Fudge Find

I had another good day out close to home today; always the best way, grilling birds along the river and in the parks of southeast London. As it turned out, the best bird seen was at the last site visited - Thamesmere; a small lake by the Morrison's car park in salubrious Thamesmead. John A and I stopped off here on the way home, as we'd had enough of the cold and, away from the main flock of aythyas initially and hiding in the reeds, I found a female Ferruginous Duck. Probably the first for the London borough of Greenwich apparently. It was with 30 Pochard and 15 Tufted Duck, looked wild and didn't seem to show any hybrid characters. Apologies for the shots... my digiscoping camera battery had ran out and it was just a bit too distant for the SLR as these illustrate.

female Ferruginous Duck at Thamesmere

So, what else happened today? I got to Greenland Pier in the hope that Dave Mo's Brent Goose from Battersea would make it downriver to Rotherhithe, but it had other ideas. Had a 1st-winter Yellow-legged Gull on the groynes, and then it was off to check Burgess Park for a bit - no Med Gull again (I haven't seen it since early December) but there was a NTGG-ringed (red/orange ring with black writing) 1st-winter Herring Gull I'd not seen before.

1st-winter Yellow-legged Gull, Rotherhithe

So I sacked it off and headed a short way east to Crossness late morning. John A had already scored heavily with 11 Tundra Bean Geese east early morning, so I met him at Southmere where he quickly found this bird. Initially it looked absolutely bang on for a Casp with a nice slightly dark grey mantle, long parallel-sided bill, long-winged and significant white in the primaries. However this bird shows a relatively large, pale eye and although there's a nice white tip to P10, there's quite a significant amount of dark in the primary shaft. Could this bird possibly be something from the hybrid zone in Poland? Not sure and any useful comments appreciated.

I needed some grub after this perplexing ordeal, so headed off to get a pasty, while in the meantime missed an adult Kittiwake off the golf centre. Serves me right for again not making sandwiches. Anyway, there was a nice selection of bits and pieces, including a load of large g's on the mud - including three with bling. One NTGG group Herring Gull, a Suffolk-ringed Herring Gull and then a Norwegian Great Black-backed Gull.

JN252; ringed at Keila, Hjelmsøy, Måsøy, Finnmark, Norway on 11th June 2008 and this was the first recovery - a straight line distance of 1313 miles

More head scratching as we found another gull on the Thames foreshore. A real beast of a bird, obviously massive and leggy - just look at its size compared to the GBB! I had a 1st-winter Casp on the river a couple of years ago that almost matched this bird in size.

This bird was a near-adult, presumably a 4th winter with some dark smudgings on its primary coverts. Stilt legs, though not too spindly.

Then in flight this bird showed what you want in a Casp, with a nice pale tongue to the underside of P10.

Obviously this bird lacks a bit of maturity, but the wingtips seem pretty developed with an obvious pale outer web to the underside of P10. However, argentatus Herring Gulls can show pretty similar primary patterning to Casps - just compare this wing of an argentatus that I photographed in the hand yesterday.

Extensive pale tip to P10 and lack of any black on P5 put this within the range of argentatus in the ringer's book