WOOD BATS 121 



When compared with the common round-tailed, house-building wood 

 rat of the western foothills, the bushy-tail is found to be of the same general 

 form, but it is larger and heavier, with longer fur. (See fig. 15.) The 

 hair on its tail is elongated so that this member has something of the flat, 

 brush-like appearance associated with tree squirrels and chipmunks. The 

 dense body coat of the Bushy-tailed Wood Rat is doubtless an adaptation 

 to life in a boreal region. The general configuration of the head and body 

 of this species, especially if seen in a rock slide where the tail may be 

 concealed, reminds one of a cony. 



Fig. 15. Gray Bushy-tailed Wood Rat. Photographed from animal freshly trapped 

 near Vogelsang Lake, August 31, 1915. 



A feature of this wood rat is the musty odor which is associated with 

 both the animal and its home precincts. This odor is produced by glands 

 at the side of the anus, a condition similar to that obtaining in the skunk. 

 Places which are continuously inhabited by the bushy-tail take on this 

 odor, the presence of which furnishes a clue to naturalists who may be 

 hunting for places to trap the animals. 



The present species like its foothill relative is essentially a night prowler. 

 The rat traps, baited with rolled oats, which we set in rock slides at eleva- 

 tions above 8000 feet trapped conies during the daytime and Bushy-tailed 

 Wood Rats at night. On but one occasion did we see a Bushy-tailed Wood 

 Rat abroad during the daytime. On July 18, 1915, four members of our 

 field party had ascended to the summit of Mount Lyell, and while we were 

 eating lunch there a bushy-tail came forth and gathered lunch scraps which 

 we and previous visitors had dropped. Bits of hardtack scattered on 

 the rocks were eagerly sought and devoured, though the rat retired into 

 a crevice to chew them up. No general source of natural food was to be 

 seen on the peak. 



