Part 20

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 " -------------+----------------------------+----------------+--------- ad. |Thompson Canyon, 1800 ft. |January 15, 1948|13.2 " -------------+----------------------------+----------------+--------- sad. |4 mi. N Claremont, 1900 ft. |January 26, 1951|11.3 " -------------+----------------------------+----------------+--------- ad. |3 mi. NE Claremont, 1700 ft.|January 27, 1951|13.8 " -------------+----------------------------+----------------+--------- sad. |San Antonio Canyon, 4000 ft.|March 12, 1951 | 7.9 " -------------+----------------------------+----------------+--------- 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