234 College of Forestry 
species in a few hours. Without probably an exception they 
were found near the shores, where there were great numbers 
of the water-breathing univalves. After a number had 
been kept for a few days in a tub there were found in it 
large numbers of the opercles of such mollusks; and in the 
intestines of one were the remains of a crayfish, some fish 
scales and what appeared to be the cases of some kind of 
eaddis-worm. Its broad masticatory surfaces are well fitted 
for crushing the shells of mollusks.” The snails were possi- 
bly Campeloma or Vivipara. 
7. Prepatrory Birp Enemies or MULLUSKS. 
As would naturally be expected, birds enter into competi- 
tion with fish for the acquisition of food. This competition 
is mainly confined to those birds that frequent the water and 
are classed as water birds. To such belong the Black Duck, 
Baldpate, Green-winged Teal, Shoveler, Lesser Seaup Duck 
among the ducks and plover, snipe, ete., among the shore 
birds. Specific references to mollusks used as food of water 
birds are very rare, the usual statement being “ eats snails.” 
A few specific illustrations are given below. 
The Biological Survey, United States Department of 
Agriculture, has conducted food studies for many years. 
Mr. W. L. MeAtee informs me that upwards of 5,000 
stomach examinations have been made of ducks, showing a 
considerable percentage of mollusks. This information will 
eventually be published. 
Marilla affinis (Eyt.). Lesser Scaup Duck. 
A specimen of this bird had eaten the claw of a blue crab 
and 75 snails, mostly Gillia altilis with a few Goniobasis vir- 
ginica and Planorbis albus (Judd, 1902, p. 81). 
Anser albifrons Gambell. White-fronted Goose. 
Audubon (Forbush, 1912, p. 176) states that in Kentucky 
this goose feeds on beech nuts, acorns, young blades of grass 
and snails. 
