102 NORTH AMERICAN FAUNA 



[No. 55 



In August 1920, on the south side of Malheur Lake, the rabbits 

 were especially abundant along the edges of the lake marshes, where 

 they gathered in from the sagebrush plains, which at that season were 

 exceedingly dry and where little green food was available. Along 

 the edges of this valley they could be seen at all times of the day. 

 Standing at one point in the open just before sundown the writer 

 counted 69 rabbits. In an old barnyard of about an acre where the 

 saltgrass was especially green he counted at one time (about 5 p. m.) 

 39 rabbits feeding on the grass. Hundreds and thousands could be 

 counted as one walked through the sagebrush or traveled along the 

 roads. These numbers, however, do not apply to the whole of their 

 range, but usually to local areas where they have gathered in from 

 less favorable country. In the immediate Malheur Valley at that 

 time 5 jack rabbits to the acre were estimated, but for their general 

 range not more than 1 to the acre. As they range over nearly half 

 of the State, the total number of these jack rabbits may reach 

 20,000,000 or more. 



General habits. Jack rabbits are largely nocturnal, but their eyes 

 adapt themselves to light or darkness, so that they see well both at 

 night and in the daytime. Unless disturbed, they normally sleep 

 during the middle of the day and probably during the middle of the 

 night also. They are especially active throughout the evening from 

 a little before sundown until it is too dark for human eyes to follow 

 them. They also are active early in the morning, especially just 

 before sunrise ; but if the nights are cold, they usually sit and warm 

 themselves in the early sunlight before hopping quietly away to their 

 forms under the bushes. 



They are a homeless lot, moving where there is food and sleeping 

 where they happen to be at bedtime. Sometimes they merely creep 

 into the shade of a bush and sit there throughout the day unless 

 disturbed, again they dig out a neat form in the shade of a bush or 

 weed, fitting it to their body and smoothing it underneath until some- 

 times the body is half sunk into the ground. The forms vary from 

 an inch to 2 or 3 inches in depth, and some of them seem to have 

 been used for a considerable time. Others are merely temporarily 

 dug out and apparently never returned to. They serve various pur- 

 poses. In hot weather they give better contact of the body with the 

 cool earth, and in cold weather provide partial shelter from cold 

 winds. At all times they aid in concealing the rabbit from its 

 numerous enemies. 



The rabbits make well-worn and conspicuous trails and runways 

 through the brush or weeds, through meadows, fields, and even over 

 the dusty or sandy surface of the desert valleys. In many places 

 seen from the roads and railway trains, these rabbit trails are a 

 conspicuous feature of the landscape and indicate to some extent 

 the abundance of the animals. While the rabbits are peculiarly soli- 

 tary in habits, they are often so numerous as to appear social animals. 

 Usually, however, they seem to pay no attention to each other, even 

 where so numerous as to be feeding or sitting close together. Still 

 they appear to be on friendly terms, and it is rare to see any ani- 

 mosity or even playfulness among them. Apparently they have no 

 calls or voices for communication with each other, and rarely make 

 any sound except when captured or wounded, when they sometimes 



