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CIRCULAR 884, U. S. DEPARTMENT OF AGRICULTURE 



at a depth usually of 4 to 8 inches, although they may be shallower or 

 deeper. Feeding tunnels are relatively near the ground surface. In 

 sparsely vegetated areas, where extensive digging is required to obtain 

 adequate food, feeding tunnels are more numerous and extensive than 

 where vegetation is plentiful. Such activity tends to give the appearance 

 of a heavier gopher population than actually exists. 



Each burrow system contains one or more nest cavities 4 to 6 inches 

 in diameter. Runways adjoining these cavities are deeper than the feed- 

 ing runways, their depth varying with individual gophers, drainage, and 

 the soil profile. A vertical shaft extends from the feeding runways down- 

 ward, usually I1/2 to 2i/ 2 feet, but sometimes 5 feet or more, to the 

 cavities. Cavities usually have more than one entrance near the vertical 

 shaft. The nest itself is made of finely shredded dead grass and weed 

 stalks in the form of a pad on the cavity floor. Occasionally hollow balls 

 of shredded material are used as nests in the snow. The pocket gopher 

 is an excellent housekeeper and does not leave refuse in the runways. 

 Small pockets or cavities near the nests are used as middens where un- 

 desired food particles and fecal matter are deposited. 



The gopher digs with its front feet and, where the soil is exceptionally 

 hard, with its teeth, occasionally leaving incisor marks on pieces of the 

 softer stones. As it digs its extensions, it pushes the dirt behind it in the 

 tunnel. Later it removes this excavated dirt through a short gentle-slope 

 tunnel that opens on the surface of the ground. In the process, it uses its 

 head and shoulders in bulldozerlike manner, pushing the loose dirt 

 ahead of it. Sometimes it uses its front feet to put the dirt on the 



F-375596 



Figure 5. — Dalles pocket gopher at entrance to burrow, around which a medium-sized 



soil mound has been built. 



