A white-winged Herring Gull

20 March 2007 | Marek Walford

On 4th February 2007 Fraser Cottington found a "white-winged gull" on Black Swan Lake at Dinton Pastures. Brian Bennett and I got there a few minutes before the bird flew off west, presumably to roost at Sonning Eye GP (Oxon). I managed to get a few very poor quality photos before the bird flew off. Chris Heard made the following comments on the Yahoo Group.

'Thayeri-type' Herring Gulls do not acquire the extensive white on the wing-tips (and reduced black) as a result of wear/bleaching - they are believed to be a northern variant of L.a.argentatus that also tends to be a bit smaller. There are still a number of them around at the moment (although many Northern Herrings have already moved off).

There is another possibility:

Argenteus Herring Gull - last Wednesday (31st), at Burghfield GPs, I observed an adult argenteus that was still regrowing the primaries (very delayed!) and consequently the visible pp tips were mostly white/ish (but one wing appeared slightly shorter than the other... is this the case in one of your shots: photo # 2 - the full profile?).

A few days later I received an email from Dave Harris who had seen and photographed a "white-winged gull" in the roost at Island Barn Reservoir (Surrey) on 7th February. It was seen the same day at Beddington SF and again on the 9th.

Island Barn gull

"White-winged" Herring Gull : Island Barn Res. (Photo: Dave Harris)

Island Barn gull

"White-winged" Herring Gull : Island Barn Res. (Photo: Dave Harris)

Island Barn gull

"White-winged" Herring Gull : Island Barn Res. (Photo: Dave Harris)

Island Barn gull

"White-winged" Herring Gull : Island Barn Res. (Photo: Dave Harris)