Vancouver Avian Research Centre

.....Research - Conservation - Education
Species: Red-winged Blackbird Agelaius phoeniceus

Description:

The Red-winged Blackbird is perhaps the most abundant and most commonly studied bird of North America. Although this Blackbird varies in size geographically, adults of all populations are sexually dimorphic in size, plumage, and behaviour. The male is larger, possesses the more conspicuous definitive adult plumage, and is more conspicuous in his behaviour than is the female.
The Red-winged Blackbird breeds in marsh and upland habitats from southern Alaska and central Canada to Costa Rica, and from California to the Atlantic Coast and West Indies. This blackbird migrates to and from the northern portions of its breeding range, but some populations in the western United States and Gulf Coast are known to be resident year-round, as are populations in Middle America.

Identification:

General: Medium sized, sexually dimorphic blackbird with medium-length, slender bill.
Length 22 cm, weight 52g.

Adult Male: Male displays delayed plumage maturation; third-year and older male is glossy black with “epaulets” of red (for which species is named) bordered with yellow on wrist (bend) of wing. Second-year male is highly variable in plumage, from female-like brown with heavily streaked breast to black with brown flecks; epaulets are also variable, typically red-orange with brown or black spotting.

Adult female: Females also show some delayed plumage maturation, but less than male. All females are mottled brown above and heavily streaked below with a prominent white eyebrow stripe. Third-year and older females are variable in throat (pink to buffy) and epaulet (dull orange to bright red-orange) colour. Second-year females are less variable, throat and face light pink, epaulets brown to salmon.

Juvenile: Similar to adult female, but darker and with an orangish shoulder patch bordered by white.

Similar Species: Red-winged Blackbird is unmistakable over most of it range, but from southern Oregon to northern Baja California overlaps in range with very similar Tricoloured Blackbird ; male Tricoloured has red epaulets bordered by white, not yellow, lesser-coverts. Female Tricoloured is very dark, with diffuse streaking, but not always safely distinguished from females of some races of Red-winged Blackbird.

Behavior: Known especially for feeding by gaping, i.e. forcibly opening bill against resistance. Uses gaping to expose insects hiding in the sheathing of leaf bases of aquatic plants, under sticks, seeds, or other objects on the ground or on floating vegetation, and under stones in stream riffles. Also captures food simply by picking up seeds and other items from ground and buy gleaning insects from vegetation.
Red-wings form the nucleus of huge flocks of mixed blackbird species that feed in fields, pastures, and marshes from early fall to spring.

Habitat: Breeds in a variety of wetland and upland habitats. Wetland habitats include freshwater marsh, saltwater marsh, sloughs or where bushes and small trees grow in and around ponds, lakes, sluggish streams. Upland breeding habitats commonly include sedge meadows, alfalfa fields and other crop lands, and old fields; less commonly in wooded areas along waterways and in open patches in woodlands.

Information:

The Red-winged Blackbird is known for its polygynous social system. Up to 15 females have been observed nesting on the territory of a single male, making this one of the most highly polygynous of all bird species. Recent molecular studies have shown that territory owners do not necessarily sire all of the nestlings on their territories, which demonstrates that females as well as males often copulate with more than one partner during a breeding season and even for a single nesting attempt.
The nest is situated in cattails, rushes, bushes, trees sometimes over water, in alfalfa and other plants of upland fields, even on the ground in dense grass.
It is a loosely woven cup of dried cattail leaves, sedges, fastened to plants or twigs with plant fibers, cup lined with fine grasses, rushes. 3-5 pale blue-green, heavily marked eggs.

Conservation Status: No concerns.
 
Capture Rates


Some populations of Red-winged Blackbirds are year round residents of the Lower Mainland while other populations move short distances south for the winter. Capture rates of this species (2010-2012; standardized as birds captured per 100 net hours) occur in almost every month of the year in good numbers. However, numbers especially peak in February due to the influx of non-resident birds returning to their breeding grounds.

 

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