The fact that there is a special winter pelage, long, full and silky, would seem to have some meaning as an accompaniment of outdoor activity at that season. Certain it is, that in texture, the pelage of the Antelope Squirrels is quite different from that of those species which hibernate regularly and long. The latter are woolly, with much under-fur. In the fall and winter "Ammos" are uniformly very fat. This condition is probably maintained by drawing upon their food stores, which, to judge from their persistent industry earlier in the season, must be extensive. We have never taken the opportunity to dig out the burrows to see how the seeds and other foodstuffs are garnered. Interesting facts doubtless await inquiry in this direction.
The Antelope Ground Squirrel is preëminently a gatherer of seeds and fruits. The two inside-opening cheek-pouches are extensive, doubtless on this account. Rarely does an animal captured away from its burrow fail to show something in them. The following records of findings of this nature will give a good idea of the diet of the species.
In the tree-yucca belt near Mohave, March 11 to 16, 1918, many of the squirrels examined were carrying the large flat black seeds of the tree-yucca (Yucca brevifolia). These seeds were being gathered for the most part from the ground, where they had fallen from the pod-clusters overhead. But in a few cases the squirrels were seen up in the yuccas going right after the ripe pods themselves. The greatest number of these seeds being carried at one time was seventeen, this in the case of a male taken on Lee Flat, fifteen miles north of Darwin, September 28, 1917. A female taken in Walker Pass, June 27, 1911, contained in its cheek-pouches 98 shelled seeds of juniper (Juniperus californicus). A female captured at Keeler, April 28, 1912, had gathered into her cheek-pouches 178 husked seeds of the salt-grass (Distichlis spicata).
Cactus seeds are frequently gathered, and, in season, the fleshy fruits are eaten. At Vallevista, San Jacinto Valley, September 4, 1908, the squirrels were feeding chiefly on the ripe cactus "pears." The animals were well stained with the purple juice both outside and in; the whole, abdominal region was purple in some of the individuals skinned for specimens. At Cabezon, May 6, 1908, a squirrel was watched in the top of a cholla cactus eating the tender new-growth buds. The animal seemed to be able to move about without its feet being injured by the spines, but upon being shot a thorn was found sticking firmly in the roof of its mouth.
This squirrel also gathers, doubtless for food, the stems of squaw-tea (Ephedra), cut into sections, and the leaves of Sarcobatus. Immediately after rains, when the evanescent annual vegetation of the desert starts to grow, sprouting plants of certain species are also gathered.
Judging from the frequency with which Antelope Ground Squirrels get into meat-baited traps, they must have a decided taste for flesh. We have also frequently found them eating into the bodies of rodents already caught and killed in small traps, and in one case, at least, one of its own kind was the victim. Nelson (1918, p. 443) says that insects are eaten when occasion offers.
As for cultivated crops, it is not often that Antelope Ground Squirrels are to be found in settled regions, and even where they are, they do not seem to be attracted by the conditions which accompany irrigation. For example, around Cabezon in San Gorgonio Pass, in May, 1908, the
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