1936] 



MAMMALS OF OREGON 



255 



General habits. The original series of 28 specimens collected by 

 Streator were taken in orchards and gardens in October when heavy 

 rains had washed away the mounds and all external traces of the 

 gopher's work, so the burrows were located by his feet breaking 

 through into them or by thrusting a cane into the ground until a 

 burrow was penetrated. In August 1922, A. W. Moore secured 

 specimens near Canby, Forest Grove, and Hillsboro, considerably 

 extending the range of the species and learning that the pocket 

 gophers were doing damage on one of the farms. He found them 

 mainly in cultivated fields where the mounds were destroyed by 

 cultivation and the burrows were not easily located. The farmers 

 complained of their destruction of potatoes. Theo. H. Scheffer 

 found them in grain and clover fields as well as on the waste land 

 outside. 



THOMOMYS HESPERUS MERBIAM 



WEST COAST POCKET GOPHEB 

 Thomomys Hesperus Merriam, Biol. Soc. Wash. Proc. 14 : 116, 1901. 



Type. Collected at Tillamook, Oreg., by J. Ellis McLellan, November 9, 1894. 



General characters. Small, with the small pointed ears of the fuscus 

 group; color of upper parts dark rich auburn; nose and cheeks dusky; large 

 ear patches black; lower parts lighter, more ochraceous; lining of cheek 

 pouches white; feet and tip of tail whitish. About 10 percent of the indi- 

 viduals are partly or wholly black. 



Measurements. Of large old male : Total length, 222 mm ; tail, 64 ; foot, 30 ; 

 ear (dry), 6. Of adult female: 205; 60; 28; 6. (Type, immature female: 175; 

 54; 24; 6.) 



Distribution and habitat. These little richly colored pocket 

 gophers are found in the open valley spots in Tillamook County, 

 and in southern Clatsop 

 County (fig. 58). They 

 are reported from 8 or 10 

 miles east of Tillamook in 

 the Wilson Kiver Valley 

 and some 20 miles south in 

 the Nestucca River Valley. 

 Specimens have been ex- 

 amined from Tillamook, 

 Elaine, and Mount Hebo 

 in Tillamook County, 

 from Alsea in Benton 

 County, and from Elsie in 

 Clatsop County. A speci- 

 men from the top of 

 Chintimini Mountain and 

 one from Philomath, west 



FIGURE 58. Range of five forms of pocket gophers in 

 Oregon : 1, Thomomys hesperus; 2, T. monticola 

 mazama; 3, T. m. helleri; 4, T. m. nasicus; 5, T. 

 fuscus fuscus. Type localities circled. 



of Corvallis, are not fully 



typical of this species and probably have no connection with it in 



range, but can be referred to it better than to any other form. 



The range of this, as of many other species of pocket gopher, is 

 interrupted by soil and forest conditions, and each isolated colony 

 shows some slight peculiarities recognizable by the critical student 

 but not worthy of recognition by name. 



General habits. These little pocket gophers make very small bur- 

 rows and throw out small mounds of earth in the old fields, pastures. 



