22 BULLETIN 862, U. S. DEPARTMENT OF AGRICULTURE. 



shells or bits of shell probably are often taken by ducks in lieu of 

 gravel to help grind the food, but there is no doubt that the mollusks 

 themselves, and especially snails, are relished by the birds and form 

 an important element in their food. Three genera of snails were 

 identified: Physa, Neritina, and Planorbis. Unidentified snails were 

 taken from 44 stomachs, and bivalves from only 3. Broken mollusk 

 shells, unclassified, were found in 90 gizzards. 



CRUSTACEANS (CRUSTACEA), 0.92 PER CENT. 



Small crustaceans, which are abundant in numbers and variety 

 in nearly all streams and bodies of water, whether salt or fresh, are 

 sought by nearly all ducks. They furnished 0.92 per cent of the total 

 food of the green-winged teal, or approximately one-tenth of the 

 animal food. Chief among these were the ostracods, small bivalved 

 crustaceans which might easily be mistaken for minute mollusks. 

 Small shrimplike crustaceans known as amphipods were taken in 

 some numbers, and in one stomach the claws of an unidentified crab 

 were found. 



MISCELLANEOUS ANIMAL FOOD, 0.25 PER CENT. 



A few spiders and mites (class Arachnida), centipeds (Myriapoda), 

 fish scales, minute aquatic animalculae, and other insignificant items 

 form the remainder of the green-winged teal's animal food. 



BLUE-WINGFD TEAL. 



(Querquedula discors.) 

 Plate IV. 



The blue-winged teal, blue-wing, or summer teal is slightly more 

 restricted in its distribution than the green-wing. Although it has 

 been recorded as breeding in Rhode Island, Maine, New Brunswick, 

 Nova Scotia, Newfoundland, Quebec, Ontario, and New York, and 

 as far south as northern Ohio, southern Indiana, southern Colorado, 

 New Mexico, Texas, Utah, northern Nevada, and central Oregon, 

 it is not common east of the Allegheny Mountains nor on the Pacific 

 slope. Its principal summer home is in the interior of North America 

 between the Rocky Mountains and the Great Lakes, from northern 

 Illinois and Nebraska north to Saskatchewan. Its principal range 

 extends north to British Columbia, and it occurs also rarely north to 

 Alaska, Alberta, and about Great Slave Lake. In winter, blue-winged 

 teals are found throughout northern South America south to Brazil, 

 Ecuador, Peru, and Chile; they occur abundantly in Central America, 

 Mexico, and the West Indies ; and in the United States they are found 

 near the Gulf, and as far north as North Carolina, and (sparingly) 

 southern Indiana and southern Illinois. Unlike the green-winged teal, 

 this is one of the least hardy of our ducks, migrating late in spring 



