1936] MAMMALS OF OREGON 103 



utter a shrill squeal or scream in very distressed tones. One night 

 near the writer's cabin pitiful screams were heard repeated in fainter 

 and fainter tones until they died out in the darkness. In the morn- 

 ing one of these rabbits 1 was found just back of the cabin. It had 

 been killed and partially eaten by some small carnivore, apparently 

 a skunk, possibly the little spotted skunk that lived under the cabin. 

 It was probably a sick rabbit. 



Usually jack rabbits are ease-loving animals, hopping quietly about 

 in search of dainty grasses, nibbling and chewing contentedly in the 

 meadows, but always on guard with long ears tilted and turned to 

 catch the faintest sound of possible enemies. Their keen eyes are 

 also constantly on duty; and, unless well hidden where there is a 

 chance of escaping observation, they are quick to take alarm and 

 speed away at the first sign of danger. A healthy rabbit in good 

 running condition will easily outdistance any of its native enemies, 

 wolves, foxes, coyotes, and all but the swiftest-running hunting dogs. 

 In eastern Oregon their speed has frequently been tested by automo- 

 bile speedometer and found to be about 35 miles per hour at a 

 maximum. They are frequently run over in the roads and killed by 

 cars speeding beyond this. When sick or diseased, however, their 

 speed is greatly reduced and they are easily picked up by almost 

 any of their enemies, even becoming so stupid and slow as to become 

 a prey to skunks and badgers. 



Breeding habits. The increase of rabbits is at times very rapid. 

 Again in dry seasons or in times of scarce food it seems to be rela- 

 tively slow. The normal number of young in a litter is apparently 

 4 to 6, but sometimes may be as many as 8. The mammae are ar- 

 ranged in 6 pairs, 2 each of inguinal, abdominal, and pectoral, on 2 

 long parallel mammary glands. The females give a copious supply 

 of milk, and the young are nursed until nearly half grown before 

 being turned adrift to shift for themselves. Little is definitely known 

 of the dates of birth and the number of litters raised in a year, as 

 both apparently vary with the character of the season and the food 

 supply. In June, young are found varying from just out of the nest 

 and hopping about, to half grown, but as late as the middle of July 

 young that are not half grown are often seen, indicating an irregular 

 breeding season or that more than one litter is raised during the 

 season. The young are well developed and well furred at birth, but 

 there is very little actual knowledge of their early life history. 



Food habits. While the Oregon jack rabbits are mainly desert 

 animals that depend largely upon growing vegetation, at least during 

 the summer period, apparently green grass forms the greater part 

 of their food, and the youngest, tenderest grass is selected, and most 

 of it is nibbled off before it is large enough for even sheep to graze. 

 On favorite feeding grounds the best grasses are often cut down 

 close to the surface of the ground. In very dry times when the 

 young grass is not growing, the best of the other green grass blades 

 are taken, even the saltgrass and tougher varieties. Tules and a 

 great variety of other green plants along the marsh borders are also 

 eaten. At Malheur Lake they were feeding on pigweeds (three or more 

 species), greasewood, leaves and young twigs, shadscales (Atriplew 

 and Grayia), rabbitbrush (T etradymia and Chrysothamnus), and 

 even some of the tips of sagebrush (Artemisia} , but the stomach con- 



