TO 



WILD ANIMALS OF GLACIER NATIONAL PARK. 



their protection. They do not nuike runways, and their presence is 

 rarely detected unless they are occasionally seen when disturbed in 

 the daytime bounding away from one's feet in long leaps through 

 the grass. Their summer nests are usually placed on the surface of 

 the ground and are well concealed by sheltering vegetation. These 

 are neat little balls of grass with a hole in one and sometimes in two 

 sides to serve as doorways. As one steps near a nest the mouse 

 usually bounds out and gives two or three long leaps and then stops to 

 wait for further developments. By noting the place where it stops 

 and by creeping up cautiously one can almost invariably catch the 

 mouse by clapping the hand down quickly over it. When thus cap- 

 tured it does not seem much alarmed, and when held gently in the 

 hands for a little time becomes quiet and may be examined at leisure. 

 The mice rarely offer to bite and seem much more gentle in disposi- 

 tion than most species. If suspended by the tip of the tail one will 



almost invariably curl up 

 until it can reach the base 

 of the tail with its hands 

 and then, like a sailor 

 climbing a rope, come 

 hand over hand up the tail 

 to the fingers holding it. 

 If shaken down it will 

 repeat the operation again 

 and again, much to the 

 amusement of the onlook- 

 ers and with no harm to 

 the ropelike tail. 



The food of jumping 

 mice consists mainly of 

 seeds of grasses and other small plants. To obtain the seed-laden 

 heads of tall grasses they reach up and cut off the stem and draw it 

 down to the ground ; then, repeating tiie operation, they cut off sec- 

 tions and draw the stem down until the seeds are brought within 

 reach. These are eaten and other stems are cut and drawn down in 

 the same manner until a good square meal is obtained. The sections 

 of grass stems thus cut are usually three or four inches long and can 

 always be recognized as the work of this mouse, in distinction from 

 those of the other mice with shorter legs that can not reach so high 

 and consequently cut their grass stems into shorter sections. Little 

 heaps of these long gi'ass sections scattered through the meadows will 

 often indicate the presence and abundance of the species and give the 

 naturalist a clue to places where his traps will yield specimens. 



The four to eight young are born in the grass nests, and by early 

 autumn have become almost full grown and are laying in a supply of 



Photo, by C. Birdseye. Bf296l 



Fig. 11. — Jumping mouse, from photosraph of a 

 captive individual at Florence, ]Mont. 



