UTILITY OF BILDS IN WOODLANDS. 103 
ever hunting, hunting, hunting, to find the wherewithal to 
stop those insistent, hungry cries; for hunger is not good 
for young birds, and their cries may betray them to their 
enemies. This continual search for food for the callow 
young goes far towards checking the uprising host of in- 
sects in June and July, and preventing the absolute destruc- 
tion of the trees. 
When the young birds are out of the nest, their parents 
lead them to some spot where insects are most plentiful, and 
there continue to feed them for a time. When the fledge- 
lings are strong and well able to fly about and find their own 
sustenance, the old birds usually drive them away from the 
vicinity of the home, and they scatter in search of food, 
drifting here and there, wherever food is most plentiful, 
until they find themselves moving southward, with the 
receding tide of bird life, toward that land where frost 
and snow are never known. 
Some of the Warblers are ready to leave for the south by 
midsummer. Such of the summer residents as still remain 
wander through the woods in late summer and early fall, in 
search of insect outbreaks, wild fruit, and seeds, feeding as 
they move along. They are now slowly migrating. The 
chill of autumn evenings accelerates their southward move- 
ment, and on clear, still nights their call notes and even 
their beating wings may be heard as they fly southward. 
The birds are now without home attachments, and gather 
wherever food is most plentiful. Those that have found 
insects in plenty call to others that are flying by or overhead, 
bidding them also to the feast. So the tide of bird life 
sweeps back through the woods of the temperate zone toward 
the equator. In late October bird songs are heard no more. 
A few Thrushes, Woodpeckers, Chickadees, Kinglets, Creep- 
ers, and Nuthatches flit here and there; Blue Jays mourn- 
fully call; a Crow caws now and then; but otherwise the 
_woods seem deserted. Still, at this season of the year and 
all through the winter and early spring months the few birds 
that remain are accomplishing the greatest good for the 
forest ; for now the development and increase of all insects 
are arrested, while their destruction. by birds goes on. In 
