38 BULLETIN 862, U. S. DEPARTMENT OF AGRICULTURE. 
the seeds and other parts of submerged plants) by half-diving, 
after the manner of the mallard and several other ducks. 
The stomachs of 413'° wood ducks were available for examination. 
Six stomachs were rejected on account of the too meager or uncertain 
nature of their contents, and seven more from ducks collected during 
January, May, and June, because they were not sufficient in number 
adequately to represent those months. None were taken during 
July; so that the 399 stomachs from which final results were com- 
puted represent only the months from August to December, and 
from February to April, inclusive. There is no reason why the food 
for January should not be similar to that of the other winter months; 
in summer, however, the percentage of animal food no doubt is 
somewhat higher. Stomachs were collected from 24 States and the 
District of Columbia, from Maine and Florida to Oregon and Cali- 
fornia, and from the Province of Ontario to Texas; but about five- 
eighths (268) of the whole number were taken in Louisiana. The 
bulk of the wood ducks, now nowhere abundant as breeders, inhabit 
the Mississippi Valley, and in winter they find ideal feeding and 
living conditions in the cypress swamps and wooded lakes and 
ineoone of the States bordering the Mississippi from about the mouth 
oo the Ohio River southward. 
VEGETABLE Foon. 
‘More than nine-tenths (90.19 per cent) of the food of the wood 
duck consists of vegetable matter. This high proportion of vege- 
table food is very similar to that taken by the mallard. With the 
wood duck it is quite evenly distributed among a large number of 
small items, chief among which are the following: Duckweeds, 10.35 
per cent; cypress cones and galls, 9.25; sedge seeds and tubers, 9.14; 
grasses and grass seeds, 8.17; pondweeds and their seeds, 6.53; 
acorns and beechnuts, 6.28; seeds of waterlilies and leaves of water 
shield, 5.95; seeds of water elm and its allies, 4.75; of smartweeds and 
docks, 4.74; of coontail, 2.86; of arrow-arum and skunk cabbage, 
242 - of bur marigold and other composites, 2.38; of buttonbush 
and allied plants, 2.25; of bur reed, 1.96; wild celery and frogbit, 
1.31; nuts of bitter pecan, 0.91; grape seeds, 0.82; and seeds of swamp 
privet and ash, 0.72 per cent. The remaining 9.4 per cent was made 
up of a large number of minor items. 
‘DUCKWEEDS (LEMNACEAE), 10.35 PER CENT. 
Whenever present in the feeding grounds of the wood duck, duck- 
weeds probably are its favorite food. Each individual plant con- 
sists simply of a small fleshy leaf, disk shaped or nearly so, floating 
on the surface of the water, with one or more simple roots dangling. 
13 Highty-six of these were examined by W. L. McAtee. 
