Red-winged Blackbirds are common throughout the continental U.S. I have seen hundreds of them in late summer at Cesar Chavez park in Berkeley, Ca. Their harsh vocalization is very recognizable. One fact I read said that the male is polygamous and can nest with many females. A lot of males must be nest-less, because I seem to see more males than females in my walks.

The Red-winged Blackbird is omnivorous. While it primarily eats plant materials, including seeds and fruit, it also eats insects, snails, frogs, eggs, carrion, worms, spiders, mollusks.