Birds
Red-winged Blackbird
Agelaius phoeniceus · also called redwing
The red-winged blackbird is one of the sounds and sights that says spring has arrived across most of North America: a glossy black bird tilting on a cattail, flashing red shoulders, and pouring out a loud, gurgling song. It is also, by many counts, one of the most abundant birds on the continent.
Overview
Agelaius phoeniceus breeds in marshes, wet meadows, and ditches across North America and winters in open farmland, often in flocks of millions. The male is black with red-and-yellow shoulder patches; the female is streaky brown and often mistaken for a sparrow. It eats insects in summer and seeds and grain in winter.
The badge it can hide
The red patches signal ownership and strength. A male on his territory shows them fully; a male crossing another’s marsh covers them with black feathers to avoid a fight. Painting a resident male’s patches black causes him to lose his territory — the classic proof that the badge is what keeps rivals out.
Aggressive and unfaithful
Males dive-bomb hawks, herons, and people near the nest. A good male may hold 5–15 females’ nests, yet DNA shows a quarter to a half of chicks are fathered by neighbours.
Status
Least Concern but declining by about 30% since 1970, and killed in numbers where winter flocks raid grain crops.
Red-winged Blackbird: common questions
Why does a red-winged blackbird sometimes hide its red patches?
The red-and-yellow shoulder patches are a signal of ownership and fighting ability, and showing them has a cost as well as a benefit. On his own territory a male displays them constantly, spreading the wings and puffing up to make the red as visible as possible, which warns rival males to stay away and attracts females. But a male that needs to cross another male's marsh, to reach a feeding area or a second territory, covers the red with the black feathers around it and slips through quietly, because a visible red patch in someone else's territory is an invitation to be attacked. The bird effectively has a badge it can switch on and off.
Will a red-winged blackbird attack me?
In spring and early summer, near a marsh nest, quite possibly. Male red-winged blackbirds are among the most aggressive nest defenders of any North American songbird, and they do not distinguish much between a genuine threat and a person simply walking along a trail near the cattails. The attack is a fast dive from behind, sometimes with a strike to the head from the feet, accompanied by sharp alarm calls, and it is repeated until the person moves on. It is startling but essentially harmless, and it stops as soon as you are clear of the nest area and once the young have fledged.
If they are so common, why are red-winged blackbirds declining?
Abundance and trend are separate things. A species can number in the hundreds of millions and still be losing ground, and long-term monitoring shows red-winged blackbird numbers have fallen by around 30 percent since 1970, part of a broad decline across North American grassland and marshland birds. The suspected causes include the draining and degrading of wetlands, the loss of the insect prey that chicks depend on because of intensive farming and pesticides, and the direct killing of the birds where winter flocks damage sunflower, corn, and rice crops. The decline is gradual enough that the bird still seems everywhere, which is part of why it gets little attention.
How do you tell a female red-winged blackbird from a sparrow?
Female red-winged blackbirds are heavily streaked brown and buff and look nothing like the glossy black male, so they are frequently reported as large sparrows or as an unknown bird. Clues are the size, clearly bigger and longer-billed than a house sparrow or song sparrow, the sharply pointed bill, a pale eyebrow stripe, and often a faint reddish or salmon wash on the shoulder and throat. Behaviour helps too, since female red-wings clamber about in marsh vegetation and feed on the ground in flocks with males, rather than hopping in hedges and at feeders the way sparrows do.