Tuesday, February 3, 2009

Mystery date

If you're checking back for the Temple Grandin post, I swear it's coming--Friday, probably. Meanwhile, I'd like to talk about woodpeckers; specifically, the quartet of pileated woodpeckers I watched in the park on Sunday. Their courtship season is underway, so the woods are filled with the sound of territorial drumming. There's plenty of calling and chasing, too, inspired by anger as well as desire. Pileateds, like most woodpeckers, are very contentious when they're mating and nesting.

Everybody gets in on the fighting, but males really mix it up, and will go on battling for a long time. It's fun to watch. When a male flew over my head on Sunday, repeating a loud, aggressive squawk, I thought I was about to see a serious woodpecker smackdown, but it was a female--clearly his mate--who answered his call and followed him to the oak tree where he had settled. He commenced calling again after she joined him, and then, strangely, a second mated pair showed up. They both answered him and went to the same tree. He took flight again, and the whole process was repeated. His own female followed him, then was followed in turn by the second pair. They kept this up for at least ten minutes, changing trees five or six times.

I've never seen mated woodpeckers behave that way. Each couple usually has a territory that they defend vigorously. Outsiders are regarded as threats to monogamy and are not tolerated. Woodpeckers do feed together in family groups, but I feel sure that these were all mature birds. I went hunting through my bird books and the Internet, looking for an explanation, but couldn't find anything really definitive. One ornithologist (see below) did describe something similar, which he interpreted as a border skirmish; i.e., birds confronting each other in an area that didn't really belong to any of them. He's the expert, but what I saw didn't look like a dispute of any kind. It looked distinctly friendly. It seemed like a form of socializing, a sort of double date.

I like the fact that I can't be sure what they were doing. I always get a lot of pleasure out of encountering odd behavior in animals. I like the ambiguity, the uncertainty--which I suppose means I'm not much of a naturalist. I don't have that scientist's compulsion to decipher the world down to its last detail. Mystery delights me.

Still, there's something to be said for delving into the details and making careful observations. Here's an account by the same ornithologist of woodpecker love. For some reason I find it completely charming.

"At 8:40 a.m. on the following day I had a more complete view of copulation when the female alighted near the male. An exchange of woicks followed. She was again crouching crosswise on a limb when he flew over and mounted her back firmly. He then fell backward and over to the left in a gradual and awkward fashion in what appeared to be close cloacal contact. This process took an appreciable time. The female presented an odd spectacle after he had left, for her head and tail were drooping limply over either side of the limb and her body was flattened closely against it."

From "Behavior and Methods of Communication of Pileated Woodpeckers," Lawrence Kilham, The Condor, v.61, n.6 (Nov.-Dec., 1959), p.380. [You can find this article at SORA Searchable Ornithological Research Archive.]

Woodpecker tapestry by William Morris (detail), image from Wikimedia Commons. (I know this is an unseasonable picture, and I don't even know what kind of woodpecker it is, but it was too pretty not to post.)


Bozo said...

Would Kilham be a pornithologist? Yuk, yuk.

whodat said...

Wife-swapping woodpecker couples! What will they think of next?!

Olfacta said...

Yes, birds getting ready for spring! I've seen bluebirds, which are unusual in the city, and finches looking for nesting sites. Spring is coming. It can't get here too soon this year.

BitterGrace said...

Sorry I'm so slow to say thanks for the comments. I hate it when real life gets in the way of virtual friendship ;-)

I must say, I am a little curious about Mr. Kilham, Bozo. He was/is quite the expert on woodpecker love, and everything else to do with the species. I wonder if he's still around.

Who said anything about wife-swapping, Whodat? I'm sure it was all very respectable.

Olfacta, even though it's very cold here right now, our bluebirds are courting, too. Everybody seems to be at it a couple of weeks early--including the skunks.