FOOD HABITS OF SHOAL- WATER DUCKS. 27 



Beetles (Coleoptera) amounted to 2.62 per cent of the food of the 

 blue-winged teal, or less than one-tenth of the total animal matter 

 eaten. Ten species of predacious diving beetles (Dytiscidae) were 

 noted, 7 of ground beetles (Carabidae), 5 of water scavenger beetles 

 (Hydrophilidae), 4 of crawling water beetles (Haliplidae), 3 of leaf 

 chafers (Scarabaeidae), 3 of leaf beetles (Chrysomelidae) , 2 each of 

 snout beetles (Curculionidae) and billbugs (Calandrinae), and 1 each 

 of whirligig beetles (Gyrinidae), shining carrion beetles (Histeridae) , 

 pill beetles (Byrrhidae), and mud beetles (Heteroceridae) ; while 

 many individuals of most of these families were found which, on 

 account of their fragmentary condition, could not be further identi- 

 fied. Unclassified beetle remains were found in 50 stomachs. 



The nymphs or young of damselflies (Zygoptera) and dragonflies 

 (Anisoptera) live in the water and afford delicate morsels for ducks. 

 Twenty-two of the blue-winged teals had eaten nymphs of dragon- 

 flies and two those of damselflies, while three stomachs contained 

 remains of nymphs which were not identified. 



Bugs (Heteroptera and Homoptera) constituted 0.86 per cent of 

 the birds' diet. These represented 10 families, besides the remains 

 of a few bugs which were not identified. Water boatmen (Corixidae) 

 had been eaten by 43 birds, creeping water bugs (Naucoridae) by 

 15, back swimmers (Notonectidae) by 12, water striders (Gerridae) 

 and broad-shouldered water striders (Veliidae) by 2 each, and negro 

 bugs (Corimelaenidae) , stink bugs (Pentatomidae), giant water bugs 

 (Belostomatidae) , planthoppers (Fulgoridae), and leafhoppers (Jas- 

 sidae) by 1 each. 



Only 0.65 per cent of the blue-winged teal's food consisted of two- 

 winged flies and their larvae and pupae. Six families were repre- 

 sented, and unidentified larvae or pupae were taken from 8 stomachs. 

 The larvae of soldierflies (Stratiomyidae) and midges (Chironomidae) 

 were present in 11 gizzards each, while those of flower flies (Syr- 

 phidae) had been eaten by 4 birds, and Anthomyiidae, Ephydridae, 

 and black flies (Simuliidae) by 1 each. 



The miscellaneous insect food consisted of unidentified fragments 

 of insects, a grasshopper or two, 3 small moth cocoons, a few ants, 

 insect eggs, etc. 



CRUSTACEANS (CRUSTACEA), 1.93 PER CENT. 



Crustaceans furnished 1.93 per cent of the contents of all the 

 blue-winged teal gizzards examined, and consisted of beach 

 fleas, scuds, etc. (Amphipoda), found in 7 stomachs; small bivalved 

 crustaceans (Ostracoda), in 8; and stalk-eyed crustaceans (Decapoda), 

 in 2. The last-mentioned order includes the claw of a crab found in 

 one stomach and a sand shrimp (Crangonyx gracilis) in the other. 

 Two North Carolina stomachs collected in March were nearly filled 



