Brood parasite is such an ugly pair of words. Birds who practice this form of raising their young are almost universally hated. That one bird species would survive by killing another seems so unfair, even though that is what predators do by definition. But it is what it is, and I finally got some pictures of a Brown-headed Cowbird (
Molothrus ater) so we 'll be mentioning it today.
If you haven't heard of it before, brood parasitism is the reproductive strategy by which a species of bird lays its eggs in the nest of another species, forcing the victim species to raise the nestlings as one of their own. The Cowbird eggs tend to hatch earlier than their victims and the chicks grow faster. As such they can destroy the other eggs, or push the other nestlings out. The Cowbirds have laid eggs in the
nests of some 220 other species.
Brown-headed Cowbirds are certainly a native species, long a part of the ecosystems of North America, but they have increased their range with the expansion of agriculture. This has happened because they prefer open fields where grazing animals disturb insects that can then be captured and eaten.
I finally got my first clear look at a Cowbird in an unlikely place, in the middle of the Mojave Desert at Hole in the Wall Campground. They are far more common back home in the Central Valley, but I've always managed to miss them in the large flocks of blackbirds with whom they tend to hang out.
I dunno, do you think people would like them better if we thought of them as unfortunate children who were abandoned by their parents, and they just need our understanding?
