118 



NORTH AMERICAN FAUNA 



[No. 55 



any other park squirrels. In the forest the most stealthy methods 

 and much patience are necessary to get sight of one, and then, when 

 the observer is discovered, the squirrels vanish as if by magic on 

 the opposite sides of trees and branches, where they hide with such 

 skill and persistency that rarely can one be seen again unless two 

 people work together on opposite sides of the tree. 



Their homes are generally in hollow trees where these can be 

 found, but large leaf and stick houses are also built in the forks or 

 branches of trees, well-matted structures sometimes as large as a 

 half-bushel measure with thick walls and a dry, warm nest cavity 

 in the center. These are especially the summer nests, but in some 

 cases evidently are used also through the winter. 



The squirrels are usually silent and shy, but where permanently 

 protected or far back in the forest where rarely hunted, an occa- 

 sional husky bark is 

 heard, not unlike the 

 voice of the eastern gray 

 squirrel if this were more 

 than doubled in volume, 

 but slower and hoarser, a 

 soft chuff, chuff, chuff, 

 seemingly both a call 

 and a warning signal of 

 danger. The writer has 

 heard it only in late sum- 

 mer or autumn when the 

 nearly full-grown young 

 were out feeding in the 

 treetops. 



Breeding habits. The 

 adult females have 4 

 pairs of mammae 1 inguinal, 2 abdominal, and 1 pectoral and the 

 usual number of young in a litter in apparently 4. The main mating 

 season seems to be in January and February, as indicated by a note 

 from C. H. Townsend in Shasta County, Calif., where on January 13, 

 1883, he collected 5 males. The males, he said, gather in groups in 

 January and February, and frequently he shot half a dozen males out 

 of a single tree (1887, p. 174). This is the same as the gray squir- 

 rel custom in the mating time. On March 25, 1855, at Fort Dalles, 

 Suckley records a "female having young was seen" (1860, p. 95). 

 In California a female containing 2 small embryos was taken April 

 27, by Frank Stephens, and another with 2 embryos on June 2, by 

 A. S. Bunnell. Another collected by J. F. Ferry in Humboldt 

 County, Calif., October 30, was nursing young. These early and late 

 dates indicate 2 litters a year while the small number of 2 embryos 

 only mean the first litters of last year's young, which are irregular 

 in their time of breeding. Adult squirrels are usually very regular 

 in their dates of breeding, and with the eastern gray squirrel the 

 question of a second litter seems to depend entirely on the food 

 supply. 



Food habits. The presence of the squirrels can often be told 

 by the remains of their meals, the scales of large pine cones scat- 

 tered over the ground under the feeding trees or the scattered shells 



FIGURE 19. Range of Oregon gray squirrel, Sciurus 

 griseus griseus, in Oregon. Type locality circled. 



