Friday Feathered Feature
Showcasing a different bird species each week
White-striped white-throated sparrow, photo by USFWS Midwest
“Old Sam Peabody body body body.” So the song goes. It was the first bird song mnemonic that I learned. I learned it while up north, on Wisconsin's Long Island on the shores of Lake Superior. It took me an embarrassingly long time to figure out that song. As I monitored the endangered piping plovers on Long Island's sandy shores, the white-throated sparrows seemed to follow and mock me. I had uncovered the identity of the white-throated sparrow, but as it turns out the bird's identity is much more complex than its name.
These sparrows exhibit polymorphism, with four possible identities that they assume for life. Males and females may be either white-striped or tan-striped on their crown. These differences in phenotype have huge implications for the sparrows, and shape their social interactions and even habitat selection.
White-striped birds will aggressively defend the nest, sing much more frequently, and the males will copulate with multiple female partners. White-striped females will copulate multiple times with their male counterparts. The white-striped males' breeding territory includes more open forest canopy. For these reasons, the birds I heard on Long Island—which called all day amid the open pine forests, bogs, and dunes on the island—were almost certainly white-crowned males.
White-striped white-throated sparrow, photo by Kelly Colgan Azar
The tan male birds tend towards denser forested habitat, sing less, and spend more time on the nest taking care of young.
To complicate things, opposites attract in the world of white-throated sparrows. Females of both types prefer tan-striped males, and the aggressive white-crowned females will quickly pair with the tan-striped males. That leaves the white-striped males to mate with the tan-striped females. This is known as dissasortative mating, where opposite genotype/phenotypes mate more often than would be expected randomly. In white-throated sparrows, this mating maintains the polymorphism in about equal proportion of white-striped and tan-striped birds.
Tan-striped white-throated sparrow, photo by Kelly Colgan Azar
All of this information was gathered through simple ornithological research, conducted analyzing museum specimens and following hundreds of live birds. This simple research revealed intriguingly complex social lives in white-throated sparrows and allowed scientists to test for a genetic basis of the differences, which exists due to a chromosomal inversion.
You can find white-throated sparrows migrating through Faville Grove soon. They prefer some type of forest cover, but can be found in brushy edge habitat as well. These birds are recognizable as winter feeder birds during a Wisconsin winter, but at that time it's very difficult to tell the difference between tan-striped and white-striped birds. The simple and folksy song of the white-throated sparrow belies its remarkable life history, a truly fascinating discovery of science. You can read more about this bird in Ken Kaufman's Notebook, which delightfully delves into the nuance of different bird species and is accompanied by wonderful illustrations.
Written by Drew Harry, Faville Grove Sanctuary land steward
Header photo by Kelly Colgan Azar
Music without lyrics. Perhaps in the absence of voice is the beauty of the unkown, like in opera. Top 40 radio hits you over the head like a red-winged blackbird defending its nest, no subtlety.
I couldn’t find this bird. It woke me in the morning, made pancakes with me at dawn, exclaiming “DUMMYYY it’s burnt, it’s burnt, it’s burnt, it’s burnt.” The bird followed me as I walked along the dunes of Long Island; it put me to sleep at night and occasionally pierced the silence of those laughably early mornings and those sparkling Superior skies.
Of course, it wasn’t one bird’s call, though I imagined it as one bird, flitting through the forest following me around, lonely—a projection of myself. I tried to find the “DOOOO DEEE,” as I began calling it, without luck. It was unknown and mysterious. I called back, and the bird would return with its call, though I couldn’t be sure was returning my call.
So slow and melancholy, the call began, the first two syllables deeply felt, while the next verses were quick and playful in a folksy, nostalgic way.
There was no Google search to answer this question. Of all the billions of bits of information I could Google, this was not one.
A friend told me it was a white-throated sparrow. Sibley told me that the call goes “Old-Sam-Peabody-Peabody.” I laughed. I told myself that I now “knew” the bird. The mystery vanished. I felt I lost a companion.
But had the mystery vanished? I think not. For three months, I observed the inner workings of piping plover life, read all of the research on piping plover behavior, but I was far from knowing the plovers. Checking the white-throated sparrow off a list meant nothing. “The whistler of the North” does not sing to be greedily reduced to a checkmark, it sings for itself. To know a bird is to know the landscape where it lives, and to know a landscape is to know yourself. If anything, there were more mysteries and questions than before.
It’s important to remember during the hysteria of spring migrations and birdathons that these birds are more than checkmarks; they’re something to behold. The Canada Geese, Red-winged Blackbirds, and Killdeer may be dismissed as givens on any checklist, but they are here, living, thriving.
On Saturday Faville Grove will be hosting a number of talented birders, not including myself, for the Great Wisconsin Birdathon. According to ebird data, White-throated Sparrows passed through about a week ago, but maybe we’ll catch a straggler. If we do, my checklist will be ready, and I’m betting I’ll have more checks than Goose Pond.
Photo by Andy Reago & Chrissy McClarren, Flickr Creative Commons.
