122 ECONOMIC MAMMALOGY 



Having seen that the Felidae, Canidae, many of the Mustelidae, 

 Rodentia and other mammals indulge more or less in the destruction 

 of birds, we find that, on the other hand, many birds are persistent de- 

 stroyers of mammals. This subject has been very much discussed in 

 the literature of economic ornithology and elsewhere. 22 Eagles and the 

 larger hawks and owls destroy many rabbits, squirrels, prairie-dogs, 

 gophers and other rodents, eagles even attacking coyotes, badgers, 

 antelope, wild sheep, wild goats, deer and domestic stock, while many 

 hawks and owls live largely upon mice and other small injurious ro- 

 dents. Of the hawks and owls, fifteen species in the United States are 

 listed as enemies of ground squirrels, five as enemies of pocket gophers, 

 seventeen as enemies of rabbits and eleven as enemies of brown house 

 rats. 23 



In 571 pellets of the barn owl there were remains of 1131 meadow 

 mice, 240 white-footed mice, 153 harvest mice, 85 pocket gophers and a 

 number of other small mammals. 24 Another lot of pellets contained one 

 shrew, 84 pocket gophers, 4 pocket mice, 26 harvest mice, 52 white- 

 footed mice, 276 meadow mice, 2 house rats, 37 house mice, 2 rabbits, 

 i song sparrow and 3 Jerusalem crickets. 25 



Besides the so-called birds of prey, gulls, ibises, storks, spoonbills, 

 cranes, herons, ravens, crows, magpies, jays, shrikes and many other 

 species of birds destroy multitudes of mice and other small mammals. 

 One species of hawk in Africa is especially adapted to feeding upon 

 bats and is consequently called the bat hawk. 26 



22 See Henderson, The practical value of birds, pp. 76-78, 189-204, etc., 1927, with 

 numerous references to other publications in footnotes. 



23 Grinnell, G. B., Eagles' prey, Journ., Mammalogy, x, 183, 1929. Fisher, The 

 hawks and owls of the United States in relation to agriculture, U. S. Div. Orn. and 

 Mamm. Bull. No. 3, 1893; Yearbook U. S. Dept. Agric. for 1907, pp. 329-342; ibid. 

 for 1894, pp. 219-225. Oberholser, The North American eagles and their economic 

 relations, U. S. Biol. Surv., Bull. No. 27, 1906. Bailey, U. S. Div. Orn. and Mamm- 

 Bull. No. 4. 1893; ibid., No. 5, 1894; Animal life of Carlsbad Cavern, pp. 76-92, 141- 

 147, 1928. Piper, Yearbook U. S. Dept. Agric. for 1908, pp. 301-310; Farmers' Bull, 

 No. 352, 1909. Lantz, Yearbook for 1905, pp. 363-3/6; same for 1909, pp. 209-218; 

 U. S. Biol. Surv., Bull. No. 31, 1907; ibid., No. 33, 1909; Farmers' Bull, No. 896, 

 1917. 



24 Foster, A note on the dietary habits of the barn owl, The Condor, xxix, 246, 

 1927. 



26 Hall, The barn owl in its relation to the rodent population at Berkeley, Cali- 

 fornia, The Condor, xxix, 274, 1927. 



26 Bull. Amer. Mus. Nat. Hist., xxxvii, 551-552, 1917. 



