The spectacular display of the male Red-winged Blackbird is among the first bursts of color and sound to brighten the spring landscape in the northeastern United States. Brilliant red and yellow epaulettes flash as they fly through fields, pastures, and their favored habitat, wetlands. Males begin these flamboyant displays weeks before female Red-wings return from southern wintering grounds. This display by the male in the foreground is directed at the male in the background: a strong signal of territorial ownership. Resources at stake include food, tall ground cover in which to nest, and water for drinking and bathing. The quality of habitat held has as much or more to do with the health of the offspring as do the genes of the parents. This helps explain why males use so much energy to maintain prime territory. Females are as interested in the terrain a male holds as they are in what he looks and sounds like. A male successfully defending a good spot may mate with up to 15 females in a season. Female Red-wings appear very different from males and are easily mistaken for another species, blending beautifully into the territory that they’ve selected. They forage constantly as the breeding season progresses. These are capable and versatile predators, combing the habitat for small arthropods and other minute animal prey, high-protein food to support egg production and growing young. Nests are well-hidden, keeping vulnerable chicks concealed until fledging. Chicks remain dependent on the parents for up to five weeks after leaving the nest. When not on territories, these highly social animals forage and roost in large flocks. Males hide their dazzling epaulettes when in groups, so as not to provoke their flock mates, but throughout the breeding season Red-winged Blackbirds display in full glory, a loud, colorful announcement to keep off their turf.End of transcript
Red-winged Blackbird males secure breeding territories in the early spring before females return from their southern wintering grounds. Males spend much of their time during the breeding season patrolling territorial boundaries and fending off intruders by performing wing-spread displays that highlight bright red shoulder patches. When the females return, they choose their mate partly on the quality of his territory, making sure that it has an abundant food supply of small arthropods, water for drinking and bathing, and tall grass for safe nesting sites. Because the top males can defend territories that safely support multiple nests, you will often find multiple females nesting within high-ranking male territories, making Red-winged Blackbirds one of the most recognizable examples of resource-defense polygyny in birds.