FALL MIGRATORY FLIGHT OF DUCKS, ETC. 105 
leaves, hardly a duck remains; a cold wind whips in 
from the north, the forerunner of a northern winter. 
Down will come the third issue, pell-mell, in the ad- 
vance of a snowstorm. A flurry of the elements for a 
day or so, a few birds stay around the open water, but 
the moment it freezes up—which is quickly in the 
north—-they depart never to return, even if a thaw 
should afterward occur. 
Their migration (especially among the non-divers) 
is plainly marked, the ducks having first collected 
from all parts into large pieces of open water. The 
divers migrate by themselves. They follow the large 
rivers, chains of lakes and sloughs in the interior; 
along the shores of seacoasts; drifting more inland, 
where marshy land abounds, preferring the night for 
their travels, so that lakes, rivers and large bodies 
oi water which had had few ducks visible upon them, 
find the birds well represented in the early morning. 
The relentless cold of the North, with its sleet, hail 
and snow, steadily pursues them and presses them 
onward, the ducks tarrying here and there as weather 
permits, until they are forced to seek the welcome 
vicinity of the frost line. Should warm weather pre- 
vail for a few days a few of the non-divers, as green- 
winged teals and mallards, will work back to old feed- 
ing grounds if food is plentiful; in the same manner 
ringbills, of the divers, appear here and there upon 
the lakes and wooded sloughs of the Mississippi bot- 
toms, a degree or two above the frost line. 
