1936] MAMMALS OF OREGON 247 



Food habits. They feed mainly on seeds of a great variety of 

 plants, including grasses, little wild beans, borages, wild sunflowers, 

 and other composite plants, pigweeds, nettles, docks, Solanum seeds, 

 and even wild plants of the mustard family. Generally they are 

 fond of rolled oats but sometimes, when more acceptable seeds are 

 available, refuse to touch the rolled oats used for trap bait. One 

 taken by K. H. Becker at Ontario, May 17, 1917, had 960 seeds of 

 Solarium, (sp. ?) and 3 of Amaranthm in its pouches. At The Dalles. 

 Streator dug open many burrows and in each found small stores of 

 wild mustard seed, varying up to half a pint in a chamber. 



In captivity they accepted almost every kind of native seed offered 

 them, also mixed birdseed, grain, and many green plants and juicy 

 vegetables, such as cabbage, lettuce, and apple, but ate only a little, 

 evidently just for the moisture it contained. They occasionally 

 drank a little water, using their hands to dip it up or eating the 

 drops scattered on plants in their cages. In a wild state they must 

 go long periods with only the moisture obtained from vegetation. 



Economic status. Over most of their arid range these mice could 

 do little damage to crops or grazing because there is neither, but 

 locally they might gather a little seed grain along the edges of 

 fields or possibly cut some of the ripening grain for the seed-laden 

 heads. On owned and protected grazing lands they might, in con- 

 nection with many other species of rodents, place a serious check 

 on the reseeding of grasses and other forage plants and thus do 

 serious injury to the grazing industry. 



At Diamond one was taken from the stomach of a small rattle- 

 snake, and at Malheur Lake the tame grasshopper mouse killed and 

 ate as many as were put in its cage. Burrowing owl pellets are 

 generally well filled with their bones and fur, and other owls un- 

 doubtedly get many. Badgers dig out their burrows and probably 

 catch some of the occupants. As with many other rodents the 

 most economical means of control is a wise protection of their not 

 too harmful enemies, 



PEROGNATHUS PARVUS MOLLIPILOSUS COTJES 

 COUES'S POCKET MOUSE 



Perognathus mollipilosus Cones, Acad. Nat. Sci. Phila. Proc., p. 296, 1875, under 

 P. monticola. 



Type. Collected at Fort Crook, Shasta County, Calif., by John Feilner, in 

 or about 1860. 



General characters. Very little smaller than parvus; slightly more dusky 

 over back; ears noticeably larger with white or buffy spot at base more 

 conspicuous. 



Measurements. Average of three adults from type locality: Total length, 

 163 mm; tail, 88; foot, 22.3; ear (dry), 8. 



Distribution and habitat. These little mice extend northward 

 into the Klamath Valley from northeastern California but are not 

 typical, and all of the Oregon specimens might almost as well be 

 referred to parvus, as mollipilosus (fig. 55). There are specimens 

 from Tule Lake, Lost Kiver, Swan Lake Valley, and Williamson 

 Kiver, all in Klamath County. 



In habits they seem not to differ from parvus. 



