76 FRIENDS OF OUR FORESTS 
not the purpose, of keeping the individ- 
uals of the assemblage in touch with each 
other and with the flock as a unit. Ina 
few moments silence again reigns where 
all was commotion and activity. The 
birds have passed on their seemingly aim- 
less course. 
If the observer would learn the solu- 
tion of the mystery of the birds’ evident 
hurry, he has only to follow them for a 
time, when he will find that, however er- 
ratic may seem the course of individual 
members of the flock, the flock as a whole 
is steering a tolerably straight course 
southward. In other words, he is in the 
midst of a flock of birds en route to their 
winter quarters and, in order to econo- 
mize time, feeding as they go. This, 
however, is not the only way warblers 
migrate, nor is it the most important, 
since the greater part of the long journey 
of many is performed by night. 
Any one with good ears has only to 
listen on a clear, frosty night in fall to 
hear hundreds of warblers and other 
birds as they flit by, a few hundred yards 
above the earth, the call notes coming in- 
cessantly out of the darkness. The route 
of these flying hosts often carries them 
above cities, and one cannot be insensible 
to the incongruity between his surround- 
ings and the woodland scenes, so vividly 
brought to mind by the lisping notes com- 
ing from the darkness overhead. The 
subject of migration has not inspired our 
poets so often as might be expected, but 
Longfellow, in his “Birds of Passage,” 
gives us the following wonderfully sug- 
gestive lines: 
But the night is fair, 
And everywhere 
A warm, soft vapor fills the air, 
And distant sounds seem near; 
And above, in the light 
Of the star-lit night, 
Swift birds of passage wing their flight, 
Through the dewy atmosphere. 
I hear the beat 
Of their pinions fleet, 
As from the land of snow and sleet 
They seek a southern lea. 
T hear the cry 
Of their voices high, 
Falling dreamily through the sky, 
But their forms I cannot see. 
Probably because insects constitute 
such an important part of their food, 
- 
warblers, as a rule, migrate early in fall 
and late in spring. It is true that in fall 
many linger till frosts nip the vegetation; 
but insects are abroad even later than 
this, and it is only necessary to watch 
these late migrants for a short time to 
learn that their search for insects is be- 
ing well rewarded. 
Only a few species come north early 
in spring, the great bulk of the warblers 
evidently having been taught by bitter ex- 
perience that in spring, at least, it is not 
the early bird that finds most worms or 
finds them easiest. 
FLOCKING OF SMALL BIRDS 
Just why small birds, when migrating, 
congregate in large flocks and troop 
through the woodlands has often been the 
subject of speculation. Juncos, several 
species of sparrows, woodpeckers, nut- 
hatches, chickadees, creepers, and, above 
all, warblers, combine to swell the ranks 
of these migrating companies. As many 
as a dozen or more species of warblers 
may often be seen in one flock, which, in 
addition, may include 200 or 300 indi- 
viduals, representing a number of fam- 
ilies whose tastes and habits in every-day 
life differ very widely. 
Yet here are these incongruous ele- 
ments mingling together on terms of the 
utmost friendliness. Since birds are so- 
ciable beings, except during the short 
time when family cares prompt to jealous 
vigilance, sociability alone may be the 
bond of union; added, however, to the 
kindly feeling of companionship probably 
is a feeling of increased security which 
comes from numbers. Certainly no enemy 
can approach one of these bird assem- 
blages without being spied by at least one 
pair of vigilant eyes, when the flock 1s 
immediately notified by a few sharp 
chirps—warning for every individual to 
seek safety in flight or to scurry to cover. 
WHAT MYSTERIOUS SENSE GUIDES THEM 
IN THEIR LONG JOURNEYS? 
In what manner warblers migrate— 
that is, how they are guided on their long 
journeys—is a moot question. Little 
mystery attaches to their ability to find 
their way north or south in daylight, 
since the recognizable landmarks are 
