MAMMALS OF THE REGION 75 



ground and roaming at night in search of food,— grass- 

 hoppers, crickets, beetles, moths, scorpions, spiders, and 

 any other mice or small animals that they can catch, 

 kill, and eat. They possess many of the habits of real 

 hunters, including a call note, a shrill little whistle like 

 the miniature howl of a wolf, by which they keep in 

 touch with each other at night. In the arid regions 

 they take to some extent the place of the moles and 

 shrews of the humid regions in the destruction of 

 ground-dwelling insects and small animal life. In this 

 respect they may well be as useful as birds in helping to 

 maintain a wholesome balance of nature and in control- 

 ling the abundance of injurious forms of life. The owl 

 perhaps deserves no credit for swallowing these useful 

 little animals, and yet we can not be sure that in un- 

 checked abundance even they might develop habits 

 injurious rather than beneficial to our interests. 



Grasshopper mice are thickset little fellows with 

 short, fat tails, medium large ears, and the keen ex- 

 pression of hunting animals. They are dark gray or 

 pinkish buff above and pure white below. 



WHITE-THROATED WOOD RAT 



Neotoma albigula (Fig. 26) 



These rock-loving wood rats are abundant in the 

 caves and canyon walls and every rocky place where safe 

 cover can be found. None was found in the depth of 

 the Carlsbad Cavern where it would be necessary for 

 them to climb out every night to get a supply of green 

 food, but they were living in the great western entrance 



