Red-winged blackbird (Agelaius phoeniceus) is a common to abundant migrant and resident of wetland habitats of California, except for the highest elevations of the Sierra Nevada. This abundant and widespread bird is not migratory in most of California, but flocks often undergo local movements in the non-breeding season and withdraw from higher elevations in winter. Red-winged blackbird often forms huge winter flocks with other blackbirds, starlings, cowbirds, and grackles.
Red-winged blackbird is a medium-sized perching bird (passerine) approximately 7.5 to 9.5 inches in length. The male is all black, except for a large red shoulder patch edged in yellow or buff. The female has heavily streaked underparts, mottled brown upperparts, a light eyebrow, and a faint red shoulder patch. Both males and females have a thick, pointed, dark bill.
Red-winged blackbird roosts and nests in freshwater and saltwater emergent wetlands containing cattails and tules, or in moist, open habitats with thickets of willows, sedges, or blackberries. This species nests colonially over or near water usually 0.5 to 6 feet above water or ground, in cattails, rushes, sedges, shrubs or low trees. Nesting sites are sometimes located as far as three miles away from water. Red-winged blackbird nests consist of an approximate 4.5 inch diameter cup of long leaves and stems woven tightly around upright supports, and lined with dry grasses, broken plant material, thin rushes, or mud. Breeding and nesting of red-winged blackbird occurs from early March to late July. Usually 3 or 4 eggs are laid and incubated by the female for 10 to 12 days. The young leave the nest at around 10 to 11 days, but do not become independent for another two weeks. This species often raises two sets of young each nesting season.
Red-winged blackbird feeds in wetlands and other moist, open habitats where it gleans food from the ground and from emergent herbaceous vegetation. This species mainly eats seeds and cultivated grains such as rice, oats and corn. In the breeding season, adults and nestlings also eat insects and spiders. Nest predators of red-winged blackbird include raccoons, skunks, minks, grackles, snakes, and other small mammals.
Red-winged blackbirds are common on many WHF preserves, especially those with or adjacent to wetlands.