150 NORTH AMERICAN FAUNA [No. 55 



are not a forest or desert species, but occur most abundantly in the 

 meadows and grassy parks and openings in or along the edges of the 

 yellow pine timber. A few often follow down the stream courses 

 into the edges of the valleys, but not far below their zone, except in 

 such cases as the colony that reaches to the Snake River at Home in 

 Baker County. 



General habits. These are typical ground squirrels, living on 

 or under the surface of the ground, generally in the open, and de- 

 pending entirely on their burrows for protection. At one moment 

 they may all be standing up like a lot of stakes in a meadow, and 

 the next all out of sight underground, a few short sharp whistles 

 or squeaks having given the warning of approaching danger. The 

 burrows are usually numerous and seem always to be close at hand. 

 In a few minutes the heads begin to pop up from one burrow and 

 another to inspect the field cautiously and when the danger has 

 passed the squirrels are soon out feeding again. In tall grass, weeds, 

 or grain they make numerous little roadways, and run from place to 

 place under safe cover. A field of alfalfa or growing grain affords 

 both food and cover, and a favorite site for new burrows. 



Hibernation. Fortunately these squirrels are inactive during 7 

 or 8 months of the year, from the middle or last of July to the first 

 or middle of March. The beginning of hibernation varies with the 

 seasons, altitude, and age of the animals; the old males become fat 

 earliest, disappear first at the lower levels, some early in July; 

 the smaller young remain out latest, but rarely beyond the 1st of 

 August. At higher elevations they are sometimes a month later in 

 entering hibernation, which probably means a month later in coming 

 out in spring. At Fort Klamath, Telford reported them still se- 

 curely buried under 14 inches of snow on March 9, 1914, but out of 

 their dens at Klamath Falls on March 12. 



Breeding habits. Six or seven young in a litter seems to be the 

 usual number, but as high as 12 and 15 have been reported (Grinnell 

 and Dixon, 1918, p. 658). The mammae of adult females are in 5 

 pairs 1 inguinal, 2 abdominal, and 2 pectoral and 10 young would 

 supposedly be the normal maximum. 



The time of breeding varies with the altitude and time of emerg- 

 ing from hibernation, the mating season beginning soon after the 

 spring awakening. The small young begin to appear out of the 

 burrows early in May, but at higher elevations many small young 

 are seen in June. By the first of July many of the young are 

 scarcely full grown and apparently some are forced to hibernate 

 before they have had time to accumulate a large supply of fat. 

 Whether these survive the winter will not be known until the species 

 is more closely studied, but it seems probable that the improvement 

 of the race depends on the survival of the fattest. 



There is scant time for one litter in the short season of activity 

 and no possibility of a second. 



Food habits. The food of these squirrels in spring and early 

 summer consists mainly of roots, bulbs, and green vegetation, in- 

 cluding grasses, clovers, and a great variety of succulent plants, 

 which fill the large stomach with juicy green pulp, mottled with 

 bright colors from many flowers, and occasionally bright berries. A 

 few bits of grasshoppers and other insects are also found in the 



