R O D E N T J A 297 



FAMILY LEPORIDAE HARES AND RABBITS 



This is a very important family, useful because of the flesh and fur, 

 often harmful to crops because of numbers and food habits. The de- 

 structiveness of rabbits is partly discussed in connection with that of 

 various rodents, in the introductory remarks under Rodentia. Being 

 much larger than most rodents, they individually require more food. 

 Their birth rate is high, so that under favorable circumstances they 

 multiply very rapidly. The common European rabbit is said to breed 

 at the age of six months and to live 7 or 8 years, producing from 4 to 

 8 litters per annum, of from 3 to 8 young to the litter. 1 



As a general rule their natural enemies, such as eagles, hawks, owls, 

 wolves, coyotes, foxes, wildcats and human hunters, keep the rabbits 

 within reasonable bounds, 2 especially the cottontails. Under one great 

 horned owl's nest 100 skulls of cottontails were found. 3 It was long 

 ago declared that in Montana jack rabbits were common only where 

 coyotes and wolves were scarce, 4 but it has been noted also that preda- 

 cious animals sometimes congregate where rabbits are abundant for 

 food. Rabbits are subject to somewhat periodic fluctuations, regardless 

 of predacious animals. The periods in case of the varying hare (snow- 

 shoe rabbit) is about 10 or 12 years, according to Innis, 5 or 7 years, 

 according to Henderson. 6 Such fluctuations, at least in case of jack 

 rabbits, do "not affect the whole country simultaneously, for at the 

 same season the rabbits may fairly swarm in one valley and be scarce 

 in another." 7 This is also true of cottontails in southwestern Colorado, 

 and probably elsewhere. 



Rabbits have many diseases and parasites, 8 and it has been noticed 

 by many observers that when rabbits become very abundant epidemic 

 diseases finally check their further increase and eventually reduce 



Rainier National Park, p. in, 1927. Seton, Lives of game animals, iv, Part 2, pp. 

 636-646, 1929. 



1 Palmer, The jack rabbits of the United States, U. S. Div. Orn. and Mam. Bull. 

 No. 8, 1896; U. S. Biol. Surv. Bull. No. 8, 1897. 



! Bailey, N. Amer. Fauna, No. 49, pp. 134-138, 1926. 



* Bailey, N. Amer. Fauna, No. 25, 157-159, 1905. 



4 Grinnell (G. B.), Rept. of Chief of Engineers, U. S. Dept. War, for 1876, Part 

 3, P. 639. 



5 Innis, The fur trade of Canada, p. 90, 1927. 



6 A. D. Henderson, Cycles of abundance and scarcity in certain mammals and 

 birds, Journ. Mammalogy, iv, 264-265, 1923. 



7 Bailey, N. Amer. Fauna, No. 25, pp. 152-155, 1905. 



8 Schwartz and Snook, Rabbit parasites and diseases, Farmers' Bull., No. 1568, 

 1928. Stiles, A revision of the adult tapeworms of hares and rabbits, Proc. U. S. 

 Nail. Museum, xix, 145-235, 1897. De Ong, Parasites which affect the food value of 

 rabbits, California Fish and Game, I, 142-143, 1914. Dearborn, Rabbit raising, 

 Farmers' Bull., No. 1090, pp. 32-34, 1920. 



