FOOD HABITS OF SHOAL-WATER DUCKS. 35 
WATER MILFOILS (HALORAGIDACEAE), 0.21 PER CENT. 
Water milfoils are usually submerged plants, bearing hara, nutlike 
seeds in the axils of the finely dissected leaves. The seeds, and 
sometimes bits of the leaves, are picked off occasionally by ducks. 
Seeds of water milfoil (Ayriophyllum sp.) were found in 24 of the 
pintail stomachs, of bottle brush (Hippuris vulgaris) in 12, and 
mermaid weed (Proserpinaca sp.) in 6. 
MISCELLANEOUS VEGETABLE FOOD, 5.99 PER CENT. 
The seeds of many species of plants not already mentioned were 
found in stomachs of pintails, sometimes in comparatively large 
series, but then only in small numbers. In this category are seeds of 
myrtles or bayberries (JM/yrica spp.), found in 45 gizzards; brambles 
(Rubus spp.), in 43; elders (Sambucus spp.), in 32; bur reed (Spar- 
ganium sp.), in 32; wild heliotrope (Heliotropium indicum), in 28; 
hornwort or coontail (Ceratophyllum demersum), in 23; crowfoots 
(Ranunculus spp.), in 17; pigweeds (Amaranthus spp.), in 15; 
hawthorns (Crataegus spp.), in 12; grapes (Vitis spp.), in 11; mallows 
(Malvaceae), in 10; and many others. Bits of spruce needles (Picea 
sp.) had been picked up, probably from the water, by 21 of the 
ducks; four pintails had eaten leaves or rootstocks of wild celery 
(Vallisneria sprralis). The remainder of the miscellaneous vegetable 
food consisted entirely of seeds. 
ANm™AL Foop. 
The animal portion, 12.85 per cent, of the food of the pintail was 
made up of mollusks, 5.81 per cent; crustaceans, 3.79 per cent; 
insects, 2.85 per cent; and miscellaneous, 0.4 per cent. 
MOLLUSKS (MOLLUSCA), 5.81 PER CENT. 
Mollusks were found in 326 of the 790 pintail stomachs examined. 
In 44 they constituted 50 per cent or more of the contents, and in 5 
they reached 100 per cent. Practically all of a large series of stom- 
achs from the Pacific coast of Washington contained mollusk shells. 
Univalves (Gastropoda) predominated over bivalves (Pelecypoda) 
in the food of the pintail, but large numbers of small species and 
young of the latter were taken. In many instances mollusks could 
not be identified because of the great efficiency of the duck stomachs 
as erinding machines. 
CRUSTACEANS (CRUSTACEA), 3.79 PER CENT. 
Remains of crabs were found in 28 of the pintail stomachs, crawfish | 
in 4, and shrimps in 2. Ten ducks shot near the eastern end of 
Long Island, New York, had been feeding very largely upon a small 
