FAMILY OF POCKET GOPHERS 



267 



California Pocket Gopher. — Thomomys bottac bot- 

 tae (Eydoux and Gervais). Size medium; chestnut- 

 brown above. Coast of California. 



Golden Pocket Gopher. — Thomomys aureus aureus 

 Allen. Size large : golden-yellow above. Utah, 



Pallid Pocket Gopher. — Thomomys pcrpaHidus 

 (Merriam). Size medium; color very pale. Desert 

 regions of southern California and .\rizona. 



Pygmy Pocket Gopher. — Thomomys clusius clusius 

 Coues. Smallest species known ; colors pale. Wyo- 

 ming, Utah and Idaho. 



Brown Pocket Gopher. — Thomomys fuscus fuscus 

 (Merriam). Size small ; chestnut-brown above. Found 

 in Idaho. 



Nevada Pocket Gopher. — Thomomys nevadcnsis 

 Alerriam. Large ; two color phases, pale buff and 

 plumbeous slate. Nevada. 



Black Pocket Gopher. — Thomomys nigcr Merriam. 

 Size medium ; black. Western Oregon. 



Canada Pocket Gopher. — Thomomys talfoidcs tal- 

 poidrs (Richardson). Size large; grayish black. Sas- 

 katchewan region south to upper Missouri. 



If the farmers and fruit growers of the United 

 States were polled on the qtiestion, " Which of 

 the rodents. Field Mice, Rabbits, or Pocket 

 Gophers, do you consider j'our worst pest?" the 

 probability is that the unenviable distinction 

 would be conferred on the Pocket Gopher. Rab- 

 bits work above-ground and protective measures 

 can be taken against their depredations ; Pocket 

 Gophers operate under-ground, and, conse- 

 quently, their ravages can seldom be forestalled. 



The three genera of this family that occur in 

 the United States are differentiated from one 

 another by the kind of grooves which they have 

 on their upper front teeth. In the largest genus, 

 Thomomys, the upper incisors have each a very 

 fine groove on the margin or none at all ; in the 

 genus Gcomys the species have two distinct 

 grooves ; and in Cratogeomys there is one 

 median furrow only. It is these sharp, power- 

 ful incisors which cause all the trouble for the 

 farmer. Not only are they used in digging bur- 

 rows or tunnels, which often admit surface 

 water, leading to the washing of deep gullies, and 

 sometimes cause breaks in canal banks and 

 levees, but with them these " pesky little var- 

 mints " gnaw the roots of fruit and other trees, 

 causing serious damage. Mr. David E. Lantz 

 (Yearbook of U. S. Dept. of Agriculture, 1909), 

 relates that in Heppner, Oregon, the owner of an 

 orchard was absent from home but a week, and 

 found on his return that Gophers had destroyed 

 forty of his choice fruit trees. Originally these 

 animals fed on the stems and roots of native 

 plants ; but no sooner had the settler introduced 

 cultivated grasses and vegetables than the 

 Gophers turned their attention to clover, alfalfa, 

 and the sticculent products of the gardens. 



How swiftly the Gopher works when gnawing 

 roots may be realized from observations of a 

 tame animal made by Vernon Bailey. He 

 says (" Pocket Gophers of the United States ") : 

 " The upper front tooth, or incisor, is used 



chiefly to anchor the animal to the root to be 

 operated on, while the lower incisor does most 

 of the work, playing rapidly back and forth like 

 a steam dri'.l tintil a piece is cut off and passed 

 into the mouth. The cutting edges of the enamel 

 plates of the molar teeth are the tools that re- 

 duce the food. The plates are arranged in such 

 a way that thirty-eight distinct single cuts are 

 made by the forward stroke of the jaw and 

 twenty-eight by the backward stroke. In a tame 

 Gopher it was ascertained by actual count that 

 200 complete strokes are made each minute. On 

 this basis the number of cuts made each ininute 

 of the forward stroke would be 7600, and on the 

 backward stroke 5600, making a grand total of 

 13,200 cuts a minute while the jaws are in active 

 operation." 



Pocket Gophers are strict vegetarians, subsist- 

 ing mainly on roots, tubers, grass and the suc- 

 culent parts of plants. They are not known to 

 drink, and persons who have kept them in con- 

 finement have never succeeded in inducing 

 them to do so. They derive the necessary water 

 from the plants on which they feed. As their 

 eyes are small and their vision limited, they 

 must depend on touch, taste, and smell in select- 

 ing their food. In each cheek is an external 

 hair-lined pouch in which the animals carry food 

 to their storehouses. These pouches are never 

 used for conveying dirt in burrowing, as has 

 often been inaccurately stated. Enough food 

 for a good meal can be collected and stowed 

 away in these pouches in half a minute. 



Railey says the flesh of the Gopher is " tender 

 and well flavored, and, were the animals large 

 enough, they might be made a valuable adjunct 

 to our meat supply." That many birds and 

 beasts consider them dainty morsels is evidenced 

 by the long list of their natural enemies, includ- 

 ing hawks, owls, foxes, wild cats, and above 

 all the weasel and the bull, or gopher, snake. 



Pocket Gophers are not wholly nocturnal ani- 

 mals ; they do not hibernate ; only one litter a 

 year is raised ; and the number of young is from 



