Brooklyn Bird Watch: Red-Winged Blackbird

Today, Brooklyn Bird Watch features another excellent Heather Wolf photo taken in Brooklyn Bridge Park of a female Red-Winged Blackbird.

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.

While many birds mate in pairs, Red-Winged Blackbirds are highly polygamous — one male may mate with up to 15 females. In some populations, 90% of territorial males have more than one female nesting on their territories. And yet, as Audobon points out, 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 so many wives, so to speak, it stands to reason that the males must spend a lot of time and energy getting noticed, which is probably why, as the Cornell Lab of Ornithology points out, they sit on high perches belting out songs 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.