- for courtship
- to mark the changeover of responsibility for nesting duties
such as incubating or feeding
- to practice and perfect songs
Usually, birdsong is not composed of randomly produced
sounds. Songs are exceptionally diverse melodies of specific mean-
ing, sung for a purpose, and are much more complex than the calls
used for signaling. They are generally used by males to advertise
and defend a territory, or in courtship. It is also believed that songs
serve a social function. When a pair is building their nest, they also
establish communication by song. Experiments on caged birds have
also demonstrated that birds find it easier to learn songs if another
bird is present, but out of sight, in another cage.
27
Male and female songbirds have different brain structures, par-
ticularly in the regions related to sound production. With many
songbird species, the males can sing, but the females cannot. The
males use “song” to call their mates or designate a tree, pole, or elec-
trical cable as a place to perch. Each species sings a song with its
own characteristics, but any given species’ songs display variations
64
