Blue-winged Warbler / fall composite
There is little difference between the spring and fall plumages of the adults of this species. It can be difficult to age and sex this species and it can be safely done in fall only at the extremes of plumage. The dullest plumage is the first fall female and the individual at the bottom is a good representative of that. Notice the olive and yellow and how low contrasty the bird is. There is some slight contrast between the extreme forehead near the beak along with the area just above the eye compared to the more olive crown and back. There is no bright yellow anywhere. The eye line is not as black and the wing bars are much thinner. The beak of all fall birds of this species is lighter in the fall but the first fall female beak is a pinkish brown.
The bird on top is probably a fall adult male. There is lots of contrast between the olive and yellow areas including the forecrown area. The wing bars are thicker and the eye line is unquestionably black. First fall males and adult females are intermediate in plumage between these two and some of those may at their extremes closely resemble the bird on top.
Blue-winged Warbler / fall composite
There is little difference between the spring and fall plumages of the adults of this species. It can be difficult to age and sex this species and it can be safely done in fall only at the extremes of plumage. The dullest plumage is the first fall female and the individual at the bottom is a good representative of that. Notice the olive and yellow and how low contrasty the bird is. There is some slight contrast between the extreme forehead near the beak along with the area just above the eye compared to the more olive crown and back. There is no bright yellow anywhere. The eye line is not as black and the wing bars are much thinner. The beak of all fall birds of this species is lighter in the fall but the first fall female beak is a pinkish brown.
The bird on top is probably a fall adult male. There is lots of contrast between the olive and yellow areas including the forecrown area. The wing bars are thicker and the eye line is unquestionably black. First fall males and adult females are intermediate in plumage between these two and some of those may at their extremes closely resemble the bird on top.