DALLES POCKET GOPHER 5 



Plot 1, meadow A. — Grazed area free of pocket gophers from fall 1931 

 until 1940. Gophers reintroduced in 1940 at the rate of 16 per acre and 

 kept there for the remainder of the study. The number reintroduced 

 was sufficient to form a gopher population which was average for 

 Oregon meadows. 



Plot 2, meadow A. — Ungrazed area freed of pocket gophers from fall 

 1931 until 1940. Gophers reintroduced during 1940 as in plot 1 and 

 kept for the remainder of the study. 



Plot 3, meadow B. — Grazed area with pocket gophers from 1931 until 

 1940 and then freed of the gophers for the remainder of the study. 



Plot 4, meadow B. — Ungrazed area with pocket gophers from 1931 

 until 1940 and then freed of the gophers for the remainder of the study. 



From 1932 through 1940 photographs were taken every 2 years of 

 eight quadrats permanently staked at random on each of the four plots, 

 and the plant species there were recorded. This record furnished quali- 

 tative information on vegetation composition or change. 



Beginning in 1940, and for the remainder of the study, 5 estimates of 

 vegetation density were made on the 4 plots by averaging density on 16 

 permanently staked 100 square-foot circular samples. Density was deter- 

 mined for each species by the square-foot-density method (8). This made 

 possible quantitative comparison of vegetative changes on the plots 

 from 1940 to 1948, inclusive. Photographing the 8 quadrats on each plot 

 was continued until the close of the study. 



Throughout the study, meadows A and B were kept practically free of 

 all rodents, other than pocket gophers, by poisoning. The rodents, prin- 

 cipally Oregon ground squirrel and meadow mouse, were kept at a 

 minimum so as to restrict the effect of the mammal population on the 

 meadows to pocket gophers, sheep, and deer. 



THE DALLES POCKET GOPHER 



The Dalles pocket gopher 6 is a robust animal, with a short neck and 

 short legs (fig. 3). Average body length of the adult male is 5.6 inches; 

 its sparsely haired tail is 2.6 inches long; and its hind feet, 1.08 inches 

 long. The average October weight of 33 adult males was 107.8 grams; 

 the largest one weighed 138.8 grams. Thirty-eight females had an aver- 

 age weight of 84.8 grams, the largest weighing 113.3 grams. Young 

 gophers develop rapidly — the average weight of 26 October specimens 

 between 5 to 6 months old was 70.8 grams, with the greatest weight 92.7 

 grams. 



The coloring of the soft hair of the Dalles pocket gopher is alike in 

 both sexes. In the summer the upper parts of the animal are light russet, 

 the nose and the area around the ears are blackish, and the tail is brown 

 with a nearly white tip; its belly is buff and more lightly furred than 

 the upper parts. The skin is so loose that it gives the impression that the 

 animal can turn within it or that it is suitable for a larger animal. 

 Young gophers 7 are of a lighter shade than the adults, and their pelage 



5 Estimates were made on all plots when the Kentucky bluegrass was in the boot — 

 in 1940. 1943, 1945, 1946. 1947, and 1948. 



6 For a discussion of the habits and economic status of pocket gophers generally, see 

 (/) and (6) . 



7 Newborn gophers are helpless, hairless, and gray. They emit tiny squeaks, the only 

 vocal sound the gopher ever makes. 



