Part 11

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