Brooklyn Bird Watch: June 30


Photo by Heather Wolf.

Today, Brooklyn Bird Watch features an excellent Heather Wolf photo of the male Red Winged Blackbird. On August 23, of last year Brooklyn Bird Watch featured Ms. Wolf’s photo of the female Red Winged Blackbird. It appears she finally got a shot of the male, and it’s a good one.

In Ms Wolf’s new photo the male bird is perched on the edge of the nest, probably having just delivered some food to the female. One also gets a good glimpse of the fascinating nest structure. Building a nest like that requires the female to wrap and tie secure flexible strips of whatever-that-is to the marsh reeds, then use those strips through which to cross weave vegetation to create the bottom of a cup structure to hold the eggs.
So the females “build the nest by winding stringy plant material around several close, upright stems and weaving in a platform of coarse, wet vegetation. Around and over this she adds more wet leaves and decayed wood, plastering the inside with mud to make a cup. Finally, she lines the cup with fine, dry grasses.”

Generally, people probably don’t know that many twig based bird nests are designed to be elastic and actually expand as the chicks grow. By the way, birds are not taught to build a nest, the skill comes from a combination of instinct and learning from elders. Many birds of the same species have different building techniques, depending on their experience. To read something interesting about bird nest building, click here.

Some say that the Red Winged Blackbird is the most abundant land bird in North America. Wikipedia says that the Red Winged Blackbird is the “best studied wild bird species in the world.” The male is all black with a striking red shoulder and yellow wing bar, while the female is a nondescript dark brown. Seeds and insects make up the bulk of the red-winged blackbird’s diet.

And speaking of polygamy, the fundamentalist Mormons don’t have anything on the Red-winged Blackbird. According to Cornell, it is a highly polygynous species, meaning males have many female mates. In some populations 90 percent of territorial males have more than one female nesting on their territories. Audubon says the Red Winged Blackbird “usually nest in loose colonies, with a male attracting up to 15 females to nest within the territory. And yet it is also more complicated than it sounds: “one-quarter to one-half of nestlings turn out to have been sired by someone other than the territorial male.”

With that many wives, so to speak, it stands to reason that the male Red-winged Blackbirds must spend a lot of time and energy getting noticed, as Cornell notes, they sit on high perches belting out their song all day. Females on the other hand, stay lower, stealthily moving through vegetation for food and “quietly weaving together their remarkable nests.” The female skillfully weaves the nest, as Audubon describes it: The nest is placed in marsh growth such as cattails or bulrushes, in bushes or saplings close to water, or in dense grass fields. The nest is a bulky, open cup, lashed to standing vegetation, made of grass, reeds, leaves, and lined with fine grass.”

In winter Red-winged Blackbirds gather in huge flocks to eat grains with other blackbird species and starlings. They roost in flocks in all months of the year. In summer small numbers roost in the wetlands where the birds breed. Winter flocks can be congregations of several million birds, including other blackbird species. Each morning the roosts spread out, traveling as far as 50 miles to feed, then re-form at night.

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