Euphagus

Euphagus is a small genus of New World blackbirds. It contains two North American species, the Brewer's Blackbird, Euphagus cyanocephalus, and the Rusty Blackbird E. carolinus. Both species are migratory, wintering in the southern United States and Mexico, although some Brewer's Blackbirds are present all year in the western USA.

A prehistoric relative, Euphagus magnirostris, is known from Late Pleistocene fossils found in the famous tar seeps of Rancho La Brea, California.

The living species are very similar medium-sized birds. Adult males have mainly black plumage and a bright yellow eye; the females are dark grey-brown.

They build cup nests, and the female alone incubates the eggs. They are gregarious outside the breeding season.

Both species feed on seeds and insects, the Rusty having a particularly high insect component to its diet. The fortunes of the two species are contrasting, with Brewer’s expanding east in the Great Lakes region, whilst Rusty shows a worrying decline in numbers.