VOICE OF BIRDs. 63 
is a most welcome promise of spring. Then follow the 
Robins, Blackbirds, and other migrants, until, late in 
May, the great springtime chorus is at its height. 
The Bobolink is the first bird to desert the choir. 
We do not often hear him after July 5. Soon he is fol- 
lowed by the Veery, and each day now shows some fresh 
vacancy in the ranks of the feathered singers, until by 
August 5 we have left only the Wood Pewee, Indigo 
Bunting, and Red-eyed Vireo—tireless songsters who 
fear neither midsummer nor midday heat. 
Call- Notes—The call-notes of birds are even more 
worthy of our attention than are their songs. Song is 
the outburst of a special einotion; call-notes form the 
language of every day. Many of us are familiar with 
birds’ songs, but who knows their every call-note and 
who can tell us what each call means? For they have a 
meaning that close observation often makes intelligible. 
Listen to the calls of the Robin and learn how unmis- 
takably he expresses suspicion, alarm, or extreme fear; 
how he signals cheerfully to his companions or gives the 
word to take wing. Study the calls of the Crow or Blue 
Jay, and you will find that they have an apparently ex- 
haustless vocabulary. 
It is supposed that birds, like men, do not inherit 
their language, but acquire it. Thus there are recorded 
instances of young birds who had been isolated from 
others of their kind, learning to sing whatever song they 
heard. On the other hand, it is said that a bird inherits 
its own notes, at least to some extent, and, while it may 
not sing the song of its species perfectly, its song will 
still be sufficiently characteristic to be recognizable. 
There are, however, very few satisfactory observations 
on this subject, and keepers of cage-birds have here an 
excellent opportunity for original investigation. 
