Kenneth Hill of Upland told me that ring-tailed
cats often have been trapped above that town near citrus nurseries that
are regularly irrigated. This species probably is not present on the
desert slope of the range.

The only specimen that I took was a female weighing one pound and
fourteen ounces. It was trapped on March 24, 1951, among granite
boulders, beneath scrub oak and bay trees, near the mouth of Icehouse
Canyon, at 5500 feet elevation.

=Procyon lotor psora= Gray

Raccoon

The raccoon was one of the most common carnivores in the San Gabriels
and was found on both slopes of the range. Tracks were noted and one old
male was trapped at the base of the Pacific slope foothills at 1900 feet
elevation, and raccoons were captured at several localities from this
point up to 5500 feet in San Antonio Canyon. They were noted on Blue
Ridge at about 8000 feet elevation foraging around the camp grounds. On
the desert slope they occurred down to the lower edge of the
pinyon-juniper belt, for example near the mouth of Sheep Creek Canyon.

Sign of raccoons was most often found near water; tracks, however,
indicated that these animals, along with other carnivores, used fire
roads for traveling through the chaparral. In a small draw one-half mile
east of the mouth of Thompson Canyon two raccoons were trapped although
the only water was a series of small, disconnected seepage pools beneath
the valley oaks.

A raccoon freed from a small steel trap in San Antonio Canyon concealed
itself in an unusual but extremely effective manner. When released the
coon splashed up the middle of the small creek nearby to a place where
some dead alders had fallen over and shaded the water--here the animal
squatted down in the stream. The raccoon was mostly submerged, its tail
was floating, and its back and the top of its head and snout were above
water. With most of its body under water, and with the maze of alder
logs above casting a broken pattern of light and shade, it was well
hidden. When closely pressed the raccoon hid in the same manner several
times before it disappeared up a rocky draw into the scrub oak brush.

In the autumn of 1951, raccoons fed on grapes at the Sycamore Valley
Ranch one mile south of Devore. The one specimen (P. C.) saved, an old
male from 1/2 mi. W Palmer Canyon, had remains of beetles in its stomach
and weighed slightly more than 13 pounds.

Family MUSTELIDAE

=Mustela frenata latirostra= Hall

Long-tailed Weasel

Several weasels were found dead on roads in the coastal sage belt near
San Antonio and Lytle canyons.

=Taxidea taxus neglecta= Mearns

Badger

I found no sign of badgers on the Pacific slope of the range, but James
Wolfort, employed by the state Fish and Game Commission to trap coyotes,
reported that in 1948 he trapped also several badgers at the coastal
foot of the range in the San Fernando Valley area which is west of the
study area.

=Taxidea taxus berlandieri= Baird

Badger

Many old badger diggings were found in the Joshua tree woodland and
pinyon-juniper associations of the desert slope, but none of the animals
was observed nor were specimens secured. Mr. E. A. Eberle who has
trapped for many winters in the vicinity of Mescal Canyon stated that he
caught badgers occasionally.

I examined the skin of a badger taken at Llano which showed the
characteristic paleness of the desert subspecies _berlandieri_.

=Mephitis mephitis holzneri= Mearns

Striped Skunk

The populations of striped skunks in the San Gabriels center around
cultivated land at the Pacific foot of the range. Citrus groves, grape
vineyards, and areas once cleared by man are preferred to coastal
sagebrush flats. The cultivated areas now probably support many more
skunks than were there under original conditions. I have many sight
records of striped skunks which I obtained while driving through the
citrus groves at night. Only once was the striped skunk noted in the
chaparral; all the other records were from the coastal sagebrush belt.

In addition to insects and small mammals, grapes are eaten regularly by
skunks in vineyards, and the fruit of the prickly-pear cactus is often
eaten. Near the mouth of Thompson Canyon feces examined in October 1948,
contained almost exclusively the remains of prickly-pear fruit.

A male taken one-half mile south of Devore weighed five pounds and four
ounces.

_Specimens examined_, 2: San Bernardino County: 1/2 mi. S
Devore, 2200 ft., 1. Los Angeles County: 3 mi. N Claremont, 1500
ft., 1 (PC).

=Spilogale gracilis microrhina= Hall

Spotted Skunk

Spotted skunks are common locally in the coastal sage scrub association
and lower chaparral association on the coastal face of the mountains,
mainly between 1000 and 4000 feet elevation; but they have been reported
from Icehouse Canyon at 5000 feet, and I took one above the mouth of
this canyon at 5500 feet elevation. A few spotted skunks may inhabit the
lower desert slope of the mountains; here feces thought to be those of
spotted skunks have been found, and a bobcat trapped near the head of
Grandview Canyon smelled strongly of skunk.

The spotted skunk usually was in rocky habitats. In the sage flats, sign
(mostly feces and tracks) usually was near rock piles and around human
developments such as rock walls, old outbuildings and houses. Specimens
taken in the chaparral were trapped near granite outcroppings.

In the autumn of 1950, at my house near the mouth of Palmer Canyon, a
family of spotted skunks lived under the floors. Night after night they
scratched under the floor and chattered in high-pitched rasping notes,
and on several evenings one walked complacently into the living room. It
finally became necessary to trap and deport most of these skunks. In
all, nine skunks were trapped; these probably represented more than the
original residents. One male was descented and allowed to remain. It
spent most of the daylight hours asleep in an old shower room where the
many gaps between the rock work and the boards allowed him entrance.
Through no special efforts on our part he became tame enough to climb
over us in order to get food left on the kitchen sink, and he would eat
calmly while we sat only inches away from him.

Feces from sage areas contained mostly remains of insects and small
rodents whereas many samples of feces from chaparral areas contained, in
addition, shells of snails. Feces examined represent all months of the
year.

_Specimens examined._--Los Angeles County: mouth of San Antonio
Canyon, 2 (PC).

Family CANIDAE

=Canis latrans ochropus= Eschscholtz

Coyote

Coyotes inhabit the sagebrush flats and foothills up to at least 4000
feet all along the Pacific base of the San Gabriels. This species seems
most common at the foot of the range where large dry washes prevent
man from occupying the land immediately adjacent to the foothills, and
are the dominant carnivores of the coastal sage belt. Repeated
observations have indicated that although many individuals range into
the higher foothills they seldom are found deep in the major canyons or
chaparral slopes. Coyotes rarely occur at 3000 or 4000 feet in San
Antonio Canyon where it cuts into the realm of heavy chaparral; yet on
steep foothill slopes and ridges, which are adjacent to the flat land,
these animals range up to at least 4000 feet. Being hunters primarily of
rather open land many coyotes go into the foothills only to find daytime
refuge, traveling down dirt roads, ridges, and firebreaks, to forage at
night in the sage flats. Coyote feces from the foothills, at about 3500
feet, contained predominantly the remains of such food items as
cottontails, chickens, and jack rabbits. These animals could have been
found only in the flats. This is additional evidence that coyotes do the
major part of their hunting at the base of the range.

Observations of coyote tracks and trapping records have shown that these
animals hunt mostly in the more open parts of the sage flats. Coyotes
frequent areas of scattered brush, sandy areas, wash channels, and old
roads, and seemingly shun dense brush. Many coyotes actually hunt for
rabbits in the citrus groves near the foothills. On several evenings I
traced their howling to orange groves, and Mr. Kenneth Hill of Upland
told me of often seeing coyotes in his orange groves at night.

The forage beats of several coyotes were discovered in connection with
trapping specimens of these animals. In January, 1952, two coyotes,
probably a mated pair, traveled nightly from the slopes immediately west
of Evey Canyon, at about 3100 feet, down into the sagebrush adjacent to
the west side of San Antonio Wash, at about 1700 feet elevation. The
route led down open ridges, then for about one half mile across a level,
cultivated plateau, and then swung over the eroded banks near the
lowermost point of the plateau onto the level sage flats. The distance
covered by this route from the foothills down to the flats was somewhat
more than a mile, with about a 1400 foot difference in elevation between
the daytime retreat and the nocturnal forage area. Another route,
seemingly used by only one coyote, was somewhat longer. This animal
followed fire breaks and ridges from above Thompson Canyon down onto a
fire road, and then into the lower end of Palmer Canyon where it entered
the flats. This route covered about three miles in coming from the
foothills to the flats. Feces of this coyote often contained the
remains of white leghorn chickens which had been found at a refuse pile
near several chicken ranches one-half mile from the base of Palmer
Canyon.

Although no definite idea could be gained of the population density of
coyotes in the area, it was clear that in certain localities they were,
as carnivores go, abundant. After one large male was obtained in the
flats at the base of Cobal Canyon, at least two other individuals were
heard howling in this immediate area, and their tracks were noted
repeatedly on dirt roads. One night early in January, 1952, immediately
west of the head of San Antonio Wash, the voices of six coyotes could be
picked out separately from a chorus of coyote howls which came from
several different directions in the wash.

Many field examinations of coyote feces left the impression that
chickens and lagomorphs made up the bulk of the coyote's food on the
coastal slope. To check this a study of 39 sets of scats collected at
various localities on the coastal slope was made in the laboratory, the
results being shown in Table 10. Remains of one of the three species of
rabbits, cottontails, jack rabbits, or brush rabbits, occurred in 72 per
cent of the feces examined. Cottontails, it will be noted, were preyed
upon more heavily than any other wild species, remains of this form
being found in 33 per cent of the feces. The prevalence of chicken
remains in coyote feces does not imply that these animals were killed by
the coyotes. All of the chickens could have been found dead in the
refuse piles of the many chicken ranches. In addition, the chickens were
raised in wire cages above the ground where they were nearly
invulnerable to predation. That coyotes may at times kill deer in this
area was suggested by the finding of tracks in the sand in San Antonio
Wash which clearly indicated that a deer had been closely pursued by a
coyote. The tracks were lost in a stretch of brush so the outcome of the
chase could not be determined. Near the mouth of Lytle Creek Canyon, in
November, 1951, coyote feces contained mostly remains of grapes from
nearby vineyards. Also, above Cucamonga, coyotes were found to be
feeding heavily on grapes. This must be a rather unsuitable form of
nourishment for coyotes, for many of the grapes in the feces appeared
nearly unaltered despite their trip through the alimentary canal.

TABLE 10.--RESULTS OF EXAMINATIONS OF THIRTY-NINE SETS OF COYOTE FECES
FROM THE PACIFIC SLOPE OF THE SAN GABRIEL MOUNTAINS. FECES WERE
DEPOSITED IN AUTUMN AND WINTER (SEPTEMBER TO FEBRUARY).

===================================================================
| Number of |
| sets of feces | Percentages
Food item | which contained | of occurrence[A]
| food item |
------------------------------+-----------------+------------------
chicken | 18 | 46.2
------------------------------+-----------------+------------------
Sylvilagus audubonii | 13 | 33.3
------------------------------+-----------------+------------------
Lepus californicus | 10 | 25.6
------------------------------+-----------------+------------------
Sylvilagus bachmani | 5 | 12.8
------------------------------+-----------------+------------------
Odocoileus hemionus | 5 | 12.8
------------------------------+-----------------+------------------
rodents (unidentified) | 5 | 12.8
------------------------------+-----------------+------------------
Dipodomys agilis | 4 | 10.3
------------------------------+-----------------+------------------
Neotoma species | 3 | 7.7
------------------------------+-----------------+------------------
Mephitis mephitis | 3 | 7.7
------------------------------+-----------------+------------------
Carrion beetle | 2 | 5.1
------------------------------+-----------------+------------------
passerine bird | 1 | 2.67
------------------------------+-----------------+------------------
bot fly larva | 1 | 2.67
------------------------------+-----------------+------------------
snail shell | 1 | 2.67
------------------------------+-----------------+------------------
scorpion | 1 | 2.67
------------------------------+-----------------+------------------
Jerusalem cricket | 1 | 2.67
------------------------------+-----------------+------------------
sheep hair | 1 | 2.67
------------------------------+-----------------+------------------
Lynx rufus | 1 | 2.67
------------------------------+-----------------+------------------
Kitten of wildcat or housecat | 1 | 2.67
------------------------------+-----------------+------------------
Lophortyx californica | 1 | 2.67
------------------------------+-----------------+------------------
grapes | 1 | 2.67
------------------------------+-----------------+------------------
grass | 1 | 2.67
------------------------------+-----------------+------------------

[Footnote A: This is an expression, in percentage, of the number of sets
of feces which contained the particular food item out of the total of
thirty-nine sets examined.]

The six coyotes taken on the Pacific slope are fairly uniform in
coloration; the occurrence of white tipping on the tails of most of the
specimens, instead of the usual solid black tip, is notable. Three
skins, those of a male and two females, have patches of white hairs at
the tips of the tails; two skins, of a male and a female, show only
scattered white hairs at the tips of the tails; and the skin of one
female has a solidly black-tipped tail. An additional female, trapped
by David Leighton in Thompson Canyon, had a large patch of white hairs
at the tip of the tail. Grinnell, Dixon, and Linsdale (1937:501) mention
that only an occasional individual (female?) has a white-tipped tail.

Weights are available for four specimens: two coyotes trapped in San
Antonio Wash, a male and a female, weighed 20.5 and 23.2 pounds
respectively; a female from the mouth of San Antonio Canyon weighed 21.6
pounds; and a large male from the mouth of Thompson Canyon weighed 29.3
pounds.

_Specimens examined._--Total, 6, distributed as follows: Los
Angeles County: Live Oak Canyon, 3000 ft., 1; mouth of San
Antonio Canyon, 2000 ft., 1; 4 mi. N Claremont, 1600 ft., 2; 4
mi. NE Claremont, 1600 ft., 1; 3 mi. NE Claremont, 1600 ft., 1.

TABLE 11.--CRANIAL MEASUREMENTS OF CANIS LATRANS OCHROPUS FROM THE
COASTAL SLOPE OF THE SAN GABRIEL MOUNTAINS.

======================================================================
| Four females | Two males
| Averages Extremes | Averages Extremes
----------------------+-----------------------+-----------------------
Condylobasal length | 180.67 174.2-183.3 | 188.35 179.2-197.5
----------------------+-----------------------+-----------------------
Palatal length | 91.57 88.0-95.0 | 97.15 91.6-102.7
----------------------+-----------------------+-----------------------
Zygomatic breadth | 90.15 88.9-92.0 | 95.60 88.8-102.5
----------------------+-----------------------+-----------------------
Interorbital breadth | 29.12 27.9-29.9 | 31.45 28.1-34.8
----------------------+-----------------------+-----------------------
Length of | |
maxillary toothrow | 85.00 80.4-89.80 | 88.00 83.4-92.6
----------------------+-----------------------+-----------------------
Length of | |
upper carnassial | 18.30 17.8-19.0 | 18.70 18.1-19.3
----------------------+-----------------------+-----------------------

=Canis latrans mearnsi= Merriam

Coyote

Coyotes are common on the desert slope of the San Gabriels below about
6000 feet elevation. They seem not, or only rarely, to penetrate the
yellow pine forest belt, but tracks have been found occasionally near
the lower edge of the forest, as at the head of Mescal Canyon. In the
more open parts of the pinyon-juniper association, sign of coyotes was
noted and they were the dominant carnivores in the juniper belt and
Joshua tree woodland.

In the upper part of the pinyon-juniper association coyotes travel and
forage in sage flats, along ridges, and in sandy draws, avoiding the
extensive patches of scrub oak and mountain mahogany, and the steep,
rocky, pinyon-covered slopes. It is apparent that the local ranges of
the coyote and the gray fox in the pinyon-juniper belt are
complementary, the gray fox keeping to the more thickly wooded or brushy
parts of the area, and the coyote staying in the relatively open
sections. Probably there is little competition for food there between
these two canids.

As evidenced by tracks, coyotes commonly traveled and hunted along
desert washes, probably because of the larger population of rodents and
rabbits there. Below Graham Canyon three fairly recently inhabited dens
of coyotes were found in the cutbanks at the edge of a dry wash in
December of 1951. The cutbanks were six to ten feet high, and the dens
were dug into the banks about three feet above the floor of the wash.

On the evening of October 20, 1948, near Desert Springs, Steven M.
Jacobs and I set out a line of fifty wooden live traps for kangaroo
rats. That night we slept about 300 yards from the middle of the line
which was roughly three quarters of a mile long. When we tended the
traps the next morning we found the tracks of a coyote over our own
tracks of the previous day, and the first trap that had seemingly held a
kangaroo rat was chewed and dragged for about fifty feet. Each trap that
had held a rodent had been turned upside down so that the door had
opened. At one point in the line where we had walked for about two
hundred yards without setting a trap the coyote had followed every twist
and turn of our trail. The animal had followed out the entire trap line
and removed approximately eight rodents from the traps, reducing our
take to one _Dipodomys_ and one _Peromyscus_.

Examinations of feces showed that in the period from 1948 to 1952, while
populations of jack rabbits were low in the Mojave Desert, the coyotes
had fed extensively on smaller mammals such as kangaroo rats, and to
some extent on fruit. By contrasting the present food habits of coyotes
on the desert and coastal slopes of the mountains support is afforded
for Errington's (1937:243) statement that predation is "a by-product of
population." On the desert slope, with low populations of rabbits, the
coyotes have turned to lesser species of prey; while on the Pacific
slope, where populations of rabbits were high, the rabbits made up the
major portion of the coyote's diet. On the desert slope, remains of the
following food items were identified from coyote feces: kangaroo rats,
mule deer, jack rabbits, passerine bird, manzanita and juniper fruit,
beetles, grapes and apples. Near Valyermo, coyote feces were composed
mostly of apples from nearby orchards. A female coyote killed below
Grandview Canyon had its stomach and intestines stuffed with apples in
large chunks. In the juniper belt, berries of juniper were often eaten
by coyotes.

The three specimens of coyotes from the desert slope are clearly
referable to the desert race _C. l. mearnsi_, both with regard to
cranial and pelage characteristics. Although I collected no specimens
from Cajon Pass or the passes at the west end of the range, it is in
these places that intergradation might be expected to occur between the
desert race _C. l. mearnsi_ and the coastal and valley subspecies _C. l.
ochropus_, as the higher parts of the San Gabriels seem to constitute a
barrier to coyotes.

A subadult female coyote taken in the Joshua tree belt near Graham
Canyon weighed 20.8 pounds.

_Specimens examined._--Los Angeles County: 6 mi. E and 2 mi. S
Llano, 3600 ft., 3 (2 PC).

=Vulpes macrotis arsipus= Elliot

Kit Fox

The kit fox barely enters the area under consideration. In the Joshua
tree belt, below about 3500 feet elevation, tracks were most often noted
in washes and on the adjacent sandy ground. The highest place where
tracks were seen was a small sandy draw below the mouth of Graham Canyon
at an altitude of roughly 3900 feet.

In the Joshua tree belt many old burrows were found but none was
occupied. I believe these foxes are returning to this area where once
they were common. In the winter of 1948 no sign of kit foxes was found,
although intensive field work was done in the Joshua tree belt in the
Mescal Canyon area. In December of 1951, in the same locality, sign was
obvious and an individual was trapped below Grandview Canyon at 3500
feet elevation. Possibly since the use of poison for carnivores has been
discontinued in this district the foxes are repopulating the area.

The one specimen taken, a sub-adult female, weighed two pounds and
fourteen ounces.

_Specimen examined._--Los Angeles Co.: 6 mi. E & 1 mi. S Llano,
3500 ft., 1.

=Urocyon cinereoargenteus californicus= Mearns

Gray Fox

The gray fox is widely distributed in the San Gabriel Mountains,
occurring on both slopes of the range wherever extensive tracts of
chaparral are present. They reach maximum abundance in the chaparral
association of the coastal slope. Individuals have been observed
occasionally at night in coastal sage areas at the Pacific foot of the
mountains; however they seem to be less common here and probably come
out of the adjacent chaparral to forage in the flats at night. Gray
foxes occur all the way up the Pacific slope into the yellow pine
woodland at 7500 feet, and from 6200 feet elevation on the desert slope
down to the upper limit of the Joshua trees as, for example, near Mescal
Canyon at 4700 feet.

On the Pacific face of the mountains the gray fox probably is the
dominant carnivore in terms of its effect on prey species, first,
because of its abundance, and second, because of its forage habits. Some
appreciation of the abundance of the gray fox may be gained from
trapping records. On a fire road at the head of Thompson Canyon, at 2500
feet, two settings of traps about one-quarter mile apart were maintained
for four nights. In this time four gray foxes were trapped. At the head
of Cow Canyon, at 4500 feet, one trap set on a deer trail caught five
gray foxes in five nights. At the end of this time fox tracks were noted
about 100 yards away from the set, and another fox was trapped about one
quarter mile away. In addition to their abundance, the forage habits of
gray foxes are such as to bring them into most habitats present in the
chaparral association. Tracks and feces indicate that foxes forage under
dense brush, on open rocky ridges, in riparian growth, on talus slopes,
and in groves of big cone-spruce and scrub oak.

Trapped foxes, if uninjured by the trap, were usually released. One fox
was released on a small trail through thick vegetation consisting mainly
of snowbrush. When freed, the fox whirled and darted through a patch of
snowbrush for about seventy-five feet, then turned and disappeared
beneath some large bay trees. Although the brush through which it ran
was dense, the fox seemed to run at full speed. The success of gray
foxes as predators in the chaparral is probably due in large measure to
their agility amid dense cover.

The three specimens from the desert slope are referable to the coastal
subspecies, _U. c. californicus_, rather than the desert subspecies, _U.
c. scottii_. In all respects they resemble foxes taken on the Pacific
slope; cranial measurements are near the maximum for the large _U. c.
californicus_, and not small as would be expected if they were grading
toward the smaller _U. c. scottii_. Floors of desert valleys north of
the San Gabriel Mountains probably isolated foxes there from _U. c.
scottii_ found in the higher ranges of the Mojave Desert. Consequently
one would expect no intergradation between the coastal and desert races
in the San Gabriel Mountains.

An old female trapped on March 18,1951, in San Antonio Canyon, had three
embryos each about 105 mm. long from rump to crown, and weighed 9.2 lbs.
The average weight of four non-pregnant females was 6.8 lbs., whereas
the average of six males was 7.5 lbs.

_Specimens examined._--Total, 11, distributed as follows: Los
Angeles County: Mescal Canyon, 4800 ft., 1; 4 mi. E Valyermo,
5200 ft., 2; Cow Canyon, 4500 ft., 2; San Antonio Canyon, 3000
ft., 1; Thompson Canyon, 2500 ft., 2 (PC); 1/2 mi. W Palmer
Canyon, 2000 ft., 3 (PC).

Family FELIDAE

=Lynx rufus californicus= Mearns

Wildcat

Wildcats range over the whole of the San Gabriel Range, with the
possible exception of the tops of the highest peaks such as Mt. San
Antonio and Mt. Baden Powell. Sign of these animals has been observed,
or specimens have been taken, from the coastal sage belt up to about
8500 feet in the yellow pine forests on Blue Ridge. The subspecies
_baileyi_ occurs on the desert slope of the range.

Wildcats are most common in the chaparral belt where they forage widely
from the ridges down into the canyons. Judging from trapping records
bobcats are not so common here as the gray fox.

Bobcats occur in the sage belt, where they are most common in the broken
country around washes and in brushy areas. Although bobcats and coyotes
occupy the same general areas here, the habitat preferences of these
animals seem to be different, with coyotes occupying the more open
country. An indication of the hunting habits of bobcats is furnished by
the occurrence of masses of prickly-pear thorns beneath the skin of the
legs, particularly the forelegs, of three specimens trapped in the sage
belt. These thorns probably were acquired while the bobcats foraged for
woodrats or cottontails in the patches of prickly-pear, which are
locally abundant in the sage belt.

On March 12, 1951, a small subadult female bobcat, trapped at 4000 feet
in San Antonio Canyon, was found dead in the trap and had numerous deep
cuts around its head and shoulders, and severe bruises on the right
shoulder. The spacing of the cuts, and the tracks around the set,
indicated that while held in the trap this animal had fought with a
second bobcat that had inflicted the fatal wounds. It seems unlikely
that the fight was caused by a male attempting to copulate with the
female held in the trap, for the female was found to be carrying an
embryo.

In Live Oak Canyon, in December, 1950, tracks and bits of fur indicated
that a bobcat had killed and eaten a gray squirrel. Remains of
cottontails were found in the stomachs of two bobcats. All six bobcats
from the Pacific slope had nematode worms in the pyloric end of the
stomach.

Two females obtained on March 12 and 19, 1951, each had one embryo
approximately one inch long (rump to crown).

The following list gives the weight of each of the specimens from the
Pacific slope of the San Gabriels.

_Specimens examined._--Total, 8, distributed as follows: Los
Angeles County: San Antonio Canyon, 4000 ft., 1; San Antonio
Canyon, 3200 ft., 1; 4 mi. N Claremont, 1900 ft., 2; Thompson
Canyon, 1800 ft., 1; 3 mi. NE Claremont, 1700 ft., 2; Little
Dalton Canyon, 1500 ft., 1 (PC).

TABLE 12.--WEIGHTS OF LYNX RUFUS CALIFORNICUS FROM THE SAN GABRIEL
MOUNTAINS.

=====================================================================
sex and age | locality | date | weight
-------------+----------------------------+----------------+---------
[Female] ad. |3 mi. NE Claremont, 1700 ft.|January 20, 1951|18.8 lbs.
-------------+----------------------------+----------------+---------
[Female] sad.|4 mi. N Claremont, 1900 ft. |March 9, 1951 |12.5 "
-------------+----------------------------+----------------+---------
[Male] ad. |Thompson Canyon, 1800 ft. |January 15, 1948|13.2 "
-------------+----------------------------+----------------+---------
[Male] sad. |4 mi. N Claremont, 1900 ft. |January 26, 1951|11.3 "
-------------+----------------------------+----------------+---------
[Male] ad. |3 mi. NE Claremont, 1700 ft.|January 27, 1951|13.8 "
-------------+----------------------------+----------------+---------
[Male] sad. |San Antonio Canyon, 4000 ft.|March 12, 1951 | 7.9 "
-------------+----------------------------+----------------+---------
[Male] sad. |San Antonio Canyon, 3200 ft.|March 17, 1951 |11.2 "
-------------+----------------------------+----------------+---------

=Lynx rufus baileyi= Merriam

Wildcat

This subspecies is widely distributed on the desert slope of the range,
and was recorded down to the lower edge of the juniper belt. Tracks were
observed on many occasions in yellow pine forest, but wildcats seemed to
be commonest in the brushy parts of the pinyon-juniper association. Two
were trapped in small draws lined with pinyons and scrub oak, and two
at the base of rocky pinyon-covered slopes. Only occasionally were
tracks noted in the lower part of the juniper belt. Bobcats are most
numerous where woodrats also reach peak abundance, suggesting that
woodrats are a major food.

The four specimens from the desert slope, although exhibiting a wide
range of variation, are all representatives of the desert race
_baileyi_. A yearling male from near the head of Grandview Canyon, at
5200 feet elevation, has the profuse black spotting of the subspecies
_californicus_, but the general pallor dorsally is characteristic of the
desert subspecies. An adult female, from 4700 feet elevation in Graham
Canyon, shows the double mid-dorsal black line and the distinct black
markings around the face characteristic of _californicus_, but is
otherwise pale with reduced black patterns on the backs of the ears. The
other two specimens, an adult male and a yearling female, are typical
examples of _baileyi_, pale, and with reduced black markings. None of
the specimens of bobcats from the coastal slope of the mountains showed
characters approaching those of _baileyi_. It seems, therefore, that
these two subspecies intergrade on the interior slope of the range.

A yearling male weighed 12 pounds, and a yearling female weighed 10.5
pounds. An old male weighed 19.6 pounds, and an adult female weighed
15.1 pounds.

Remains of deer were in two of the bobcat stomachs, and one of these
stomachs also contained jack rabbit remains. Approximately a dozen
nematodes (stomach worms) were in the stomach of one of the larger male
specimens.

_Specimens examined._--Total, 4, distributed as follows: Los
Angeles County: Mescal Canyon, 4800 ft., 1; Graham Canyon, 4700
ft., 1; Grandview Canyon, 5200 ft., 2.

=Felis concolor californica= May

Mountain Lion

Several cabin owners near the mouth of Icehouse Canyon reported seeing a
lion in that area in 1950, and others said they saw huge cat tracks in
Icehouse Canyon. State Trapper James Wolfort reported that he trapped
two lions on the coastal face of the range in 1947. Authentic reports
indicate that mountain lions occur in remote sections on both slopes of
the range, and in these areas mountain lions probably are as common as
they ever were.

Family CERVIDAE

=Odocoileus hemionus californicus= (Caton)

Mule Deer

Mule deer are common in chaparral areas on both slopes of the San
Gabriel Mountains. The animals or their tracks have been observed from
the coastal sagebrush flats up to about 9200 feet on Mount San Antonio,
and on the desert slope down to the lower limit of the juniper belt.

Deer are plentiful in the upper chaparral belt, and large bands are
often noted there in spring. These bands may form in the up-mountain
migration and reoccupation of areas which were covered by winter snows.
A band of fourteen was observed on March 17, 1951, one mile east of the
mouth of Cattle Canyon, and bands of about half a dozen individuals each
were often noted in March, 1951, at the base of Icehouse Canyon.
Cronemiller and Bartholomew (1950) gave a good account of the mule deer
in the chaparral belt of the San Gabriel Mountains.

On Blue Ridge in the fall of 1951, deer were plentiful, usually being
observed near patches of snowbrush and sage. They were seldom found in
the coniferous forests. On November 6, 1951, while tending a line of
snap traps before sunup, I startled a deer from its bed at one edge of a
several-acre patch of snowbrush. In synchrony with the noise made by
this deer's rising five other deer in various parts of the brush patch
leaped up and made off. When bedded down in these extensive brush tracts
deer are probably safe from an undetected approach, for a noiseless
approach through the brush is impossible.

Two deer skulls from the San Gabriels were examined: that of an adult
male from Evey Canyon, and that of an adult female from the mouth of
Palmer Canyon. Using as a basis for comparison the cranial measurements
for the subspecies _californicus_ and _fuliginatus_ given by Cowan
(1933:326), these skulls were subspecies _californicus_. In none of the
cranial characteristics considered did they tend toward the southern
race _fuliginatus_. A young adult male, however, which was killed by a
car near Cajon Pass on October 2, 1951, showed pelage characteristics of
_fuliginatus_. Its fresh winter pelage was dark, and had the distinct
black mid-dorsal line and the broad dorsal line on the tail mentioned by
Cowan (_ibid._) as distinguishing marks of the race _fuliginatus_. Its
cranial measurements were not taken. Judging from this limited material
the deer in the central part of the range, that is to say, in the San
Antonio Canyon region, are of the race _californicus_, while
_fuliginatus_ may penetrate the extreme eastern end of the range.

Deer hair and bones were often found in coyote feces from the sagebrush
belt. Some of these records may represent deer eaten as carrion. On
February 6, 1952, tracks across a sandy channel in San Antonio Wash
demonstrated that a deer had been closely pursued by a coyote. The deer
had leaped from a cutbank onto the sand, had whirled around in several
sharp turns, and had run into the adjacent brush. The tracks of a
running coyote followed every twist of the deer's trail. The trail was
followed into the brush where it was lost. Two bobcats trapped near
Graham Canyon on the desert slope had hair and bones of deer in their
stomachs.

_Specimens examined_, 2: Los Angeles County: Evey Canyon, 2100
ft., 1 (PC); Palmer Canyon, 1900 ft., 1 (PC).

Family BOVIDAE

=Ovis canadensis nelsoni= Merriam

Bighorn

Bands of bighorn sheep occur on some of the higher and more rugged peaks
of the San Gabriel Mountains. Although I never sighted the animals
themselves, I have seen abundant signs of their presence on the ridge
sloping west from Telegraph Peak at about 9000 feet elevation. Several
bands reportedly range in the head of San Antonio Canyon, and to the
south on Telegraph, Ontario, and Cucamonga peaks. The sheep usually stay
in the higher sections of the range, generally above about 7000 feet
elevation. According to district Ranger A. Lewis some bighorns summer in
the lower East Fork of San Gabriel Canyon. The subspecific status of the
bighorns in the San Gabriel Mountains has not been definitely
determined. Following Grinnell (1933:211) they are here referred to
_nelsoni_. If the band can be preserved without introduction of "alien"
stock, the United States Forest Service and the California Fish and Game
Commission will have registered an achievement that will be applauded by
all persons who are interested in American wildlife.

LITERATURE CITED

BENSON, S. B.

1930. Two new pocket mice, genus _Perognathus_, from the
Californias. Univ. California Publ. Zool., 32:449-454.

1949. The bat name _Myotis ruddi_ Silliman and von Bloeker, a
synonym of _Myotis volans longicrus_ (True). Jour. Mamm.,
30:48-50.

BORELL, A. E.

1937. A new method of collecting bats. Jour. Mamm., 18:478-480.

BURGHDUFF, A. E.

1935. Black bears released in southern California. California
Fish and Game, 21:83-84.

BURT, W. H.

1932. The systematic status and geographic range of the San
Gabriel pocket gopher (_Thomomys bottae neglectus_ Bailey).
Jour. Mamm., 13:369-370.

COWAN, I. MC.

1933. The mule deer of southern California and northern Lower
California as a recognizable race. Jour. Mamm., 14:326-327.

CRONEMILLER, F. P., and BARTHOLOMEW, P. S.

1950. The California mule deer in chaparral forests. California
Fish and Game, 36:343-365, 7 figs. in text.

ERRINGTON, P. L.

1937. What is the meaning of predation? Smithsonian Inst., Ann.
Rept., for 1936:243-252.

GRINNELL, H. W.

1918. A synopsis of the bats of California. Univ. California
Publ. Zool., 17:223-404, pls. 14-24, 24 figs. in text.

GRINNELL, J.

1908. The biota of the San Bernardino Mountains. Univ. California
Publ. Zool., 5:1-170, 24 pls.

1933. Review of the Recent mammal fauna of California. Univ.
California Publ. Zool., 40:71-234.

GRINNELL, J., DIXON, J., and LINSDALE, J. M.

1937. Fur-bearing mammals of California.... Univ. California
Press, 2 vols., xii + 375 pp., pls. 1-7, figs. 1-138, xiv +
377-777 pp., pls. 8-13, figs. 139-345.

GRINNELL, J., and SWARTH, H. S.

1913. An account of the birds and mammals of the San Jacinto Area
of southern California with remarks upon the behavior of
geographic races on the margins of their habitats. Univ.
California Publ. Zool., 10:197-406, pls. 6-10, 3 figs. in
text.

HALL, E. R.

1926. Systematic notes on the subspecies of _Bassariscus astutus_
with description of one new form from California. Univ.
California Publ. Zool., 30:39-50, pls. 2 and 3.

1946. Mammals of Nevada. Univ. California Press, Berkeley, xi +
710, frontispiece, colored, 11 pls., 485 figs. in text,
unnumbered silhouettes.

HOOPER, E. T.

1938. Geographical variation in woodrats of the species _Neotoma
fuscipes_. Univ. California Publ. Zool., 42:213-246, pls.
7-8, 2 figs. in text.

JACKSON, H. H. T.

1928. A taxonomic review of the American long-tailed shrews. N.
Amer. Fauna, 51:1-238, pls. 1-13, 24 figs. in text.

MERRIAM, C. H.

1898. Life zones and crop zones of the United States. U. S. Dept.
Agr. Bur. Biol. Surv., Bull. 10:1-79, 1 map.

MUNZ, P. A., and KECK, D. D.

1949. California plant communities. Al Aliso, 2:87-105, 4 pls.

OAKESHOTT, G. B.

1937. Geology and mineral deposits of the western San Gabriel
Mountains, Los Angeles County. California Jour. Mines and
Geol., 33:215-249, 1 pl., 7 figs. in text.

PEQUEGNAT, W. E.

1951. The biota of the Santa Ana Mountains. Jour. Entomol. and
Zool., 42:1-84.

SANBORN, C. C.

1932. The bats of the genus _Eumops_. Jour. Mamm., 13:347-357.

VAUGHAN, T. A.

1953. Unusual concentration of hoary bats. Jour. Mamm., 34:256.

VON BLOEKER, J. C.

1932. Extensions of the ranges of pocket gophers in southern
California. Jour. Mamm., 13:76-77.

WILLETT, G.

1944. Mammals of Los Angeles County. Los Angeles County Mus. Sci.
Ser., no. 9, Zool. no. 4, 26 pls.

_Transmitted July 20, 1954._

[Illustration]

25-5184

UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Institutional libraries interested in publications exchange may obtain
this series by addressing the Exchange Librarian, University of Kansas
Library, Lawrence, Kansas. Copies for individuals, persons working in a
particular field of study, may be obtained by addressing instead the
Museum of Natural History, University of Kansas, Lawrence, Kansas. There
is no provision for sale or this series by the University Library which
meets institutional requests, or by the Museum of Natural History which
meets the requests of individuals. However, when individuals request
copies from the Museum, 25 cents should be included, for each separate
number that is 100 pages or more in length, for the purpose of defraying
the costs of wrapping and mailing.

* An asterisk designates those numbers of which the Museum's supply (not
the Library's supply) is exhausted. Numbers published to date, in this
series, are as follows:

Vol. 1. 1. The pocket gophers (Genus Thomomys) of Utah. By
Stephen D. Durrant. Pp. 1-82, 1 figure in text.
August 15, 1946.

2. The systematic status of Eumeces pluvialis Cope, and
noteworthy records of other amphibians and reptiles
from Kansas and Oklahoma. By Hobart M. Smith. Pp.
85-89. August 15, 1946. 5 3. The tadpoles of Bufo
cognatus Say. By Hobart M. Smith. Pp. 93-96, 1
figure in text. August 15, 1946.

4. Hybridization between two species of garter snakes. By
Hobart M. Smith. Pp. 97-100. August 15, 1946.

5. Selected records of reptiles and amphibians from
Kansas. By John Breukelman and Hobart M. Smith. Pp.
101-112. August 15, 1946.

6. Kyphosis and other variations in soft-shelled turtles.
By Hobart M. Smith. Pp. 117-124, 3 figures in text.
July 7, 1947.

*7. Natural history of the prairie vole (Mammalian Genus
Microtus). By E. W. Jameson, Jr. Pp. 125-151, 4
figures in text. October 6, 1947.

8. The postnatal development of two broods of great
horned owls (Bubo virginianus). By Donald F.
Hoffmeister and Henry W. Setzer. Pp. 157-173, 5
figures in text. October 6, 1947.

9. Additions to the list of the birds of Louisiana. By
George H. Lowery, Jr. Pp. 177-192. November 7, 1947.

10. A check-list of the birds of Idaho. By M. Dale Arvey.
Pp. 193-216. November 29, 1947.

11. Subspeciation in pocket gophers of Kansas. By
Bernardo Villa R. and E. Raymond Hall. Pp. 217-236, 2
figures in text. November 29, 1947.

12. A new bat (Genus Myotis) from Mexico. By Walter W.
Dalquest and E. Raymond Hall. Pp. 237-244, 6 figures
in text. December 10, 1947.

13. Tadarida femorosacca (Merriam) in Tamaulipas, Mexico.
By Walter W. Dalquest and E. Raymond Hall. Pp.
245-248, 1 figure in text. December 10, 1947.

14. A new pocket gopher (Thomomys) and a new spiny pocket
mouse (Liomys) from Michoacán, Mexico. By E. Raymond
Hall and Bernardo Villa R. Pp. 249-256, 6 figures in
text. July 26, 1948.

15. A new hylid frog from eastern Mexico. By Edward H.
Taylor. Pp. 257-264, 1 figure in text. August 16,
1948.

16. A new extinct emydid turtle from the Lower Pliocene
of Oklahoma. By Edwin C. Galbreath. Pp. 265-280, 1
plate. August 16, 1948.

17. Pliocene and Pleistocene records of fossil turtles
from western Kansas and Oklahoma. By Edwin C.
Galbreath. Pp. 281-284. August 16, 1948.

18. A new species of heteromyid rodent from the Middle
Oligocene of northeastern Colorado with remarks on
the skull. By Edwin C. Galbreath. Pp. 285-300, 2
plates. August 16, 1948.

19. Speciation in the Brazilian spiny rats (Genus
Proechimys, Family Echimyidae). By João Moojen. Pp.
301-406, 140 figures in text. December 10, 1948.

20. Three new beavers from Utah. By Stephen D. Durrant
and Harold S. Crane. Pp. 407-417, 7 figures in text.
December 24, 1948.

21. Two new meadow mice from Michoacán, Mexico. By E.
Raymond Hall. Pp. 423-427, 6 figures in text.
December 24, 1948.

22. An annotated check list of the mammals of Michoacán,
Mexico. By E. Raymond Hall and Bernardo Villa R. Pp.
431-472, 2 plates, 1 figure in text. December 27,
1949.

23. Subspeciation in the kangaroo rat, Dipodomys ordii.
By Henry W. Setzer. Pp. 473-573, 27 figures in text,
7 tables. December 27, 1949.

24. Geographic range of the hooded skunk, Mephitis
macroura, with description of a new subspecies from
Mexico. By E. Raymond Hall and Walter W. Dalquest.
Pp. 575-580, 1 figure in text. January 20, 1950.

25. Pipistrellus cinnamomeus Miller 1902 referred to the
Genus Myotis. By E. Raymond Hall and Walter W.
Dalquest. Pp. 581-590, 5 figures in text. January 20,
1950.

26. A synopsis of the American bats of the Genus
Pipistrellus. By E. Raymond Hall and Walter W.
Dalquest. Pp. 591-602, 1 figure in text. January 20,
1950.

Index. Pp. 605-638.

*Vol. 2. (Complete) Mammals of Washington. By Walter W. Dalquest.
Pp. 1-444, 140 figures in text. April 9, 1948.

Vol. 3. *1. The avifauna of Micronesia, its origin, evolution,
and distribution. By Rollin H. Baker. Pp. 1-359, 16
figures in text. June 12, 1951.

*2. A quantitative study of the nocturnal migration of
birds. By George H. Lowery, Jr. Pp. 361-472, 47
figures in text. June 29, 1951.

3. Phylogeny of the waxwings and allied birds. By M. Dale
Arvey. Pp. 473-530, 49 figures in text, 13 tables.
October 10, 1951.

4. Birds from the state of Veracruz, Mexico. By George H.
Lowery, Jr. and Walter W. Dalquest. Pp. 531-649, 7
figures in text, 2 tables. October 10, 1951.

Index. Pp. 651-681.

*Vol. 4. (Complete) American weasels. By E. Raymond Hall. Pp.
1-466, 41 plates, 31 figures in text. December 27,
1951.

Vol. 5. 1. Preliminary survey of a Paleocene faunule from the
Angels Peak area, New Mexico. By Robert W. Wilson.
Pp. 1-11, 1 figure in text. February 24, 1951.

2. Two new moles (Genus Scalopus) from Mexico and Texas.
By Rollin H. Baker. Pp. 17-24. February 28, 1951.

3. Two new pocket gophers from Wyoming and Colorado. By
E. Raymond Hall and H. Gordon Montague. Pp. 25-32.
February 28, 1951.

4. Mammals obtained by Dr. Curt von Wedel from the
barrier beach of Tamaulipas, Mexico. By E. Raymond
Hall. Pp. 33-47, 1 figure in text. October 1, 1951.

5. Comments on the taxonomy and geographic distribution
of some North American rabbits. By E. Raymond Hall
and Keith R. Kelson. Pp. 49-58. October 1, 1951.

6. Two new subspecies of Thomomys bottae from New Mexico
and Colorado. By Keith R. Kelson. Pp. 59-71, 1 figure
in text. October 1, 1951.

7. A new subspecies of Microtus montanus from Montana and
comments on Microtus canicandus Miller. By E. Raymond
Hall and Keith R. Kelson. Pp. 73-79. October 1, 1951.

8. A new pocket gopher (Genus Thomomys) from eastern
Colorado. By E. Raymond Hall. Pp. 81-85. October 1,
1951.

9. Mammals taken along the Alaskan Highway. By Rollin H.
Baker. Pp. 87-117. 1 figure in text. November 28,
1951.

*10. A synopsis of the North American Lagomorpha. By E.
Raymond Hall. Pp. 119-202. 68 figures in text.
December 15, 1951.

11. A new pocket mouse (Genus Perognathus) from Kansas.
By E. Lendell Cockrum. Pp. 203-206. December 15,
1951.

12. Mammals from Tamaulipas, Mexico. By Rollin H. Baker.
Pp. 207-218. December 15, 1951.

13. A new pocket gopher (Genus Thomomys) from Wyoming and
Colorado. By E. Raymond Hall. Pp. 219-222. December
15, 1951.

14. A new name for the Mexican red bat. By E. Raymond
Hall. Pp. 223-226. December 15, 1951.

15. Taxonomic notes on Mexican bats of the Genus
Rhogeëssa. By E. Raymond Hall. Pp. 227-232. April 10,
1952.

16. Comments on the taxonomy and geographic distribution
of some North American woodrats (Genus Neotoma). By
Keith R. Kelson. Pp. 233-242. April 10, 1952.

17. The subspecies of the Mexican red-bellied squirrel,
Sciurus aureogaster. By Keith R. Kelson. Pp. 243-250,
1 figure in text. April 10, 1952.

18. Geographic range of Peromyscus melanophrys, with
description of new subspecies. By Rollin H. Baker.
Pp. 251-258, 1 figure in text. May 10, 1952.

19. A new chipmunk (Genus Eutamias) from the Black Hills.
By John A. White. Pp. 259-262. April 10, 1952.

20. A new piñon mouse (Peromyscus truei) from Durango,
Mexico. By Robert B. Finley, Jr. Pp. 263-267. May 23,
1952.

21. An annotated checklist of Nebraskan bats. By Olin L.
Webb and J. Knox Jones, Jr. Pp. 269-279. May 31,
1952.

22. Geographic variation in red-backed mice (Genus
Clethrionomys) of the southern Rocky Mountain region.
By E. Lendell Cockrum and Kenneth L. Fitch. Pp.
281-292, 1 figure in text. November 15, 1952.

23. Comments on the taxonomy and geographic distribution
of North American microtines. By E. Raymond Hall and
E. Lendell Cockrum. Pp. 293-312. November 17, 1952.

24. The subspecific status of two Central American
sloths. By E. Raymond Hall and Keith R. Kelson. Pp.
313-317. November 21, 1952.

25. Comments on the taxonomy and geographic distribution
of some North American marsupials, insectivores, and
carnivores. By E. Raymond Hall and Keith R. Kelson.
Pp. 319-341. December 5, 1952.

26. Comments on the taxonomy and geographic distribution
of some North American rodents. By E. Raymond Hall
and Keith R. Kelson. Pp. 343-371. December 15, 1952.

27. A synopsis of the North American microtine rodents.
By E. Raymond Hall and E. Lendell Cockrum. Pp.
373-498, 149 figures in text. January 15, 1953.

28. The pocket gophers (Genus Thomomys) of Coahuila,
Mexico. By Rollin H. Baker. Pp. 499-514, 1 figure in
text. June 1, 1953.

29. Geographic distribution of the pocket mouse,
Perognathus fasciatus. By J. Knox Jones, Jr. Pp.
515-526, 7 figures in text. August 1, 1953.

30. A new subspecies of wood rat (Neotoma mexicana) from
Colorado. By Robert B. Finley, Jr. Pp. 527-534, 2
figures in text. August 15, 1953.

31. Four new pocket gophers of the genus Cratogeomys from
Jalisco, Mexico. By Robert J. Russell. Pp. 535-542.
October 15, 1953.

32. Genera and subgenera of chipmunks. By John A. White.
Pp. 543-561, 12 figures in text. December 1, 1953.

33. Taxonomy of the chipmunks, Eutamias quadrivittatus
and Eutamias umbrinus. By John A. White. Pp. 563-582,
6 figures in text. December 1, 1953.

34. Geographic distribution and taxonomy of the chipmunks
of Wyoming. By John A. White. Pp. 584-610, 3 figures
in text. December 1, 1953.

35. The baculum of the chipmunks of western North
America. By John A. White. Pp. 611-631, 19 figures in
text. December 1, 1953.

36. Pleistocene Soricidae from San Josecito Cave, Nuevo
Leon, Mexico. By James S. Findley. Pp. 633-639.
December 1, 1953.

37. Seventeen species of bats recorded from Barro
Colorado Island, Panama Canal Zone. By E. Raymond
Hall and William B. Jackson. Pp. 641-646. December 1,
1953.

Index. Pp. 647-676.

*Vol. 6. (Complete) Mammals of Utah, _taxonomy and distribution_.
By Stephen D. Durrant. Pp. 1-549, 91 figures in
text, 30 tables. August 10, 1952.

Vol. 7. *1. Mammals of Kansas. By E. Lendell Cockrum. Pp. 1-303,
73 figures in text, 37 tables. August 25, 1952.

2. Ecology of the opossum on a natural area in
northeastern Kansas. By Henry S. Fitch and Lewis L.
Sandidge. Pp. 305-338, 5 figures in text. August 24,
1953.

3. The silky pocket mice (Perognathus flavus) of Mexico.
By Rollin H. Baker. Pp. 339-347, 1 figure in text.
February 15, 1954.

4. North American jumping mice (Genus Zapus). By Philip
H. Krutzsch. Pp. 349-472, 47 figures in text, 4
tables. April 21, 1954.

5. Mammals from Southeastern Alaska. By Rollin H. Baker
and James S. Findley. Pp. 473-477. April 21, 1954.

6. Distribution of some Nebraskan Mammals. By J. Knox
Jones, Jr. Pp. 479-487. April 21, 1954.

7. Subspeciation in the montane meadow mouse, Microtus
montanus, in Wyoming and Colorado. By Sydney
Anderson. Pp. 489-506, 2 figures in text. July 23,
1954.

8. A new subspecies of bat (Myotis velifer) from
southeastern California and Arizona. By Terry A.
Vaughn. Pp. 507-512. July 23, 1954.

9. Mammals of the San Gabriel Mountains of California. By
Terry A. Vaughn. Pp. 513-582, 4 pls., 1 fig., 12
tables. November 15, 1954.

More numbers will appear in volume 7.

Vol. 8. 1. Life history and ecology of the five-lined skink,
Eumeces fasciatus. By Henry S. Fitch. Pp. 1-156, 2
pls., 26 figs. in text, 17 tables. September 1,
1954.

More numbers will appear in volume 8.

*** End of this LibraryBlog Digital Book "Mammals of the San Gabriel Mountains of California" ***

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