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Natural Resources Council of Maine

Protecting the Nature of Maine

Creature Feature: Red-winged Blackbird

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    Red-winged Blackbird perched on branch with green leaves

    Red-winged Blackbird by Jayne Winters

    Red-winged Blackbird

    Agelaius phoeniceus

    Cool Fact: Red-winged Blackbirds can reach flight speeds up to 30 MPH and will travel as far as 50 miles to feed, returning to their roost at night.

    After last month’s feature about spring peepers, it seemed fitting to recognize another species that’s a harbinger of spring: the Red-Winged Blackbird. Its unmistakable call starts with a harsh, loud opening check followed by a high-pitched whistle, terrr-eeee. Although usually heard in marshy areas, ponds, or along slow-moving streams, you may also see them in grassy areas, open fields, and lightly wooded forests.

    Found in most of North and Central America, it breeds from Alaska south to Florida and Mexico, wintering as far north as Pennsylvania and British Columbia. Loose flocks can number in excess of a million birds; breeding pairs may peak at 250 million. They’re one of the most common birds in the eastern US and are in the same family as grackles, orioles, and cowbirds.

    Swedish scientist Carolus Linneaus gave the Red-winged Blackbird its scientific name in 1766, from the Greek words for “gregarious” or “flocking” and “crimson” or “red,” respectively. Its common name comes from the brilliant red shoulder patches (epaulets) on the glossy black adult male. These markings not only attract females, but research has shown that males with larger red patches are more effective at chasing away predators and territorial rivals.

    About the size of a robin, it has a long, slender, sharply pointed bill and a medium-length, rounded, square-tipped tail. The female is streaked dark brownish, paler on the breast, and often shows a whitish eyebrow, to provide camouflage while sitting on the nest. She’s smaller than the male at 6.5–7” long and weighs about 1.5 oz; the male is 8.5–9.5” and weighs up to 2.9 oz. Their eyes, bill, legs, and feet are black, except the female’s bill is dark brown and clear at the bottom of the top half. Young birds resemble the female and acquire adult plumage after their first breeding season; the average lifespan is three-and-a-half years.

    They’re opportunistic foragers, so their diet is varied — mostly insects, seeds, berries, and small fruit — but they’ve also been known to eat snails, frogs, worms, and even carrion.  Experiments have shown that if a companion eats something that makes them sick, other birds will avoid that food, even without having taste-tested it themselves. They even wipe insects on the ground to remove dirt before eating them!

    Red-winged Blackbirds are territorial and aggressively defend their home turf, often attacking much larger birds, animals, and even humans. Their reproductive season is typically late April to early August, and they often create nest colonies in cattails, bulrushes, tall grasses, or bushes. The female is in charge of nest-building, making a basket of grasses and moss, lined with mud, and securing it to supportive branches and grasses. She’ll lay three to four pale bluish-green eggs that have brown, black, and/or purple markings around their larger end. Incubated only by the female, the eggs hatch in 10-12 days, and youngsters will leave the nest within 14 days. Pairs raise two to three clutches per season, with a new nest for each batch. Only about one-third of the nests successfully produce chicks. Nest predators include foxes, raccoons, weasels, mink, snakes, hawks, and other birds — some as small as Marsh Wrens.

    Red-winged Blackbirds are a polygynous species, meaning males have multiple female mates, up to 15 in some cases! However, studies report that as many as 25-50% of nestlings were sired by someone other than the territorial male. Although he’s the male who raises the chicks, some of them may not be his own. (Who knew birds could be step-parents?)].

    Although their numbers have fallen 36% since 1966, Red-winged Blackbirds are considered a species of least concern because of widely distributed populations. They are protected under the Migratory Bird Treaty Act, but destruction of wetlands obviously will continue to have a serious impact.

    More “Cool Facts”

    • When migrating, they stay in their flock and fly only in daylight, so they won’t get disoriented by artificial lights and can better see buildings and turbines.
    • Red-winged Blackbirds rank among the best-studied wild bird species in the world.
    • There are 22 subspecies, varying significantly in size and proportions. An experiment in which nestlings were moved between different populations found they grew up resembling their foster parents, indicating some population differences are more influenced by the environment in which they’re raised compared to the make up.
    • Websites differ on the age of the oldest recorded Red-winged Blackbird: one states 20 years, 3 months; another cites one that was banded in NJ in 1967 and found injured in Michigan in 1983 (it was released after recovering from its injuries).

    Written by Jayne Winters – April 2026

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