Bird watching: why do birds sing in autumn?

Self-tutoring about birds: the tutor mentions autumn singing.

We’ve had a rainy, stormy fall — hard to believe, and somewhat of a relief, after the past summer’s unbelievable heat. However, between the rainy, stormy episodes have been a few nice sunny days. No matter what, the temp stays 12°C or lower nowadays.

At one of these fine, sunny times, when I’m outside, the birds sing up a storm. Numerous kinds, in the same yard, broadcast their songs energetically, seeming to want everyone to notice. They’re not getting ready to mate, so why put on such a flirty, bold, fun show?

Apparently, non-migratory birds, in the fall, may sing to proclaim their territory. Greeting is also a function of singing.

Source:

birds.com