Thursday, April 17, 2008

Here, but NOT Welcome!

Oh, the hated brown-headed cowbirds are back. They return in the spring just before the songbirds that they parasitize so thoroughly. Here's a male (right) and female hoping to fatten up on cracked corn in our side yard.

I won't recount the entire natural history of the brown-headed cowbird, except to say that they evolved following roving herds of bison, eating the insects these large mammals kicked up. Being constantly mobile, cowbirds could not afford to build a nest, incubate eggs, and raise young. So they adapted to let someone else do all the work. Female cowbirds lay their eggs in the nests of other birds. They are amazingly good at finding hidden bird nests and waiting until the coast is clear to slip in and make an unwanted egg deposit.

Two weeks later the "foster" parents are raising a youngster that is not their own (and probably arguing over whose side of the family the nestling's ugliness comes from).

If it weren't illegal and bad for the soul, I'd consider doing something to control this species. Cowbird control measures have resulted in increased reproduction by the endangered Kirtland's warbler in Michigan.

Every year here on our farm we see fledgling cowbirds and it makes me heartsick to think of the wood thrushes, blue-winged warblers, and indigo buntings that were fooled into raising them.

One species that never has to raise cowbirds to fledging is the American goldfinch. Their nests get cowbird eggs to be sure, but the nestling cowbirds cannot survive on the goldfinches' all-seed diet.

Instead of "offing" cowbirds, we'll quit feeding so much corn and mixed seed (which the cowbirds love) and we'll curse these parasites whenever we see them.

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Tuesday, January 01, 2008

The First Bird of the Year

American goldfinch at the Indigo Hill feeding station.

Happy New Year, everybody!

My first bird of 2008 was an American goldfinch in winter plumage.

I could have waited around, blind-folded until Julie saw a less common species and led me to it—say a nice eastern bluebird, or a purple finch, or a red-breasted nuthatch—but when I cracked my eyes open for a few minutes at about 8:30 this morning, it was the GOFI that I saw.

This is a game I've played for a couple of decades. Some years I really try to get a "good" bird to start the year off. When I lived in New York City it was almost always a rock pigeon (then rock dove) or a house sparrow. One year I lucked out with a herring gull. In Baltimore, I could sometimes see the neighborhood American kestrel that roosted in the church steeple across the park from my apartment.

I did not see another bird today until about 2:45. I was sleeping to recover from a very late night last night. More on that later...

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