1936] MAMMALS OF OREGON 393 



The old bat with one of her young clinging to her was hung up 

 overnight in a thin cloth sack out of doors where the temperature 

 was decidedly chilly and in the morning both mother and young 

 were fully torpid, cold, and unable to move, but the young still se- 

 curely attached to the nipple and with hooked claws to its mother's 

 fur. Brought into a warm room they soon returned to a fully 

 active state, both warming up and limbering up simultaneously. It 

 seems that temporary hibernation of both old and young is generally 

 possible at any time of year with these as with other bats when the 

 temperature drops below a certain level. 



ORDER MARSUPIALIA: MARSUPIALS 



Family DIDELPHIIDAE: Opossums 



DIDELPHIS VIRGINIANA VIRGINIANA KEBB 

 VIRGINIA OPOSSUM 



Didelphis Virginians Kerr, Animal Kingdom, p. 193, 1792. 



Type locality. Virginia. 



General characters. In size about the same as an ordinary house cat, with 

 pointed nose, naked ears, long, nearly naked and prehensile tail, an abdominal 

 pouch in females where the small and embryonic young are carried and nursed 

 until large enough to come out, or for about 76 days after birth. Fur long and 

 soft, of a light gray appearance; underfur white or creamy in color. 



Measurements. About 780 mm in total length ; tail, 298 ; foot, 70. Weight of 

 adults about 6 to 8 pounds. 



Distribution and habitat. Southeastern United States, from 

 southern New York to Nebraska and Texas. Introduced and well 

 established in California and Oregon. 



Jewett and Dobyns (1929 ', p. 361) have provided an interesting 

 account of the Virginia opossum in Oregon. During the past 6 or 

 7 years, they reported fur trappers along McKay and Birch Creeks 

 and tributaries in Umatilla County had taken opossums in traps set 

 for mink and skunk. There is knowledge of 50 or more being taken 

 in this section. During the trapping season of 1927 and 1928 at 

 least 12 were taken by local trappers. Besides those taken along 

 these streams signs of them have been noted along the Umatilla 

 River above Pendleton, and there are unverified reports of them 

 along the Walla Walla River above Milton. They seem to be well 

 established and thriving in this part of the State. 



One collected on September 9, 1928, in Umatilla County and sent 

 to the Biological Survey for identification proved to be typical 

 Didelphis virginiana virginiana. Investigations brought to light 

 records of at least four opossums brought into Umatilla County and 

 liberated between 1910 and 1921. Sam Walker, an old pioneer on 

 McKay Creek, told of a pair of opossums being liberated by one of 

 his neighbors about 1912, and Walker had one that escaped about 

 the same time. 



L. E. Roy, of Pilot Rock, reported that one sent to him from 

 Oklahoma had escaped about 1921. For such rapid breeders here 

 was ample material for stocking a new region where food and cli- 

 mate are so favorable to the natural requirements of the species. 

 Fortunately the opossums have sufficient value for food, fur, and 

 sport to preclude any danger of their becoming a pest. 



