When Anna's hummingbirds sing is it really a song?
It’s September. Summer birds are rapidly departing for more accommodating climates. The first of our winter visitors are making their way south from Alaska and down from the mountains to check out backyard feeders in the valley.
The time for song is over. Well, almost. Stepping out on the back porch in the morning, cup of coffee in hand, I can still hear collared doves singing in the distance at times. Do they ever stop? Given how fast their numbers increased in the valley over the last decade or so, they surely rear several broods a year. Even in September they appear to be trying to squeeze in one more nesting.
Then there is the ever-present Anna’s hummingbird. The high-pitched squeaky song is a daily fixture. The male sits on a prominent perch providing an unobstructed view of the feeder and belts out its thin but insistent song. I’m sure the birders out there can hear the song in their mind.
Now try to recall the song of the rufous hummingbird, or calliope, or Allen’s or any of the other hummingbirds found in the western United States. It can’t be done. The Anna’s hummingbird is the only hummingbird in the region with a song.
Why should the Anna’s be the only hummingbird with a song? Males of all species, including the Anna’s, have a spectacular display flight used in courtship involving pops and whines produced by vibrating feathers as they dive over the heads of prospective mates. So, they haven’t traded display flights for song.
The Anna’s hummingbird is the only western hummingbird that doesn’t migrate. So, does being a resident make a difference? But then I think of all the impressive songsters of other species now on their way to Mexico. This puzzle requires more thought.
But then, does their “singing” even involve songs? I am often asked, what is the difference between a song and a call? The traditional answer is that songs are associated with breeding, and calls may be heard in many other circumstances and at many other times of the year. The mountain chickadee provides a perfect example. The “cheese-burger” song is heard only in the breeding season, while the “chick-a-dee-dee” call can be heard any time of the year.
As for the Anna’s hummingbird, it is now September. The breeding season is long over. They start with the early blooms of March and fledge their young by May. So, if they are singing in September, this cannot be a song. Right?
But then, their singing does appear to serve a territorial function, something usually associated with breeding. Just let another hummingbird approach the feeder, and there will be a quick challenge by the singing male involving chases if not fights. So, songs advertise territory and have little to do with the female when breeding? Yes, but in species like the hermit warbler, males have two distinct songs, and one is clearly targeted at the female.
Now I’m really confused. This is going to require a second cup of coffee, maybe a third. For now, I give up. Until someone can convince me otherwise, I will continue to enjoy the singing of Anna’s hummingbirds on a September morning.
Stewart Janes is a biology professor at Southern Oregon University. He can be reached at firstname.lastname@example.org.