Saturday, February 16, 2008

Gull confusion

I forgot a few further signs of spring from the 13th - Hedgehog poo on the lawn being the main one. I've been told about bats flying and hunting in the last few days as well.

A trip out to the neglected Scaling Dam found me looking at a confusing gull. I thought it was a 1st winter. It was big, with a heavy mostly black bill, pale headed with markings around the eye, it had a broad very black tail band with a white rump that was lightly marked with sparse brown flecks, there was no pale window in the wing and it lacked the distinctive chequered look of a GB-bG. There were GB-bGs nearby and they seemed larger, were distinctly chequered and colder plumaged. My bird was looking good for a Yellow-legged Gull, a 1st W. But hang on, the ends of the tertials are white, that's not right. Ok, so maybe it's one of those delayed 2nd winters, then the tertials can be white at the tip. Danger sign - I'm trying to make the gull fit the id not the id fit the gull.

The bird disappeared whilst I was distracted. At home I consulted Olsen and Larsson and had a look at pix on BirdGuides. I started to feel it could be a delayed 2nd winter Y-lG.

I returned to Scaling for the roost and found the gull quite quickly. It was with an adult GB-bG and was much smaller. I phoned MAB saying I'd got a possible but that I was still bothered by the tertials. Again whilst I was distracted the bird disappeared but this time I relocated it quite quickly. I headed for the hide and watched it dismembering a goose carcass and began to feel very uncomfortable about the possible id, this bird was behaving like a GB-bG. Bored with goose bones the gull swam over to the hide, and revealed itself to be a Great Black-backed Gull. Looking at the pix now I wonder how I thought it could be anything else. In my defence it was small, it lacked the distinctive cold plumage tones and chequered appearance and the tail and the bill led me astray. Bit of a lesson though. Still even Jonsson admits to having bad days, perhaps not that bad a day maybe?

Scaling had a Pochard, 8 Goldeneye, the usual dabbling ducks but in small numbers. I continue to fail to connect with the Water Pipit that has been seen intermittently since just before Xmas.

The Great Cormorants at Scaling are of interest. It might be expected that they are coastal birds drifting inland for a spot of easy fishing but I'm thinking that a proportion of them are sinensis these two candidates above look like prime suspects.

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