Enlarged photo of Yellow-billed Cuckoo
I further cropped one of the photos below to super enlarge the face of this Yellow-billed Cuckoo to show it's grayish orbital ring. I haven't often either viewed a Yellow-billed Cuckoo up close or taken photos that provide the close-up views as I did with the bird I found yesterday in Van's Grove. I have seen in Sibley's and National Geographic (6th ed) that they have a yellow orbital ring and show drawings of both adult and juvenile birds with yellow orbital rings. When I cropped my photos to enlarge them it was clear that the bird I found did not have a yellow orbital ring-it was grayish. So I did some reading and now am confused. Birds of North America online states, "Orbital skin pale yellow in nestling; grayish in adult." McGill Bird Observatory (has banding photos) states, "A quick and reliable way to determine age in Yellow-billed Cuckoos is by the orbital ring, which is yellow in HY/SY birds (until late winter or spring) and grayish in o...