VARIATION IN IRIS COLOR OF FEMALE BREWER'S BLACKBIRDS

Abstract

The pale irides of the Rusty Blackbird (Euphagus carolinus) have often been cited as a useful feature for distinguishing this species from the female Brewer’s Blackbird (E. cyanocephalus). However, recent scrutiny of the latter species in central California has shown that females regularly show pale irides, often indistinguishable from those of the Rusty Blackbird.