Thursday, September 02, 2004

Musings at the red light...

While I waited for the traffic light to turn green, I noticed a BIG flock of starlings in the grass next to my car. The first thing I noticed is that the
starlings all have their winter plumage, consisting of plain brown, white spots, and brown bills (as opposed to their summer plumage of iridescent black feathers and yellow bills).

Then I saw the three cowbirds mingling with the flock. At first I thought nothing of it besides, "Ah, I see cowbirds live in the area".

But as the light turned green and I pulled away, I remembered that cowbirds reproduce by laying their eggs in other birds' nests. If the foster parents don't detect the intrusion and abandon the nest altogether, the invading chicks hatch first and push the other eggs out of the nest. Then the foster parents raise the cowbird chicks as their own.

That left me wondering if the three cowbirds were not simply mingling with a flock of starlings. I wondered if the cowbirds had been raised among, and by, said starlings. Food for thought on a Thursday morning.

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