Monday, March 23, 2009

Bird Soap Opera

About an hour before sunset on Saturday, it was still warm, so Lilly and I went to the 135-acre Spring Valley to do some walking, instead of going directly home after various errands. The trails are still mostly brown and gray, but flavored with an anticipation of Spring. Maybe it was the birds that added that flavor.

One kind of bird in particular, the red-winged blackbird. I can't say we were birding, since birders go looking for birds, which may be fun for some. But at Spring Valley, these birds were highly visible. We spotted one perched on a small bare tree near the trail, making a lot of noise. All-black plumage with a shoulder patch of orange: I speculated that it was a mark of rank in the Bird Air Force.

The Cornell Lab of Ornithology says that "one of the most abundant birds in North America, the Red-winged Blackbird is found in wetlands and agricultural areas across the continent. The black male can hide the brilliant red shoulders or show them off in a dazzling display. The striped female looks strikingly different than the male and could almost be mistaken for a large dark sparrow."

Then we noticed another one in another tree, and a third in yet another tree, and then others in further trees. All of them were making a distinctive call. Once you noticed the call, it was hard not to hear it. So I figure we were walking through a vast patchwork of territories during early mating season.

Cornell adds that mating is complicated indeed among these birds: "The Red-winged Blackbird is a highly polygynous species, with one male having up to 15 different females making nests in his territory. In some populations 90% of territorial males have more than one female. But from one quarter to up to half of the young in 'his' nests do not belong to the territorial male. Instead they have been sired by neighboring males."

So it wasn't the Bird Air Force. It was a Bird Soap Opera.



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