338 . UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION 



cutting off roots, which is sometimes attributed to the mole. The mole 

 crowds along just beneath the surface in loose soil, leaving ridges in 

 which numerous cracks are visible. The gopher digs tunnels, and the 

 sides of these are left clean cut. During dry weather, especially, the 

 mole often burrows deeply and throws up mounds, but these show no 

 trace of an opening, while those of the gopher do. Many moles have 

 been caught for museum specimens by setting Maeabee gopher traps 

 carefully in the main runs of moles (see p. 345, Special Sets) . 



BREEDING HABITS 



The data recorded with the 2700 specimens of gophers, collected 

 throughout the state, which are now in the University of California 

 Museum of Vertebrate Zoology, form the main basis for the following 

 breeding notes. Gophers have from three to twelve young in a litter. 

 The smallest number of embryos (unborn young) found was three, 

 the greatest twelve, while the average in twenty-eight females from 

 many parts of the state was 5.8. There is evidence to indicate that 

 two litters in a season are frequently raised where food is plentiful, 

 as in alfalfa fields. 



Out of eighteen female gophers taken near San Bernardino, Novem- 

 ber 7 and 8, 1916, four contained small embryos«and all but two of 

 the remainder were ready to breed. The breeding season can perhaps 

 best be gauged by the period of growth of the alfilaria, or "filaree," 

 which, with malva, among our native plants, seems to be the gopher's 

 favorite food. The alfilaria is one of the earliest plants to start after 

 the first fall rains, and the resulting nutritious food supply seems to 

 start the gophers breeding. The nest is underground, and usually 

 placed beneath a stump, rock pile, brush pile, or similar surface 

 protection that will discourage badgers or coyotes from digging. 

 The young remain in it for several weeks after birth, leaving 

 when they are nearly one-third grown and able to forage 

 for themselves. In plowing an abandoned field in San Diego County 

 in the middle of January, 1911, the writer uncovered at the bottom 

 of the furrow near a willow stump a nest containing a mother gopher 

 and four hairless, helpless young, barely able to crawl. 



The following dates show the approximate time of year when the 

 main crop of young begin leaving the nest, though young may also 

 be found foraging for themselves much earlier or later than these dates : 

 southern California, March 20; San Joaquin and Sacramento valleys, 

 April 1 ; Owens Valley, April 15 ; foothills of Sierra Nevada, April 30 ; 

 northwest coast region, May 15. 



