It's Spring, and no doubt you've heard the birds engaging in one of their favorite pasttimes-singing . Hi, I'm Dave Thurlow and this is the Weather Notebook. It turns out, there are biological reasons for this seasonal rise in avian song. Correspondent Jeff Rice files this report.
Birdsong is as much a part of spring as flowers and romance.
The warmer weather with more food signals to birds that it's a good time to start a family. So the males start warbling their love calls in earnest. But there's another reason that the air is filled with song and it has to do with light and chemicals. Biologist Stephen Hopp of the University of Arizona says more light affects key chemicals in birds. The day-length increases the testosterone in males which changes the structure of his brain which increases the amount of singing.