FOOD HABITS OF MALLARD DUCKS. ie 
mermaid weed. Items of especial interest, although of less impor- 
tance, are huckleberries, of which more than 800 seeds were found 
in one stomach and 200 in another; seeds of a wake-robin, or trillium, 
of which one bird had devoured 523; of sea purslane, reaching a 
total of 800 in the single instance found; and of common ragweed, 
900 of which had been consumed at a single meal. Seeds said by 
Nuttall to be taken by the black duck additional to the vegetable 
food revealed by these stomach examinations are of a bog plant, 
Scheuchzeria palustris. 
ANIMAL Foon. 
As usual, the animal food consists of a larger number of different 
items than the vegetable, although individually these are of very much 
less importance than the plants. In all, they compose 24.09 per cent 
of the total. A little over half of this, namely, 12.27 per cent, is made 
up of mollusks or shellfish. Both bivalve and univalve shells are 
eaten, but many more of the latter, in accordance with their greater 
abundance. Of the bivalves, the common blue mussel (Mytilus 
edulis) is most important. It was found in 35 stomachs, and to the 
number of 30 in a single instance. This shellfish is enormously 
abundant, and although used to some extent for food and fish bait, 
can not be said to have a value that renders the birds feeding upon 
it economically injurious. ) 
Univalves were taken in all nee, including eggs. No fewer than 
650 snails were found in one stomach and of univalves and bivalves 
together 1,200 were present in a single case. Shells of the genus 
Litorina are frequently taken, and five species were identified. A 
common introduced form, L. rudis, was found in 38 gizzards, in one 
to the number of 150 individuals. 
Crustacea, including barnacles, sand fleas, water fleas, sowbugs, 
shrimps, crawfishes, and crabs, are next in importance to Mollusca 
in the animal food of the black duck. They compose 7.99 per cent 
of the total diet. Hundreds of the smaller kinds were present in 
some stomachs, as were also as many as 60 sowbugs and 30 c¢rabs. 
In asingle instance a specimen of the common edible crab (Callinectes 
sapidus) was identified. 
The other items of the animal food that form noteworthy per- 
centages are insects and fishes. The insects taken are largely aquatic 
beetles and bugs, but dragonflies, especially in their immature stages, 
earwigs, crickets, grasshoppers, caddisflies and their larve, two- 
winged flies, and ants also are taken. The rice water weevil was 
among the beetles eaten, 20 being found in one stomach. In all, 
insects amount to 1.89 per cent of the food. Fishes and their eggs 
were found in 20 stomachs and compose 1.34 per cent of the subsist- 
