University of Kansas Publications
Museum of Natural History
Volume 7, No. 9, pp. 513-582, 4 pls., 1 fg. in text, 12 tables
November 15, 1954

Mammals
of the
San Gabriel Mountains
of California

by
Terry A. Vaughan
University of Kansas
Lawrence
1954

and

Revised, Edited, with Afterword
by
Robert J. 'Roy' van de Hoek
Ballona Institute
322 Culver Boulevard, Suite 317
Los Angeles (Playa del Rey), California 90293
2011

CONTENTS
Introduction ...................................................................... ................................................................................................515
Description of the Area .................................................................. ...................................................................................516
Biotic Provinces and Ecologic Associations ............................................................................ ...........................................518
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 of 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, Cajon Wash on the east; and from the gently sloping alluvum 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 Mohave Desert at an elveation 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 SanGabriels 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 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 Collegef and the University of Illilnois Museum of Natural History are designated by PC and IM, respectively.

Figure 1. Map of the San Gabriel Mountain area showing the positions of places mentioned in the text. [Note by Robert Roy van de Hoek - this map by Terry Vaughn will be included at a future time when the opportunity to scan it arises.]

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 117o25' to longitude 118o30'. The widest part of the range is bounded by the latitude 34o7' and latitude 34o30'...............

The San Gabriel Mountains connect the Sierra Nevada with the Peninsular Ranges of southern California and Baja California. On the west the San Gabriel Mountains 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 easatward 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.............

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.............

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 sid of the range differ climatically.

BIOTIC PROVINCES AND ECOLOGIC ASSOCIATIONS
Because of the elevational extremes and attendant climatic contrasts in the San Gabriel Mountais, there is a rather wide range of environmental conditions. Four life-zones are represented: Lower Sonoran, Upper Sonoran, Transitioin, and Canadian. Within these zones certain ecologic communities can be recogized; 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.
Biotic province ..... Plant Community ..... Life -zone ..... Slope .....
Californian ... 1. Coastal Sage Scrub ... Lower Sonoran ... Pacific
Californian ... 2. Southern Oak Woodland ... Upper Sonoran ... Pacific
Californian ... 3. Chaparral ... Upper Sonoran ... Pacific
Sierran ... 4. Yellow Pine Forest and limited areas of boreal flora ... Transition Canadian ... Pacific and Desert
Nevadan ... 5. Sagebrush Scrub ... Transition Upper Sonoran ... Desert
Southern Desert ... 6. Pinyon-Juniper ... Upper Sonoran ... Desert
Southern Desert ... 7. Joshua Tree Woodland ... Lower Sonoran ... Desert

The Californian Biotic Province dominates the biotic aspect of the coastal slope of the range. Thirty-nine out of seventy-two mammals recorded from the San Gabriels are typical of this Province. The coastal sage-flats at the Pacific 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 Pine
P. ponderosa ..... Ponderosa Pine
P.contorta ..... Lodgepole Pine
Pseudotsuga macrocarpa ..... Big-cone Spruce
Abies concolor ...
Libocedrus decurrens ...
Juniperus californica
Ephedra sp.
Bromus sp.
Yucca whipplei
Yucca brevifolia
Salix sp.
Alnus rhombifolia
Castanopsis sempervirens
Quercus kelloggii
Quercus agrifiolia
Quercus dumosa
Eriogonum fasciculatum
Umbellularia californica
Tetradymia spinosa ..... Cotton-thorn
.......... (to be compiled later)

Coastal Sage Scrub Association
MAJOR PLANTS

Artemisia californica
Salvia apiana
Salvia mellifera
Eriogonum fasciculatum
Rhus integrifolia
Opuntia occidentalis
Haplopa[p]pus 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 elevatioin. 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 sagelalnd 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 base 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 thsoe 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. .......

The following list gives the results of about 500 trap nights

The prickly-pear cactus is of obvious iimportance 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 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 on the floor of canyons, and extends up the larger canyons to 4000 feet elevation or higher.........

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 corocea
Quercus dumosa
Cercocarpus betuloides
Yucca whipplei
Prunus ilicifolia
Ceanothus sp.
Arctostaphylos sp.
Umbellularia californica
This association is charateristic of the Pacific slope of the San Gabriels and extends from roughly 2000 feet elevation to 5000 or 6000 feet elevation. The ecotone between 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 assoication 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 .........

Yellow Pine Forest Association
MAJOR PLANTS

Pinus ponderosa
P. lamertiana
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 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, ..........

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 toeh desert slope ............

Dipodomys panamintus 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
Chryosthamnus nauseous
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 the mammalian dsitribution. Locally, nevertheless, the presence ...............

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 Mohave Desert from the interior base of the San Gabriels. The widely spaced Joshua trees with low bushes between, and dry washes breaking the level terrain below the mouths of canyons ar typical of this area. Field work was extended no farther down into the desert than about 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 boxthorn- and creosote-bushes is perforated by burrow systems of Dipodomys panamintus or Dipodomys merriami, and those burrows of abandoned kangaroo rats are used as retreats by Onychomys torridus and Permomyscus 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...............

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 producd no specimens except immediately adjacent to citrus groves. Pequegnat (1951) 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 the 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 pravidens Jackson
Dusky Shrew
Jackson (1928:124) recorded a specimen from Camp Baldy, 4200 feet, San Antonio Canyon.

Family SORICIDAE
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. Clarement, 1800 ft., 1 (PC).

Family SORICIDAE
Notisorex crafordi 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.

Family VESPERTILIONIDAE
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 fet 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 severall 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 grouond beneath th canopy of coniferous foliage and between the trunks of the trees. .............[to be compiled fully by Robert Roy van de Hoek in the future as time and funds allow].

Family VESPERTILIONIDAE
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........ 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 40ºF. 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 .................................

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 asa 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: .. ..........[to be compiled fully by Robert Roy van de Hoek in the future as time and funds allow]; San Antonio Canyon, 2800 ft., 5.

Family VESPERTILIONIDAE
Myotis californicus californicus (Audubon and Bachman)
California Myotis
On the Pacific face of the mountain range .. ..........[to be compiled fully by Robert Roy van de Hoek in the future as time and funds allow].

Family VESPERTILIONIDAE
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. .. ..........[to be compiled fully by Robert Roy van de Hoek in the future as time and funds allow].

Family VESPERTILIONIDAE
Pipistrellus hesperus hesperus (H. Allen)
Western Pipistrelle
This species was common in the spring and autumn of 1951.. ..........[to be compiled fully by Robert Roy van de Hoek in the future as time and funds allow].

Family VESPERTILIONIDAE
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, .. ..........[to be compiled fully by Robert Roy van de Hoek in the future as time and funds allow].

Family VESPERTILIONIDAE
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 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.

Family VESPERTILIONIDAE
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 fet 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 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 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 the 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, 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.

Family VESPERTILIONIDAE
Antrozous pallidus pacificus Merriam
Pallid Bat
The Pallid Bat is probably the most common and characteristic bat of the citrus belt.............................[to be compiled fully by Robert Roy van de Hoek in the future as time and funds allow].

Family MOLOSSIDAE
Tardarida 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. .............................[to be compiled fully by Robert Roy van de Hoek in the future as time and funds allow].

Family MOLOSSIDAE
Eumops perotis californicus (Merriam)
Mastiff Bat
H[ilda] W[ood] 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 Azuza. Probably this bat occurs locally all along the coastal base of the range. .............................[to be compiled fully by Robert Roy van de Hoek in the future as time and funds allow].

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, jackrabbits are absent from much of the coatal belt of sagebrush wehre the brush is fairly continuous, and they never were observed in the chaparral association.

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

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

Family LEPORIDAE
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 jackrabbit. 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 source 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., Mescal Canyon, 4800 ft., 3.

Family LEPORIDAE
Sylvilagus audubonii sanctidiegi (Miller)
Audubon Cottontail
Cottontails are common in the coastal sage 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 n 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 cacatus 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.

Family LEPORIDAE
Sylvilagus audubonii arizonae (J.A. Allen)
Audubon Cottontail
This subspecies was recorded on the interior slope from 5200 feet elevation, as at the ehad 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 belt...................

In the pinyon-juniper association cottontails and jack rabbits probably occur in roughly equal number, but in the Joshua tree belt cottontails seem.............

Family LEPORIDAE
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 platns form continuous thickets with little open ground. In the coastal sagebrush flats, area s supporting only scattered bushes are uninhabited by brush rabbis, while areas grown to extensive tracts of brush harbor them. When the brush rabbit's mode of escape from enemies is considered, the reason for their habitat preference becomes more clear..............................

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. Althoug coyuotes and brush rabbits often occur in the same general sections..................

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 standss with the conifers. On the interior slopes 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 thatt 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.

Family SCIURIDAE
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 land cleared by man or disturbed in the course of construction, or on severly 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......................

Family SCIURIDAE
Spermophilus beecheyi fisheri (Richardson)
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.............

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).

Family SCIURIDAE
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 bat for carnvore 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.

Family SCIURIDAE
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 neaer 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 surfacs 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.

Family SCIURIDAE
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 teh pinyon-juniper association but was also in the black oak woods on the Ball Flat fire road near Jackson Lake. Nowhere was and E. speciosus observed on common ground.
Specimens examined.-Los Angeles County: San Antonio Canyon, 5500 ft., 2 (1 PC).

Family SCIURIDAE
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 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 produced specimens of flying squirrels. Willet (1944:19) mentions that flying squirrels probably occur in the San Gabriel Mountains.

Family GEOMYIDAE
Thommys bottae pallescens Rhoads
Valley Pocket Gopher
This gopher was found below 5000 feet elevation in disturbed or open areas from Cajon Wash at Devore westward all along the coastal base of the San Gabriel Range............

Family GEOMYIDAE
Thommys 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, 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.

Family GEOMYIDAE
Thommys 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...................

Family HETEROMYIDAE
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 5000 feet. .........

Family HETEROMYIDAE
Perognathus californicus dispar Osgood
California Pocket Mouse
Mice of this subspecies were recorded from the lower chaparral association below 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 .........

Family HETEROMYIDAE
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 ..................

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

In December, 1948, panamintus was trapped consistently on nights when the temperature dropped to below 20oF. 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.

Family HETEROMYIDAE
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 wre 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.

Family HETEROMYIDAE
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.

Family HETEROMYIDAE
Dipodomys agilis agilis Gambel
Pacific Kangaroo Rat
This species was found below about 4000 feet elevation all along the coastal face of the range ad reached maximum abundance in the level tracts of coastal sage. It was oce 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 rat; remains of this rodent were often found in coyote feces, and coyotes excavated many burrow systems in large kangaroo rat coloies in the sandy ground near San Antonio Wash. The soil there is so soft that coyotes probably were often succssful 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 viirginianus 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.

Family HETEROMYIDAE
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 firsts. In Swarthout Valley perplexus was found in flats that supported basin sagebrush and Haplo[pa]ppus, 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 on opposite slopes of the San Gabriel Mountains, with integradation 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: 2mi. 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 (Barid)
Western Harvest Mouse
This specis inhabited grassy areas of the coastal sage belt, and reached a 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 adn 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 fet elevation to 3200 feet on the Pacific slope, and at 6600 feet neaer 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 Clarment, 1700 ft., 3 (PC).

Family CRICETIDAE
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 in the wash, whereas eremicus wasa 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. Total, 6, distributed as follows: Los Angeles County; Mescal Wash, 4000 ft., 10 (4 PC).

Family CRICETIDAE
Peromyscus eremicus fraterculus (Miller)
Cactus Mouse
The 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 nearly 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 feet, 1; San Antonio Wash, 1800 feet, 5 (PC).

Family CRICETIDAE
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 species is active on sub-freezing and rainy night as evidence 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 mile South and 2 miles West Big Pines, 7400 feet, 3; 1 mile South and 2 miles E Big Pines, 8200 feet, 1; 4 miles Northeast Claremont, 1900 feet, 2; San Antonio Wash, 1800 feet, 3 (PC).

Family CRICETIDAE
Onychomys torridus pulcher Elliot
Southern Grasshopper Mouse
Grasshopper mice seemed to be partial to the more sandy parts of the Joshua tree flats .....
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).

Family CRICETIDAE
Neotoma lepida intermedia Rhoads
Desert Woodrat
This species was on the Pacific face of the Mountains from 1600 ...

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

Family CRICETIDAE
Neotoma lepida lepida Thomas
Desert Woodrat
These woodrats were prsent in rocky situations.....

The woodrat built no nests in rocky areas; however, in the Joshua Tree belt ............
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).

Family CRICETIDAE
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 fet 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 .........
Specimens examined. - Total, 4, distributed as follows: San Bernardino County: Icehouse Canyon, 5500 ft., 2. Los Angeles County; San Antonio Canyon, 2800 ft., 2.

Family CRICETIDAE
Neotoma fuscipes simplex True
Dusky-footed Woodrat
These rats were recorded from the yellow pine forests on Blue Ridge, at 8100 feet,............

The thickets of choke cherry in hollows on Blue Ridge were favored house-building sites of woodrats. .........
Specimens examined. - Total, 6, distributed as follows: Los Angeles County: 6 mi. E Valyermo, 5600 ft., 1; ................

Family CRICETIDAE
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 mouse 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 unihabited by this specis, 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. 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.

Family PROCYONIDAE
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. ............ Sign of racoon was most often found near water;

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 placee where some dead alders had fallen over and shaded the water - here the animals squatted down in the stream. The racoon 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....................

In the autumn of 1951, raccoons fed on grapes at the Sycamore Valley Ranch one mile south of Devore....

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.

Family MUSTELIDAE
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.

Family MUSTELIDAE
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.

Family MUSTELIDAE
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 and 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).

Family MUSTELIDAE
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 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 they scratched under the floor and chattered in high-pitched rasping notes, and on several evening 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. Though no special efforts on our part he became tame enough to climb over us in ordere 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 ffeet all along the Pacfic base of the San Gabriels. This species seems ...........

Observations of coyote tracks ..................

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 soemwhat 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 ...........................

Specimens examined. - Total 6, distributed as follows:

Family CANIDAE
Canis latrans mearnsi Merriam
Coyote
Coyotes are common on the desert slope .....

In the upper parts of the pinyon-juniper ..................

As evidenced by tracks, coyotes common traveled .................... ................

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.

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

Family CANIDAE
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

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

Family CANIDAE
Urocyon cinereoargenteus californicus Mearns
Gray Fox

The Gray Fox is widely distributed in the San Gabriel Mountains ...............

On The Pacific face of the mountains ......................... Tracks and feces indicate that foxes .... in groves of big cone-spruce and scrub oak.

Trapped foxes, if uninjured by the trap, were usually released. ............

The three specimens from the desert slope ...........................

An old female trapped on March 18, 1951, in San Antonio Canyon ......................

Family FELIDAE
Lynx rufus californicus Mearns
Wildcat
Wildcats range over the whole of the San Gabriel range, with the exception of the tops of the higest 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 bocats and coyotes occupy the same general areas here, the habitat preferences of these animals seem to be different, wth coyotes occupying 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.

Family FELIDAE
Lynx rufus baileyi Merriam
Wildcat
This subspecies is widely distributed on the deser slope of the range, was recorded down to the lower edge of the juniper belt......... Bobcats are most numerous where woodrats also reach peak abundance, suggesting that woodrats are a major food.

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

Family FELIDAE
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 ........... Deer hair and bones were often found in coyote feces from the sagebrush belt. Some of these records may represent deer eaten as carrion............Two bobcats trapped near Graham Canyon on the desert slope had hair and bones of deer in the stomachs.

Family BOVIDAE
Ovis canadensis nelsoni Merriam
Bighorn
Band 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. Thte 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, thte 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
Burghduff, A.E. 1935. Black bears released in southern California. California Fish and Game 21: 83-84.

Grinnell, H.W. 1918. A synopsis of the bats of California. University of California Publications in Zoology, 17:223-404, plates 14-24, 24 figures in text.

Grinnell, J. 1908. The biota of the San Bernardino Mountains. University of California Publications in Zoology, 5:1-170, 24 plates.

Grinnell, J. 1933. Review of the Recent mammal fauna of California. University of California Publications in Zoology, 40:71-234.

Grinnell, J. Dixon, J. and Linsdale, J.M. 1937. Fur-bearing mammals of California . . . University of California Press, 2 volumes, xii + 375 pages, plates 1-7, figures 1-138, xiv + 377-777 pages, plates 8-13, figures 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 th margins of their habitats. University of California Publications in Zoology, 10:197-406, plates 6-10, 3 figures in text.

Willett, G. 1944. Mammals of Los Angeles County. Los Angeles County Museum Science Series, Number 9, Zoology Number 4, 26 plates.

Transmittted July 20, 1954.


AFTERWORD: REFLECTIONS, COMMENTS, AND CONCLUDING REMARKS
by
Robert Jan 'Roy' van de Hoek
Field Biologist, Naturalist, & Geographer
January 7, 2011

The San Gabriel Mountains were analyzed for the presence of 53 species of native (natural) mammals and two non-native (alien) mammals (Sierra Nevada Black Bear and Virginia Opossum) by Terry Vaughan in 1954. However, I would list the total mammal species at 56 for the San Gabriel Mountains, three more than recorded by Terry Vaughan. He did not list the Pronghorn Antelope, Grizzly Bear, and Jaguar as part of the original and genuine mammal fauna. These three mammals could be found in the San Gabriel Mountains in the 19th and early 20th Century. The Jaguar went extinct first in the 1830s-1840s. Next, the Pronghorn Antelope went extinct by the 1890s. Lastly, the Grizzly Brown Bear went extinct by the 1920s. From the 1920s onward, no mammals have gone extinct in the San Gabriel Mountains. It is not an oversight by Terry Vaughan that he did not list these three mammals as he was doing work on the extant fauna of the 1950s. He did make a comment about the Grizzly Brown Bear having been in the San Gabriel Mountains just prior to the alien introduction of the Black Bear. Terry Vaughan was trained as a mammalogist and published his research in the respected scientific journal of the University of Kansas. Ultimately, I will completely edit, compile, and provide further analysis of the very fine monograph by Terry Vaughan. It will be the 50th anniversary of his publication in 2004, so it seems a good time to plan to have his monographic report on the mammals completely ready for viewing on the internet at that time. However, at this time, I have provided you with excerpts to entice naturalists, environmentalists, visitors, scientists, and hikers to be more knowledgeable about the San Gabriel Mountains. I am motivated to do this internet web site because of my fascination and curiosity for the San Gabriel Mountains. In addition, I am motivated by my interest to draw the attention of the Sierra Club-Angeles Chapter toward a more wildlife-science and conservation biology focus regarding the San Gabriel Mountains. Consequently, I would like to acknowledge all those outings folks in the Sierra Club who love to hike and explore, as do I, in the beautiful San Gabriel Mountains.

Under discussion of "Biotic Provinces and Ecologic Associations" Terry Vaughan noted accurately that the Black Bear is an alien invasive exotic species of the San Gabriel Mountains by using the term "introduced." The Black Bear is having a negative impact on the native plants and native animals that live in the San Gabriel Mountains. These bears need to be captured alive without harm and transplanted back to the Sierra Nevada from where they originally were captured and transported in cages by truck. The only bear that is native (natural) to the San Gabriel Mountains is the Grizzly Brown Bear. Therefore, when Terry Vaughan states: "The chipmunk and the introduced black bear are the only two mammals which can be considered typical of this area" he made a mistake because the bear is non-native and is thus not to be considered in the evaluation. Therefore, only one mammal, the chipmunk, Eutamias specious specious, is genuinely characteristic of only the San Gabriel Mountains.

As to the native charismatic megafauna, the Desert Bighorn Sheep and Mountain Lion are still found in the San Gabriel Mountains. Some members of the diminutive mesofauna, such as the Raccoon and Striped Skunk have adapted behaviorally to an urban environment, which was noted by Terry Vaughan already 50 years ago.

For me, as the compiler of this fine publication of Terry Vaughan, the most important natural history discovery was that the Northern Flying Squirrel is suspected, but not substantiated, to be in the San Gabriel Mountains. Terry Vaughan was not able to capture or document a specimen. He was only able to see some ecological evidence by observing pine cones that were eaten, and using logic that the likely absence of Western Gray Squirrel in the vicinity of Big Pines meant that there must be Flying Squirrel there. He suggested that focused field work in this area may reveal the presence of the Northern Flying Squirrel. I wonder if anyone has done that field work or made any natural history observations as suggested 50 years ago by Terry Vaughan. I have it in my mind to go to the Big Pines area and see if whether I position myself there for several days to a week or more, and stay up at night to watch, whether I would be able to document the Northern Flying Squirrel. Someday, when time and money allow me that luxury, I may just do that. It seems that the well-documented presence in the San Bernardino Mountains, that they at least once upon a time, perhaps back in the Pleistocene Ice Age of 10,000 years ago, must have occurred in the San Gabriel Mountains. Did climate, Native Americans, modern Europeans, other mammal carnivore predators, or lack of food resources finally cause the local extirpation of the Northern Flying Squirrel in the San Gabriel Mountains. Or, is the Northern Flying Squirrel still extant in the San Gabriel Mountains but just escaping detection by scientist-naturalists?

I also found the discussion by Terry Vaughan regarding the Hoary Bat to be quite fascinating. Terry Vaughan also published a separate article about this bat in the Journal of Mammalogy. I wonder if his solid descriptive narrative about the Hoary Bat has any relevance to the endemic and rare Hawaiian Hoary Bat. I suspect that there is at least a tid-bit of knowledge of the natural history observations of Hoary Bat by Terry Vaughan that can be applied to the Hoary Bat of Hawaii. It is fascinating to me consider the linkage of California's San Gabriel Mountains of Los Angeles to the mountainous islands of Hawaii. It seems likely that the Hoary Bat of Hawaii flew there during a summer-autumn south-bound migration from the north while heading south to California. It does not seem likely that it was during the spring northward migration, but one cannot say. It is also of interest to consider that the first Hoary Bats of Hawaii may have been carrying seeds/spores of plants/ferns, or even insect eggs on the feet, or in the stomach. Apparently, there is only this one native bat in Hawaii and it is the Hoary Bat. The Hoary Bat is an especially narrow-winged bat and is a well known migratory species which explains how it is the most likely candidate of California's 12 (one dozen) species to colonize the Hawaiian Islands, which are about 2,300 miles (3,700 kilometers) away from North America. An interesting analogy is with a very narrow-winged bat, Leisler's Bat, which reached the Azores Islands at a distance of 930 miles (1,500 kilometers) from Europe, a long time ago.

The narrative style in the natural history accounts is quite fascinating. Such passages as regards the Western Gray Squirrel being preyed upon by the Bobcat and the Great Horned Owl are worth reading about and is good that he presented them to us. Also, the passage of the Antelope Ground Squirrel being found travelling over snow and using look-out posts of Boxthorn are excellent natural history observations.

After reading about the Antelope Ground Squirrel, I recalled my experiences with the San Joaquin Antelope Squirrel on the Carrizo Plain in San Luis Obispo county. And I think about how the Pronghorn Antelope has been recovered there, so that now there are two animals with "antelope" in their name. I now wish to share with you that the Pronghorn Antelope would also have been a part of the mammalian fauna of the desert slope of the San Gabriels, at least within the Joshua tree woodland. I wonder why Terry Vaughan did not discuss the Antelope, while he did make a brief statement that the Grizzly was in the San Gabriels.

Some specifics as to ecology are very interesting to consider from Terry Vaughan's writings. For example, under the California Meadow Mouse, he states: "Owing to the paucity of extensive areas of grassland in the San Gabriels, this is one of the least common rodents of the area." This passage can now be elaborated on as follows: Grasslands that are wet and thus meadows as indicated in the name of the mouse. These grasslands have soils to shallow and sterile to support chaparral and forest and so in turn become meadow grasslands with several kinds of wildflowers. These meadows are usually on fairly level surfaces but not exclusively. They are one of the rare wetland types of the San Gabriel Mountains. There is no way for humans to increase these meadows in size, nor should he. The meadows must remain natural with no alteration to these landscapes. More on all this discussion at a later time.

Lastly, this second edition (January 2011) adds the species accounts of Peromyscus spp. which brings this edition one step closer to completion.