110 RODENTS OF IOWA 



result sandy regions are not much troubled with this pest, and 

 the sandy sections of the state which have been visited report 

 few of the animals and little damag'e done. While the pocket 

 gopher is not strictly nocturnal in its habits, it is most active in 

 early morning and evening; however, if temperature and weather 

 conditions are favorable it may work all day and on into the night. 

 Hot, dry weather affords little incentive for digging. In worlving 

 its way through the earth the animal uses the powerful upper in- 

 cisors in loosening the soil, while the front feet are also used in 

 digging and in pushing the earth backward beneath the body 

 where it is carried still further backward by the action of the 

 hind feet. After a quantity of earth has accumulated behind the 

 burrower he turns around in the tunnel, places the palms of the 

 front feet vertically beneath the chin and pushes himself and the 

 earth along with his hind feet. On arriving at the opening of the 

 tunnel he forces the earth out to form the so-called gopher "hill." 



The writer has seen such mounds of earth six to eight feet in 

 diameter and a foot or more in height. It is said that on wild 

 prairie land the pocket gopher frequently throws up momids 

 larger than this. The great number of fresh mounds that may 

 appear in a restricted locality during the course of twenty -four 

 hours, indicates that considerable distances are traversed. 



The burrows are usually about two feet beneath the surface and 

 often are quite complicated, forming a kind of network of sub- 

 terranean roads. At intervals of a few feet shafts are run to the 

 surface for the conveyance of the earth that has been removed in 

 the construction of the tunnel. It has been estimated that the 

 burrows of a single animal from one season's burrowing, if straight- 

 ened out, would measure a mile in length. In one of the larger 

 mounds the gopher has its nest where it hoards a supply of food 

 and rears its young. "Apparently pocket gophers breed but once 

 a year, usually early in the spring and they produce from two- to 

 six young in a litter. T. H. Scheffer, of the Kansas State Agri- 

 cultural College, trapped thirty-four pregnant females from Janu- 

 ary 31 to May 13. The smallest number of embryos found was 1 ; 

 the largest 6 ; the average 4.2. While gophers are less prolific 

 than many other rodents, the seclusion in which they live compen- 

 sates in great measure for their lack of fecundity, since their ene- 

 mies have relatively few opportunities to secure them. Except in 



