A young Red-winged Blackbird (Agelaius phoeniceus) perches amongst common cattails (Typha latifolia) at Great Meadows National Wildlife Refuge.
The red-winged blackbird is found throughout most of North and much of Central America. It breeds from Alaska and Newfoundland south to Florida, the Gulf of Mexico, Mexico, and Guatemala, with isolated populations in western El Salvador, northwestern Honduras, and northwestern Costa Rica. It may winter as far north as Pennsylvania and British Columbia, but northern populations are generally migratory, moving south to Mexico and the southern United States.
The red-winged blackbird has been considered the most abundant living land bird in North America, with more than a million birds per flock and the total number of breeding pairs across North and Central America exceeding 250 million in peak years. The red-winged blackbird is sexually dimorphic with the male being all black with a red shoulder and yellow wing bar, while the female is a nondescript dark brown. Red-winged blackbirds are polygynous, with territorial males defending up to 10 females. Seeds and insects make up the bulk of the red-winged blackbird's diet.
Male red-wing blackbirds are 22–24 cm (8.7–9.4 in) long and weigh 64 g (2.3 oz). Females are smaller. The build their nests in cattails, rushes, grasses, sedge, or in alder or willow bushes. The nest is constructed entirely by the female over the course of three to six days. A clutch consists of three or four, rarely five, eggs. Eggs are oval, smooth and slightly glossy, and measure 24.8 mm × 17.55 mm (0.976 in × 0.691 in). They are incubated by the female alone, and hatch in 11 to 12 days both blind and naked. However, they are ready to leave the nest 11 to 14 days after hatching.