COLD AND WARM WEATHER BIRDS. 13 
of time altogether depending upon the amount of 
water and food supply. In the fall migration the first 
issue can be observed after cold weather has begun, 
with its storms of snow and sleet; should this continue, 
and a freeze-up follow, they pour down from above 
the Canadian line, excepting those hatched in the far 
north, which, however, are working their way toward 
our boundaries. The first and second issues can usu- 
ally be distinguished by their numbers, even if one 
succeeds the other rapidly. They appear loath to 
leave the north, and hang around as long as water 
can be found and no snow be present; for snow will 
drive ducks back more than any other weather. They 
attain their full plumage by the time they reach the 
borders of the United States. The spring flight is 
practically over the same grounds during a wet spring, 
although they now merely pass by many places where 
twenty years ago they swarmed over the country. 
The fall flight is over the various chains of lakes and 
sloughs, down the large water-courses; the wetness of 
the fall determining their abundance or scarcity. 
The feeding grounds are in wheat, barley and corn 
fields, sloughs, shallow lakes and ponds. ‘They are 
very fond of the various berries which grow so pro- 
fusely upon the northern islands and mainland of the 
extreme north, and which greet them upon their 
spring arrival; the bulk of which they could not ob- 
tain in the fall, owing to the snow which covered them, 
but which under its snowy mantle kept sweet and 
fresh for their spring supply. 
The playgrounds are open water in corn or barley 
fields, pond holes, in sloughs, musquaids, ete. Their 
