Suspected hybrid Great Black-backed x Herring Gull at Scarfe Ave, Brantford

[Bill Lamond]

Hi,

Today (18 January) Sarah Lamond found a suspected Great Black-backed (GBBG) x Herring Gull (HERG) hybrid at Scarfe Ave on the Grand River in Brantford. I say suspected as you really cannot prove it. However, the bird seemed intermediate in many respects. I went to look at the bird afterwards. It was a neat-looking bird. Initially I thought it looked too pale to be this hybrid as it was paler than a typical Lesser Black-backed Gull adult. But in looking at it in different angles, the colour could be intermediate between a GBBG and a HERG. What struck me instantly on seeing the bird was how thick the bill was and the steepness of the angle at the gonys. The red spot on the tip of the bill was large and conspicuous and there was an obvious black mark within the red that matched the adjacent adult GBBGs. This black mark might be difficult to see in the photos. The bird was larger than a typical HERG and not as large as the surrounding GBBG but size does vary in these species. I think it is unlikely to be a hybrid Glaucous x GBBG as the wing-tip pattern seems totally unlike that of a Glaucous Gull. Also of note was the apparent white eye-arcs on this bird, something I have not noticed on Herring Gulls. However, I noticed on the adult GBBGs that they had this feature but it was not obvious as their heads were typically very white, so very little contrast. I did not notice this feature on the few adult HERG that I looked at there.

By the way no Glaucous-winged Gull when we were there today (3:00-4:00). Nonetheless there were 400+ gulls there today and I think it likely that the GWGU is still flying daily between Hamilton Harbour and the Brantford landfill.

The attached photos above are mine and Sarah's photos are below.

Bill

 

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