MALLARD 
27 
acorns, 2.34%; while numerous minor items make up the remainder. The animal 
food is extremely varied and falls into five main groups, of which mollusks consti- 
tute 5.73%, insects, 2.67%, fishes, 0.47%, crustaceans, 0.35% and miscellaneous, 
0.25% of the whole diet. Among the unusual animal foods were remains of frogs 
(found in 19 stomachs), nematode worms, fresh-w'ater bryozoans, marine wmrms, 
earthworms, w'ater mites and spiders. 
I must confess here that the food consumed during the early summer months has 
been much less carefully investigated for all ducks. We do know, however, that 
animal food is a far larger item at that time, and that in young birds for the first six 
weeks it is almost exclusively of this nature. 
By far the most exhaustive account of the food of the Mallard in western Europe 
is to be found in Naumann (1896-1905). According to him the favorite vegetable 
food is the seed of floating manna-grass {Glyceria fluitans) , while among grains they 
show a partiality for barley and oats. The young are particularly fond of duckweed, 
and the various animals found on it. I have already mentioned the fact that in severe 
weather the Mallard in Europe becomes marine in its habits. At such times the food 
may be very similar to the winter food of our Black Duck. Even in July and August 
Mallards have been forced by persecution to resort to salt flats. W. Thompson 
(1851) cites a stomach of one in Ireland which contained an eel four inches in length, 
a crab an inch broad, 948 univalve and bivalve shell-fish of nine species, and 4500 
seeds of eel-grass {Zostera marina). Thirty-three sticklebacks have been found in a 
single crop (London Field, April, 1892). In this connection McAtee cites one stomach 
from Louisiana that contained 28,160 seeds of a bulrush, 8700 of another sedge, 
35,840 of primrose willow, and about 2560 duckweeds, a total of more than 75,200 
items. Another stomach contained 102,400 seeds of primrose willow, which, if sowed 
each one foot apart, would have sufficed to cover twm and a half acres of ground. 
In Greenland the winter food of Mallards consists of small shell-fish such as 
Margarita helicina, Modiolaria and Tellina besides crustaceans (Winge, 1899). 
Flapper Mallards in England have been found with their stomachs distended wdth 
caddis-worm cases, some with larvae, others without (Corbin, 1888). 
With such an omnivorous bird almost every substance is occasionally eaten. In 
Saxony several have been killed with small particles of gold in the stomach, one of 
which weighed 47 mg. (Rey, 1898). They have even been accused of killing trout in 
streams, and in England one was seen to swallow a trout six to seven inches long 
(Armistead, 1888; Mitford, 1888). Their habits are not always cleanly, Audubon 
speaks of their swallowing offal and garbage, even putrid fish, snakes and small 
quadrupeds. On the lower Columbia River (Washington) they have been found feed- 
ing on decaying salmon in February, which rendered the flesh of the birds unfit for 
food (W. L. Dawson and Bowles, 1909). Sanford (in Sanford, Bishop and Van Dyke, 
19031 and several Government collectors speak of their feeding on the maggots in 
