4IO abstracts: ornithology 



chiefly in its smaller size and decidedly darker mantle. The range of 

 Larus hyperboreus hyperboreus extends over northern Asia, most of 

 Europe, and northeastern North America, while Larus hyperboreus 

 barrovianus occurs in western North America. H. C. O. 



ORNITHOLOGY. — Food habits oj the mallard ducks of the United States. 

 W. L. McAtee. U. S. Dept. Agr. Bull. 720: 1-36. 1918. 



This bulletin contains the results of investigations on the food and 

 food habits of Anas platyrhyncha, Anas rubripes, and Anas fuhigula, 

 three closely allied and important game birds of the United States. 

 Of Anas platyrhyncha, which has furnished most of the breeds of do- 

 mestic ducks, examination of 1725 stomachs, taken at all seasons in 

 22 states of the United States and in 2 Canadian provinces, formed the 

 basis of the author's conclusions. The vegetable elements comprise 

 nine-tenths of the food of this species, and consist principally of sedges, 

 grasses, smartweeds, pondweeds, duckweeds, coontail, wild celery, 

 and various other water plants. Of some, such as Zizania aquatica, 

 chiefly the seeds are eaten, but of many others also the stems, leaves, 

 root-stocks, buds, and tubers are used. Other miscellaneous vegetable 

 items, such as seeds of trees like Planera aquatica and of shrubs like 

 Celtis, together with some acorns, are taken. The animal food of the 

 mallard, which is only about one-tenth of the whole, is made up chiefly 

 of insects and mollusks. 



An interesting fact in connection with the stomach examinations of 

 this species is the large number of individual items which sometimes are 

 present. In a single stomach taken in Louisiana there were found 

 75,200 seeds of various water plants, and in another taken in the same 

 State, 102,400 seeds of Jussiaea leptocarpa. 



Of Anas rubripes, including its subspecies Anas rubripes tristis, 622 

 stomachs were examined, chiefly from the United States. In these the 

 vegetable food made up 76 per cent of the contents, and consisted chiefly 

 of pond-weeds, grasses, sedges, and smartweeds, together with many 

 other less important items. The animal food, which was 24 per cent of 

 the whole, was mostly mollusks, crustaceans, and insects. 



The Florida duck. Anas fulvigula, including its subspecies Anas 

 Julvigula maculosa, lives on vegetable food, mostly grasses, smartweeds, 

 sedges, water lilies, pondweeds, and other water plants, to the extent 

 of 60 per cent of its total food; and on animal diet, mostly mollusks, 

 insects, and crustaceans, to the extent of 40 per cent. 



