[Maine-birds] MEW GULL at Owls Head harbor, and it's American!

I have just seen the photos sent by Don Reimer of the bird seen today and tentatively identified yesterday by Scott Hall (http://ebird.org/ebird/view/checklist?subID=S26951382). It is a 1st winter MEW GULL and appears to be the American race brachyrhynchus (aka Short-billed Mew Gull). It is not, as would be expected, the European Mew Gull of the nominate race canus (and associated taxa). This is the race breeds in northwestern North American and winters along the Pacific Coast but is rarely documented east of the Great Lakes.

Here's the good news. As it turns out, the bird has been there since January 7th! Margaret Viens photographed the very same bird then but was uncertain about the bird's identity. The recent news of a possible Mew Gull got her to look back. I have now seen her photos, and they show the same bird reported by Scott and by Don. I should also say that Don mentioned he had seen a small, unidentified gull at Owls Head recently. Bottom line, this Mew Gull has been visiting the lobster pound pens at Owls Head Harbor for at least 12 days now.

While there are many more records of European Mew Gulls in the Northeast and the Atlantic Coast, one of the most recent records to Maine was also thought to be an American bird. (There are two other intervening reports of Mew Gull, but the race and identification of those has not been established with certainty.) Some might remember that Don Reimer found this other Mew Gull. It was at Thomaston in August 2013. Here is my analysis of that bird detailing why it was likely a North American bird: https://flic.kr/p/fybBe6 (this deals with how to identify an adult brachyrhynchus, however).

So, look for a delicately built, grayish-brown gull that might recall a small Ring-billed or tiny 1st-year Herring Gull. It has a small bill that is greenish-gray basally with a dark tip, a relatively big and dark eye, a pale gray panel across the upperwing, a solidly dark brown tail (no tail band), and a rump that is heavily mottled with large brownish bars. From below, the underparts are completely washed with grayish-brown and the underwing is a rather uniform silvery gray-brown with no dark bar showing through along the secondaries (the Eurasian taxa of Mew Gull from Europe to Kamchatka show a stronger dark bar from below, and Ring-billed show this strongly in 1st winter). The undertail coverts are heavily marked gray-brown like the rump and upper tail coverts.

All in all, a really super rarity.

Louis Bevier

Fairfield