Heuglin's Gull in Tokyo Bay? (Japan) (1 Viewer)

[Dr. Wolverine the Birder]

Hello! A couple weeks ago, I visited Funabashi Sanbanze Seaside Park, a known location for shorebirds and gulls. This spot has had various rare gulls pop up in the past, and on the day I visited, a wide range of gull sp were present. There were the usual Vega, Slaty Backed, Black Headed, and Black Tailed Gulls on the breakwater, with a couple uncommon species including Kamchatka, Glaucous, Mongolian(Most likely however not confirmed), and Taimyr (whether you consider this a species or hybrid). Amongst the flock, I noticed one individual the same size as a Vega, with a darker mantle, bright yellow legs, and a unique bill pattern similar to Vega, but having a little black mixed in the red. This was only on the lower bill, so it is not a Black tailed. The yellow legs were extremely bright, unlike the faint pinkish yellow of Taimyr gulls. Body structure was also different, having a slimmer appearance. In flight, its wings were extremely dark, recalling a Slaty Backed. Very small apical spots on P5-8. On P10, there is a single small window.

Heuglin's Gulls are rarities in Japan, and many records are unconfirmed due to confusion with Taimyr Gulls. I have not heard of any records of Heuglin's in Tokyo Bay, and so I was doubtful about this individual. I have photographs of this individual, including flight shots. Note that when I submitted this on eBird, the local reviewers have confirmed it. Still, I just wanted to make sure about this sighting.