May. Wisconsin. |
Age: The dark tertials and dark wing panel, coupled with adult-like scapulars and dark ear spot suggest a 1st cycle type small gull.
Identification: Given the time of year, this should be a one-year old tern-like gull based on the overall size, white body and dark ear spot. Important here is the white wedge seen on the base of the primaries, just below the tertials. This points directly to Bonaparte's and Black-headed, although the leg color suggests the former. Little Gull might be suspected based on the extraordinarily dark wing coverts (partly due to lighting). That species shows a saw-tooth black-to-white pattern on the folded primaries, with black on the outer webs and white on the inner half. Below is our May Quiz bird, sporting an all-black bill and thin tail band -- a 1st cycle Bonaparte's Gull showing a somewhat darker than average wing panel.