Black-throated Blue Warbler Wing
Detailed Description
Scientists can use clues in the wing to age birds. In this case the bird has molted all its wing feathers recently, so it is an after hatch year male.
Sources/Usage
Public Domain.
Scientists can use clues in the wing to age birds. In this case the bird has molted all its wing feathers recently, so it is an after hatch year male.
Public Domain.