n.
Certain vocalizations of birds, characteristic of males during the breeding season, for the attraction of a mate and for territorial defense.
Birdsong also reinforces pair bonds, and some species have a flight song. Birdsongs are usually more complex and longer than birdcalls, which are used for communication within a species. Birdsong may be hereditary or learned; a newly hatched male chaffinch , for example, can sing a "subsong" but must learn to sing the true song by listening to and imitating adult males.