Bird Songs In Your Back Yard
The typical song of a species of bird may be termed its territorial song, which is sung during the hour before sunrise. Listen some morning just to the Robin and Cardinal and see if you can define the differences yourself.
Another special song is the aggressive song, which is usually given when an excited male is involved in a territorial encounter. While most birds simply increase the cadence of their singing in such situations, species such as the Yellow Warbler, sing a different song pattern that betrays their aggressive mood.
During the height of courtship, a male may approach a female and sing an excited, continuous courtship song that often leads to copulation. My favorite courtship songs come from the Fairy Bluebird and the Shama Thrush. The Fairy Bluebird will perform a song just for the female that he is approaching. If she likes what she hears, she will respond by repeating the complex tones. This gesture will tell the male that it’s ok to mate.
A pair of birds singing together in a close knit fashion demonstrate song duetting. While this is common in tropical birds, it is rare in temperate zone birds. Some common species in Pennsylvania do show related forms of duetting. The Great Crested Flycatcher has been observed using a greeting ceremony which qualifies as duetting.
Singing can occupy a great deal of time. One Song Sparrow was observed singing for 9 hours in 24 at the height of the breeding season. Singing is usually closely tied to a certain light intensity. It peaks in the early morning then slacks off through late afternoon., when it again picks up. The Red-eyed Vireo, however, often sings more or less continuously throughout the day. It is called a “preacher bird” for its persistent, monotonous noise. It is a nuisance to the birder who is trying to hear other birds.