406 FEATHERED GAME 
than are the bodies of most ducks. This model 
must be necessary, for none of the family need 
such speed in the water as these which feed 
upon an active prey which must often be pur- 
sued some distance before it is captured. It 
is a form easily driven through the air, too, if 
we may argue anything from the forelaying 
necessary to stop a crossing bird in shooting. 
Shelldrakes are generally found in flocks 
ranging from half-a-dozen to twenty, rarely 
more except in migration. Commonly, unless 
there is no danger, they place a watcher over 
the flock while feeding. Usually all but the 
bird on ‘‘sentry go’’ dive together while fish- 
ing so as to leave less opportunity for their 
prey to escape. Often they drive a school of 
small fry into shoal water and pursuing them 
into a narrow place may even force their vic- 
tims high and dry ashore by their furious 
rushes. In such a case they will almost finish 
a school, for they are very voracious feeders. 
The Goosander is the largest of the Amer- 
ican Shelldrakes and somewhat rare in the sea 
except in the winter months when the few that 
do not go south are compelled to dwell upon 
the salt water or in the cabinet of some collec- 
