The Nature Writers of Texas

The best nature writing from the newspaper, magazine, blog and book authors of the Lone Star State . . .

Sunday, January 01, 2006

Red-winged Blackbirds, A New Yardbird
by Ro Wauer

Redwings are abundant this time of year, usually in huge flocks, and often occurring in mixed flocks of blackbirds, including cowbirds and grackles. So, seeing one of these birds in my yard on Christmas morning was hardly a surprise. But when I checked my comprehensive yard bird list, lo and behold it was a new one, bringing the total list of yardbirds to 175 species.

The red-winged blackbird is sexually dimorphic, that is the plumage of males is different than that of females. Adult male redwings are all-black except for a bright red shoulder patch. Adult female redwings are dark brown and heavily streaked with whitish lines on the throat and chest and an eyeline. During the nesting season they frequent wetlands, especially areas of cattails, but in winter they can be found almost anywhere. Although they roost in cattail areas when available, oftentimes in huge flocks, they leave each morning for open fields and pastures where they feed on seeds and insects that might be available. One of the largest flocks recorded was one in Virginia that was estimated at 15 million birds. And they are known to fly miles from a roost to choice feeding grounds.

Redwings are members of the Icteridae Family that includes all the blackbirds as well as meadowlarks, bobolink, and the orioles. Redwings are most closely related to the tricolored blackbird, a very similar bird that is found only in the Central Valley of California. And the Brewer's blackbird, most like a common grackle, is also present in our area in winter. Brewer's usually occur in separate flocks, and most often are found along the edge of highways. The yellow-headed blackbird, another wintertime blackbird in Texas, can sometime be found in redwing flocks. And yet an additional blackbird - the rusty blackbird - that nests far to the north throughout most of Canada, is another wintertime blackbird, although it is rare in South Texas.

Although redwings flock in winter and are rarely territorial then, it is not uncommon to find separate flocks of males and females. But males become territorial on their breeding grounds. While several pairs may utilize the same wetland, males can be especially territorial. And they also are usually polygamous; one male mating with several females while one female will mate with only one male. Avian biologists tell us that it is the female that chooses its mate, selecting a superior male, probably one that defends a high-quality territory. When males are already mated, the female can choose either an inferior male or a male with a superior territory and is most likely to benefit the population. More often than not, in spite of the male being already mated, she will choose the best territory.

Another interesting facet of redwings is the male's very noticeable visual display, flashing its bright red shoulder patches. Courtship behavior often includes hovering while flashing his wings. Or from a perch, he will lean forward, droop his wings, spread his tail, fluff his body feathers, and raise his shoulder patches. That and his loud and distinct songs are sure to signal to all the available ladies that he is willing to take on as many members of a harem as possible. However, when researchers paint the red shoulder patches black so the red flashes are no longer are available, within minutes neighboring males invade and take over his territory.

My redwing yard bird was only a female that had come to one of my birdbaths. She did not possess the bright red shoulder patch, nor did she exhibit any territorial behavior. She sat very still, seemingly waiting her turn to drink amid a dozen robins that had gathered around the small water hole. She stayed only a few minutes before flying off, probably to join a nearby blackbird flock and head for the open fields nearby. She is welcome back whenever she wishes.

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