Red-winged blackbird (Agelaius phoeniceus)

GenusAgelaius (1)
SizeLength: 18 - 24 cm (2)

The red-winged blackbird is classified as Least Concern on the IUCN Red List (1). 

The red-winged blackbird (Agelaius phoeniceus) is one of the most familiar of all North American birds, where it is known by many for the male’s unmistakable plumage and is thought of as a harbinger of spring (3). This species displays marked sexual dimorphism, the male red-winged blackbird being glossy black with conspicuous red and yellow shoulder patches. The smaller, drabber female is mottled dark brown above and crisply streaked below, with a prominent white eyebrow stripe, orangish throat and a pale breast. The juvenile red-winged blackbird is similar to the adult female, being overall dark brown with reddish edges to the feathers. Before developing adult plumage, immature males are highly variable in appearance, ranging from female-like brown with a heavily streaked breast, to black with brown flecks (4) (5). 

A stocky bird with a slender, conical bill and a medium-length tail, the red-winged blackbird is easily mistaken for the tricoloured blackbird (Agelaius tricolor). However, male tricolored blackbirds can be distinguished by overall glossier plumage and by a white border on the shoulder patches. Female tricoloured blackbirds are charcoal-grey overall, with less streaking than female red-winged blackbirds (5).

The red-winged blackbird occurs from south-eastern Alaska and Canada, south through the United States to the Gulf Coast, Central America and the northern Caribbean islands. The most northerly populations migrate southwards after the breeding season, but some populations in the western and central United States, Central America and Gulf Coast are known to be resident year-round (4).

During the breeding season the red-winged blackbird may be found in a variety of fresh and saltwater habitats, including in bushes and small trees along watercourses and marshes, as well as in dry meadows and agricultural areas. Whilst migrating, it may also be found in open cultivated fields, pastures and prairies (2) (5).

A gregarious species, the red-winged blackbird nests in crowded groups, low among vertical shoots of marsh vegetation, shrubs, or trees. It is a polygamous species, the male mating with several females that nest inside its territory. In some populations, 90 percent of territorial males have more than one female nesting on their territories. However, the females may also mate with more than one partner, and as many as one-quarter of nestlings may turn out to have been sired by a different male (4) (5). 

Prior to breeding, male red-winged blackbirds do everything they can to get noticed, sitting on high perches and belting out their “conk-la-ree” song all day long (5). Males may also chase after females with the shoulder feathers erected. Typically five or more females, sometimes up to 15, may crowd their nests into any one male’s territory. Females build the cup-shaped nests by winding stringy plant material around several close, upright stems and weaving them into a platform of coarse, wet vegetation. Between 2 and 4 eggs are laid, and are incubated by the female for 11 to 13 days. The male may help the female to feed the hatchlings while they are still in the nest, as well as for up to two weeks after they have fledged (4). 

The red-winged blackbird gathers into roosts throughout the year. During the summer months it congregates around the wetlands where it breeds, but during the winter it may share roosts with other birds, in groups that range in number from a few individuals to several million (4). Each morning the roosts spread out, travelling as far as 50 miles to feed, then re-forming at night (5). The red-winged blackbird eats seeds in the winter, including corn and wheat, and mainly insects in the summer. It uses its robust bill to open the leaf bases of aquatic plants and reeds, or to lift sticks and stones to expose hidden insects. It also picks up seeds and other items from the ground and gleans insects from vegetation (4).

With a global population estimated at an incredible 190 million individuals in 1974, the red-winged blackbird is perhaps North America’s most abundant native bird (4) (5). Populations increased spectacularly during the middle of the 20th century as a result of the conversion of marshes and woodland to upland pastures and grain fields, to which the red-winged blackbird has superbly adapted for nesting (4). 

Populations have increased to such great numbers in certain areas that this species is now considered by some as an agricultural pest, in part due to its fondness for feeding on cereal crops. It is also a threat around airports due to the risk of collisions. In these places, efforts are underway to cull the red-winged blackbird population (6) (7).

As an extremely abundant species, most management efforts targeting the red-winged blackbird have aimed to limit its numbers. Initially, this species’ damage to crops was limited by attempts to scare birds away with scarecrows, by banging on metal drums, or by firing shotguns. However, an amendment to the 1918 Migratory Bird Treaty Act, which previously protected the species from persecution, allowed farmers in the U.S. to kill red-winged blackbirds that threaten crops. 

Blackbirds may be killed by shooting, trapping, poisoning, or by spraying with surfactants, which are detergents that reduce the water-proofing and insulative properties of feathers, causing birds to die of exposure during cold weather. Campaigns using surfactants have been particularly effective at controlling red-winged blackbird numbers. Non-lethal management attempts have focused on reducing the availability of suitable breeding or roosting habitat (4), or have used frightening devices such as propane exploders, helium balloons, radio-controlled planes or tape-recorded distress calls of birds (7).

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  1. IUCN Red List (February, 2011)
  2. Idaho Museum of Natural History – Red-winged blackbird (February, 2011)
  3. Schulenberg, T.S. (2010) Red-winged blackbird (Agelaius phoeniceus). In: Schulenberg, T.S. (Ed.) Neotropical Birds Online. Cornell Lab of Ornithology, Ithaca. Available at:
  4. Yasukawa, K. and Searcy, W.A. (1995) Red-winged blackbird (Agelaius phoeniceus). In: Poole, A. (Ed.) The Birds of North America Online. Cornell Lab of Ornithology, Ithaca. Available at:
  5. Cornell Lab of Ornithology: All About Birds – Red-winged blackbird (February, 2011)
  6. South Dakota Birds and Birding – Red-winged blackbird (February, 2011)
  7. Internet Centre for Wildlife Damage Management - Blackbirds (February, 2011)