256 ECONOMIC MAMMALOGY 



ogists often find snail shells which have been broken by squirrels. 

 Squirrels are known often to eat fungi, even some species which are 

 injurious to human beings. 2 



Many species of squirrels are more or less insectivorous, some highly 

 so. Of the contents of 22 stomachs of striped ground squirrels (Citel- 

 Itis tridecemlineatus) from the Mississippi Valley, 46 per cent consisted 

 of insects, "almost exclusively injurious species," averaging 13 cut- 

 worms and webworms each; and in 80 stomachs 52.9 per cent of the 

 contents was animal matter, chiefly insects, and 44.4 per cent vege- 

 table matter. Franklin ground squirrel (C. franklini) : 29 stomachs, 

 animal matter 30.3 per cent, mostly insects; vegetable matter 68.5 

 per cent, mostly seeds and grain. Richardson ground squirrel (C. 

 richardsoni) : 18 stomachs, animal matter 9.5 per cent; vegetable mat- 

 ter 90.3 per cent. 3 Along the foothills of Colorado the striped ground 

 squirrels "feed on grasshoppers and other injurious insects, almost to 

 the exclusion of all other foods," hence should be protected. 4 Red 

 squirrels eat many insects, according to Hatt. Their ecological rela- 

 tions have been discussed by Klugh. 5 Gray squirrels have been found 

 destroying oak apple galls. 6 A flying squirrel in captivity killed a sap- 

 sucker. Four others in captivity "ate prodigious quantities of pinch 

 bugs and other beetles, as much as a pint at a meal." 7 



2 Odell, Squirrels eating Amanita muscaria, Canadian Naturalist, xxxix, 180-181, 

 1925 ; Further observations on squirrels eating Amanita muscaria, ibid., XL, 184, 1926. 

 Hastings and Mottram, Observations upon the edibility of fungi for rodents, Trans. 

 Brit. Mycolog. Soc., v, 364-378, 1929. Murrill, Animal mycophagists, Torreya, n, 25- 

 26, 1902. Langham, Squirrel eating Melanogaster ambiguus, Irish Naturalist, xxv, 

 136, 1916. Ballou, Squirrels as mushroom eaters, Journ. Mammalogy, vin, 57-58, 

 1927. Dice, ibid., n, 25, 1921. Murie, ibid., vm, 39-40, 1927, citing Merriam, Mammals 

 of the Adirondacks, 1884, and Seton, Life histories of northern animals, Vol. i, 

 1909. Goldman, Journ. Mammalogy, ix, 127-129, 1928. 



3 Bailey, The prairie ground squirrels or spermophiles of the Mississippi Valley, 

 U. S. Div. Orn. and Mamm. Bull. No. 4, pp. 39-46, 55, 67, 1893. Gillette, Food habits 

 of the striped prairie squirrel, Bull. Iowa Agric. Exper. Sta., No. 6, pp. 240-244, 

 1889. Aldrich, Food habits of the striped gopher, Bull. South Dakota Agric. Exper. 

 Sta., No. 30, pp. 8-1 1, 1892. Burnett, Office Colorado State Entom. Circular No. 14, 

 1914. For additional data on the economic status of squirrels and chipmunks see 

 Seton, Lives of game animals, iv, Part 2, 1929. Bailey, Notes on some of the 

 spermophiles and pocket gophers of the Mississippi Valley, Ann. Rept. U. S. Dept. 

 Agric. for 1892, pp. 185-192. Canadian Entomologist, xxxix, No. I, p. 16, 1907. 



4 Burnett, Office Colorado State Entom. Circular No. 18, p. 6, 1916. 



6 Hatt, The red squirrel : Its life history and habits, with special reference to 

 the Adirondacks of New York and Harvard Forest, Roosevelt Wild Life Annals, 

 11, No. i, pp. 1-146, 1929. Klugh, Ecology of the red squirrel, Journ. Mammalogy, 

 vnij, 1-32, 1927; reprinted in Ann. Rept. Smithsonian hist, for 1928, pp. 495-524, 

 "with slight changes in the illustrations." 



6 Oak apple galls destroyed by gray squirrels, Bull. Brooklyn Entom. Soc., xix, 

 91-93, 1929. 



7 Stoddard, The flying squirrel as a bird killer, Journ. Mammalogy, i, 95-96, 

 1919. 



