Lesser Black-backed Gulls on Grand River, Brantford

[Bill Lamond]

Hi,

Here is a familiar headline. Today (5 September) I visited the Grand River at Scarfe Ave in Brantford, a hotspot for loafing gulls. Naked-eye I could see that the 200+ gulls on the gravel bar was almost entirely Ring-billed Gulls. I scanned them with the scope and it was 100% RBGU. I looked upriver and could see one dark juvenile Herring Gull with some other RBGU. I continued to scan upriver to look for ducks, herons, swifts/swallows and shorebirds. It was time for supper so I was anxious to go but I thought I would examine the gulls again in case I overlooked a Mew Gull or something of that ilk. I was surprised to see a Lesser Black-backed Gull, and then another, then another, then another... I counted 19 LBBG all closely grouped together amongst the RBGU. Where did they come from?! They must have flown in as a flock when I was looking upriver. Very odd. There was one juvenile, one 1^st summer, two adults and the rest were adult-like, mostly 3^rd summers with perhaps a couple of 2^nd summers thrown in. It was bizarre that this many had shown up all at once. It was also highly unusual that most of the birds were sub-adults (3^rd summers) as this is usually the least common age class in gulls but here they were dominant. This I cannot explain but then there are lots of things about LBBG that are hard to explain. Their numbers are exploding in eastern North America despite the fact that they do not even nest on this continent. This explosion in numbers is suspected to be the result of this species colonizing Greenland (from Iceland). Breeding was confirmed in Greenland in 1990, and in 2006, 700 nesting pairs were recorded. The population must be much higher than that now to account for all the birds in North America in the fall/winter.

How common will this species become?

Bill