NORTH AMERICAN GREBES. yaa 
_ ictalops) and another fresh-water sculpin belonging to the same 
genus. Other bony fishes that could not be identified were found 
in 36 stomachs. 
In all, fish remains were encountered in 69 of the 174 stomachs. 
_ The catfishes, eel, perches, and part of the sunfishes taken may be 
- considered valuable; the others have little importance. A part of 
the latter, as the sucker and carp, are used by man, but are not con- 
sidered first-class food fishes. The majority of the unidentified 
bony fishes were undoubtedly minnows of no value except as food 
for other animals of larger size. Fishes were eaten only in small 
quantities from May to August, inclusive, when the birds were on 
their nesting grounds, but formed a considerable part of the food at 
other seasons. | 
The crawfishes eaten by these birds amount to 27 per cent of the 
total food. They occurred less commonly in birds taken in Novem- 
ber than at other seasons. Common eastern forms (Cambarus) 
were taken in 44 instances, and western ones (Potamobius) in 6. 
Crawfishes 34 inches long often were found and from their appear- 
ance and position in the stomach had been swallowed tail foremost. 
In the larger individuals the claws had been sheared off near the 
body before the animals were swallowed. The larger eastern craw- 
fishes sometimes do serious damage in cultivated fields, where they 
destroy young plants or in some cases cause trouble by throwing 
out mud “chimneys.” At times they also cause breaks in the dams 
of artificial ponds by boring holes through them. 
Other crustaceans amount to 4.1 per cent of the food for the year. 
They were taken in December, January, and February and consist 
of shrimps (Crago), prawns (Palaemonetes), and fiddler crabs 
(Uca), Unidentified crustaceans were found 9 times and may in 
part be fragments of crawfishes too far digested to be recognized. 
The insect portion of the food made up 46.3 per cent of the whole. 
Heteroptera (bugs), Coleoptera (beetles), and the groups contain- 
ing the dragonflies and damselflies were best represented. Heter- 
optera alone made up 16.2 per cent of the food and were rather 
evenly distributed throughout the year. The true water bugs, pred- 
atory species, were especially well represented, and members of this 
family (the Belostomidae) were found in 32 stomachs, in 25 of which 
there were remains of the large species belonging to the genus Belos- 
toma, Which contains the familiar giant water-bug, or “ electric-light 
ee These are predacious and are highly destructive to young fry 
of fishes as well as to other aquatic life, so that in the evident predi- 
lection of this grebe for them the bird is rendering good service. 
Back-swimmers (Votonecta) were taken 13 times, and water boatmen 
(Corixidae) 26 times. Four common eastern water-creepers (Pelo- 
coris femoratus), a species that feeds on other insects, were encoun- 
tered, and one water scorpion (/anatra), a curious long-bodied form 
that is also predatory. Heteroptera as a whole were noted in 68 of 
the stomachs examined. 
Coleoptera were found about as often as Heteroptera in the food 
of the pied-billed grebe, as they formed 16.1 per cent of the total 
and were found in 93 stomachs. The majority of these were aquatic 
species of fair size, evidently secured by direct chase. The pied- 
billed grebe apparently is more active in pursuit of prey than the 
