1867. Sylvilagus Gray, Ann. and Mag. Nat. Hist., 20 (ser. 3):221. Type, Lepus sylvaticus Bachman, Lepus nuttalli mallurus Thomas.
Total length, 291-538; tail, 18-73; hind foot, 71-110; ear from notch (dry) 41-74. Grayish to dark brownish above and lighter below; sutures of interparietal bone distinct throughout life; second to fourth cervical vertebrae broader than long with dorsal surface flattened and without carination.
The delectable flesh of members of this genus, the large numbers that occur on a small area, even in thickly settled rural areas, and the wariness that rabbits soon develop when much hunted, give them top ranking among small game mammals. Tens of thousands of cottontails in Kansas and Missouri (Sylvilagus floridanus and some S. audubonii) are captured alive, transported to the eastern United States and released there to bolster the local supply of game. Considering that certain ectoparasites are limited to certain hosts and that some ectoparasites transmit such diseases as Rocky Mountain Spotted Fever whereas other ectoparasites do not, this transplantation of rabbits is dangerous. Also, expenditure of $100.00 on improving the habitat for Sylvilagus in a given area in the eastern United States would produce more cottontails than the expenditure of the same sum for live animals, from the Middlewest, that are to be released (see Langenbach and Beule, 1942:14, 15 and 30).
Different species venture different distances from cover to feed. The Audubon cottontail of west-central California ventures a hundred feet and more from cover but the brush rabbit was never seen (Orr, 1940:182) farther than 42 feet from cover. In the thirties, when a gladiolus farmer from the chaparral belt of Santa Clara County, California, visited the University of California seeking advice on how to prevent damage by "cottontails" to his gladioli plantings, we asked the farmer if brush rabbits or cottontails were responsible and suggested to the farmer, who was unable to distinguish between the two, that an animal be killed and submitted for identification. When this was done, the brush rabbit (Sylvilagus bachmani) was found to be responsible for the damage. Robert T. Orr's recommendation that the chaparral (brush) be cut back 45 feet from the gladioli plantings was reluctantly followed and proved to be effective. A letter from a Santa Clara County agricultural official a couple of years later expressed thanks for the recommendation made by Orr, and estimated that adoption of his recommendations saved farmers of that one county $40,000 annually. This incident illustrates how detailed knowledge of the life history of a given kind of animal and control of its environment, rather than direct "control" of the animal, is sometimes of value to man.
The genus Sylvilagus is restricted to the New World; the two species Sylvilagus brasiliensis and S. floridanus are the only two which occur in South America and they occur also in North America.
Subgenus BRACHYLAGUS Miller—Pigmy Rabbit
1900. Brachylagus Miller, Proc. Biol. Soc. Washington, 13:157, June 13. Type, Lepus idahoensis Merriam. For characters see subgenus Sylvilagus.
Sylvilagus idahoensis (Merriam)
Pigmy Rabbit
1891. Lepus idahoensis Merriam, N. Amer. Fauna, 5:76, July 30, type from head of Pahsimeroi Valley, near Goldburg, Custer County, Idaho (Davis, Recent Mammals of Idaho, p. 363, April 9, 1939).
1930. Sylvilagus idahoensis, Grinnell, Dixon and Linsdale, Univ. California Publ. Zool., 35:553, October 10.