Spring flocks

Yesterday as I was walking along the Mississippi river near my home (it’s just a couple of streets away), I saw two huge black birds flying overhead. They turned out to be a pair of turkey vultures, & they were wheeling & swooping over the river, close enough that I could see their bright red naked heads & black feathers. Evidently there was an appetizing bit of rotting flesh down there. Vultures have naked heads because it keeps them clean when they feed. If they had feathers on their heads the feathers would get very dirty when they fed, & possibly make them sick. These birds have, lately, become common around here. Turkey vultures must get something from the river they can’t get elsewhere; whenever I see them, they are heading to the Mississippi.

A few days ago I looked out my window & there was a Common Grackle at the feeder. These shiny black birds are hard to miss, they are at least twice as large as other common feeder residents, such as finches & chickadees. They will eat sunflower seeds, but they seem to scare the other birds away. When a grackle’s in my yard, it’s the only bird there. Brown-headed cowbirds seem to be getting more numerous too. I don’t see them that often, but every few years there’ll be a spring where they’re all over. What’s interesting is that when that happens, common grackles start to appear more too.

The house finch that was at my feeder a few days ago has come back, & he brought his girlfriend with him. I see them almost every day now. The female isn’t terribly colorful, & I often mistake her for a sparrow, as she has no red, but the pattern of stripes on her back is different, & she’s almost never without her mate. I also recently saw an American Goldfinch. I have never seen one in MN before, although they’re supposed to live all over America. They are tiny but beautiful birds, with their neon yellow feathers & black markings. The one I saw was such a bright color, I could barely see it in all the yellow-green leaves of the just-blooming trees.

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Cowbird sighting

Today I saw a brown-headed cowbird looking for food with some sparrows. They are a bit larger than the sparrows, maybe by an inch or so; the male has a brown head, & a glossy black body, & the female is grayish-brown all over. Brown-headed cowbirds are North America’s most infamous brood parasite. They don’t build their own nests, incubate their own eggs, & rear their own chicks, instead, brown-headed cowbirds have a developed an alternative breeding strategy. The females use other birds as hosts – they lay their eggs in nests of other bird species and rely on those birds to incubate and raise their young. It has been discovered that brown-headed cowbirds have parasitized more than 220 host species, such as the black-capped vireo, blue-winged teal, & red-headed woodpecker. However, not all host birds make good parents – a number of birds will toss the cowbird eggs out of  their nests upon finding them, because brown-headed cowbird eggs can look distinctly different from the eggs of their host species. Still, brown-headed cowbird chicks have been raised successfully by more than 150 host species (which is less than 3/4 of the birds they try to get to raise their young), & songbirds make up most of their hosts.