As I get older, it seems that winters get longer and colder. I know that’s not true, but sometimes it sure seems that way! Each year, a little earlier, I start thinking about spring and longing to hear the dawn chorus of the birds waking up from winter.
In North America, the American robin is one of the most audible and common participants in the dawn chorus, with many other singers joining in the concert. They sing to attract a mate and also to establish breeding territories. The chorus may start as early as 4 a.m. and extend several hours until the sun has risen and temperatures begin to warm.
There are several reasons why birds choose to sing early in the day:
Showing off one’s vocal prowess early in the morning demonstrates that the singer is strong and healthy enough to survive a night of dipping temperatures and active predators, helping to attract a mate.
Other competing sounds like insect buzzing, car traffic, or construction are less common in the early morning hours so their song is less likely to be drowned out by ambient noise.
Lower morning temps and fewer air currents permit a bird’s song to travel farther without as much interference or losing strength, helping the bird to use its song to claim or defend a territory or advertise its presence to prospective mates.
Early morning light levels are too low for foraging and insects are not yet active for feeding. With fewer other activities to choose from, early morning is an excellent opportunity for birds to sing.
These are all good reasons for the birds to sing in the morning.
Me, I just enjoy listening.