250 



NORTH AMERICAN FAUNA 



[No. 55 



old doors through which to dispose of the refuse. Except for these 

 occasional visits at the surface, almost the whole life of the gopher is 

 passed in the utter darkness of its tunnels. No wonder its eyes are 

 small and weak and rarely opened, and its vibrissae, naked nose, and 

 naked tip of tail well sensitized for work in the dark. No wonder 

 its disposition is morose and savage and that each works alone for 

 most of its life. 



Breeding habits. Little is actually known of the breeding habits 

 of these rodents except that the females have 2 pairs of inguinal 

 and 2 pairs of pectoral mammae, arranged on 4 widely separated 

 mammary glands, indicating 4 to 8 young. Before they are half 

 grown the young have left the parental burrow and each is extending 

 its own tunnel and getting its own living in happy solitude that con- 

 tinues for the rest of its life except during brief mating periods. 



Food habits. Most of 

 the food of these pocket 

 gophers is obtained from 

 roots, bulbs, and tubers 

 encountered in extending 

 their tunnels, but when 

 they come to the surface 

 they usually fill the capa- 

 cious cheek pouches with 

 green vegetation gathered 

 near the opening, prefer- 

 ring clover, alfalfa, dan- 

 delions, thistles, and suc- 

 culent vegetation, but also 

 taking grasses, grains, 

 and a great variety 01 

 crops and vegetables as 

 they are encountered. 

 The roots of many plants 

 are eaten, and the bark from the woody roots of bushes and trees 

 is sometimes eaten so persistently as to destroy the plants. The 

 roots of apple and pear trees unfortunately are a favorite food, but 

 many other fruit or ornamental trees and many shrubs and vines are 

 injured by the gophers. The original name of camas rat was un- 

 doubtedly based on their fondness for the bulbs of the camas, which 

 grows in great abundance in their valley but is generally scarce 

 where the gophers are common. 



Economic status. For unknown ages these pocket gophersl have 

 been plowing the ground, burying vegetation with their mounds, 

 enriching and improving the soil for the use of man, but when the 

 white man arrives they must go for they like his crops and thrive and 

 multiply in his fields and orchards, and even in his dooryards and 

 along his streets. On Council Crest, the scenic section of Portland, 

 in 1914 their big mounds, a bushel of black earth in a place, were 

 seen on some of the best-kept lawns and again were thrown out over- 

 night on the concrete sidewalks so that pedestrians had to go around 

 or jump over them. Again on the grassy campus of the agricultural 

 college at Corvallis long lines of pocket-gopher hills added more 

 biological interest than beauty to the closely mown turf. The 



FIGURE 56. Range of five forms of pocket gophers in 

 Oregon: l,Thomomys bulbivorus; 2, T. bottae leu- 

 codon; 3, T. &. laticeps ; 4, T. townsendii town- 

 sendti; 5, T. t. nevadensis. Type localities circled. 



