Differences in song and sexual dimorphism between Cuban and North American red-winged blackbirds Agelaius phoeniceus
Whittingham, L.A.; Kirkconnell, A.; Ratcliffe, L.M.
Auk 109.4: 928-933
In this paper we show that Cuban Red-winged Blackbirds exhibit relatively less sexual dimorphism in song, plumage and body size than North American Red-winged Blackbirds. We propose a hypothesis to account for these differences and suggest a possible test.