FOOD HABITS OF SHOAL-WATER DUCKS. 9 
beetles (Coleoptera), 0.04; dragonflies and damselflies and their 
nymphs (Odonata), 0.01; and other insects, 0.03 per cent. 
One Oregon bird had made almost a full meal of adult caddisflies 
in October, and the tube-shaped larval cases were found in the 
stomachs of 8 others. 
The Diptera usually consisted of larvae or pupae, but occasion- 
ally of adult flies. Six families were represented, as follows: Crane- 
flies (Tipulidae), found in 1 stomach; midges (Chironomidae), in 
10; soldierflies (Stratiomyidae), in 2; horseflies (Tabanidae), in 1; 
Borboridae, in 3; and Ephydridae, in 8. ! 
The bugs taken were chiefly aquatic. Water boatmen (Corixidae) 
had been eaten by 25 gadwalls, creeping water bugs (Naucoridae) 
by 6, and water striders (Gerridae) by 4, while shorebugs (Saldidae), 
stink bugs (Pentatomidae), and plant hoppers (Fulgoridae) were 
taken by 1 each. 
The most common Coleoptera were water scavenger beetles 
(Hydrophilidae), predacious diving beetles (Dytiscidae), ground 
beetles (Carabidae), leaf beetles (Chrysomelidae), and weevils 
(Rhynchophora). Other families represented were rove _ beetles 
(Staphylinidae), larder beetles (Dermestidae), ladybugs (Coccinel- 
lidae), pill beetles (Byrrhidae), leaf chafers (Scarabaeidae), darkling 
beetles (Tenebrionidae), flower beetles (Anthicidae), and blister beetles 
(Meloidae). Of the 362 birds taken during the fall and winter months, 
only 23 had eaten beetles, and these never amounted to more than 4 
per cent of the stomach contents. Of 11 ducklings taken in July, 
however, all but one had eaten beetles; in three instances these 
amounted to 15 per cent, and constituted 7.09 per cent of the food 
of all. 
Two gadwalls had eaten nymphs of dragonflies (Anisoptera), two 
those of damselflies (Zygoptera), and one an odonate nymph, too 
badly ground to be identified. 
The miscellaneous insects consisted of a few ants, ichneumons, 
etc. (Hymenoptera), and a caterpillar (Lepidoptera). Together they 
amounted to only 0.03 per cent. 
CRUSTACEANS (CRUSTACEA), 0.08 PER CENT. 
Crustaceans evidently are not much sought after by the gadwall. 
Twenty-one birds had eaten very small bivalved crustaceans (Ostra- 
coda), usually in small numbers. Three gizzards contained the 
fingers of crabs, two the remains of crawfish, and one a sowbug 
(Oniscus asellus). Altogether. crustaceans furnished only 0.08 per 
cent of the gadwall’s food. 
MISCELLANEOUS ANIMAL FOOD, 0.08 PER CENT. 
The stomach of a gadwall from an open lake in northeastern 
Arkansas contained several hundred of the small reproductive buds, 
