24 GAME, AQUATIC, AND RAPACIOUS BIRDS. 



item is fresh-water minnows ( Oyprinidse) , 23.3 per cent. Sand launces 

 (Ammodytes americanus) make 17.8 per cent of the food. Other fishes 

 eaten are menhaden (Brevoortia tyrannus), 5.1 per cent; yellow perch 

 (Perca Jlavescens) and sticklebacks (Gasterosteus bispinosus), 4.3 per 

 cent each ; and silvery anchovies (StolepJiorus) , chub mackerel (Scomber 

 colias), and silversides (Menidia), 1 per cent each. 



Only 6 per cent of the bird's food is composed of food fishes. To 

 offset this, 3.5 per cent consists of insects, mostly injurious, and 4.3 

 per cent of sticklebacks, of which a distinguished naturalist (Giinther) 

 says: "It is scarcely to be conceived what damage these little fishes 

 do, and how greatly detrimental they are to the increase of all the 

 fishes among which they live, for it is with the utmost industry, 

 sagacity, and greediness that they seek out and destroy all the young 

 fry that come their way." 



Almost 85 per cent of the food consists of fishes of neutral im- 

 portance. 



Least tern (Sterna antillarum). Almost half (43.1 per cent) of the 

 food of 49 least terns consists of silver anchovies (StolepJiorus) . They 

 were captured from New Jersey to Florida and Louisiana in May and 

 June. Menhaden (Brevoortia tyrannus) compose 6.8 per cent; mum- 

 michogs (Fundulus), 6.3 per cent; silversides (Menidia), 1.1 per 

 cent; and unidentified fish, 37.7 per cent. The remaining 5 per cent 

 of the food is made up of Crustacea. No food fishes were identified 

 from stomachs of the least tern. 



Black tern (Hydrochelidon nigra surinamensis) . The food of the 

 black tern (fig. 10) is more varied than that of any other 

 species. Fish, chiefly minnows (Cyprinidse) and mummichogs (Fun- 

 dulus), compose a little more than 19 per cent of the total con- 

 tents of 145 stomachs. Dragon flies make more than 20 per cent; 

 May flies, 13 per cent; grasshoppers, 12 per cent; predaceous diving 

 beetles, almost 6 per cent; scarabseid beetles, almost 5 per cent; leaf 

 beetles, 3J per cent; gnats and other flies, more than 8 per cent; 

 Crustacea, 3J per cent. Other items of food are ground-beetles 

 (Carabidse), click beetles (Elateridse), weevils, stone flies, caddis flies, 

 water striders, moths, and ants. 



The bird preys upon no food fishes, as far as known, but does feed 

 extensively upon such fish enemies as dragon-fly nymphs, dytiscid 

 beetles, and crawfishes. It takes a great variety of insects, including 

 some of economic importance, as the moth of the cotton bollworm 

 and the fall army worm, click beetles (adults of wireworms), weevils, 

 and grasshoppers. 



Summary. The average percentage of food fishes in the regimen 

 of these five species of terns is only 4.8 per cent. This refutes the 

 charge that they live largely on food fishes. Among the other fishes 



497 



