The red-winged blackbird occupies open grassy areas, prefers wetlands, and inhabits both freshwater and saltwater marshes, particularly if cattail is present. They can also found in dry upland areas, where it inhabits meadows, prairies, and old fields.
Males spend most of their days defending their territories during the breeding season. He will chase other males out of the territory and anything he deems a nest predator, sometimes going after much larger animals, including horses and people.
Red-winged blackbirds are a highly polygynous species, with most males having at least a few females living within their territory. Although after testing DNA, 25% – 50% of nestlings turn out to have been sired by someone other than the territorial male.
The Algonquian Indians from my area derived the bird’s name from their word for “spotted” or “marked”, memiskondinimaanganeshiinh, literally meaning “a bird with a very red damn-little shoulder-blade”.
I saw these red-winged blackbirds protecting their territory from two Sandhill Cranes (Grus Canadensis) that were just passing through.