Thursday, 24 December 2020

White Lies

A short, afternoon gull fix at West Bex today. It was cold and sunny, with a brisk NW wind, and there were gulls all over the place. Loads of Common Gulls and a good number of Meds, plus a reasonable helping of everything else. The largest group of Med Gulls was about 40, but many others were scattered about. They were on (and over) the sea, as well as the mere and one or two inland fields. I found one colour-ringed bird on the beach...

I only got this one photo before they all flew, but had read the ring already. White 35ET is from a Belgian project. Details awaited.

At least three Red-throated Divers lurked offshore, but the main attraction by far was the constant to-ing and fro-ing of gulls. However, nothing unusual caught my eye. Walking slowly back towards the car park I noticed a very pale gull flying across the beach towards the mere. Larger than a Med Gull, even before I raised my bins I knew what it was. It was a Herring Gull.

A Herring Gull, Jim, but not as we know it...

Leucistic Herring Gull, with regular 1st-winter and adult.

This bird has been around for at least four days now, and despite appearances it is not pure white. It has been well photographed in flight by Mike Morse. His photos reveal pale, buffish markings on the primary coverts and elsewhere. I was definitely looking at the same bird...

Note buffish markings/wash on primary coverts and underwing

 

Herring Gulls that exhibit leucism to this extent are very scarce. Certainly I can only recall seeing one other like it. So I was intrigued to know whether this was the same bird that Tim Farr discovered at Sutton Bingham Reservoir back in October, and which featured in this post. It had a similarly scraggy look, but then white feathers do have a tendency to wear rapidly. It also had a similar 'expression' to my eye. I know that sounds a bit daft. I mean, how can gulls have an expression? Good question, just humour me. Anyway, the bill pattern looked familiar as well, but the only way to be sure was to compare photos...

Tim's bird bottom left and top right.
 

Size-wise, both are similarly small for a Herring Gull. But note the three obvious dark scapular markings on Tim's bird (arrowed in bottom left pic) - they are absent on the Bex bird. Have they been moulted? Or is it a different bird? The Bex individual also has a slightly cleaner bill base. Is that just what happenes with ten weeks-worth of development? Or is it a different bird? Unfortunately Tim didn't get a photo of the open wing, so I don't know if it had markings like the Bex bird. But...

Buff primary coverts visible below secondaries (arrow) on the Sutton Bingham bird.

So, are they one and the same? I don't know. Probably, is my verdict. You decide.

I love little puzzlers like this, and always like an interesting gull, but am less thrilled at the prospect of this bird getting strung left, right and centre as an Iceland Gull. Seen poorly, or at long range, it's a cock-up waiting to happen.

Still a smart and striking bird though, even if it is a bit deceitful...

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