Friday, 22 January 2010
Caspian Gulls, from top: at least two first-winters (upper three images), a second-winter and a fourth-winter, all at Rainham today.
It was good weather for ducks, as they say, but it proved even better for gulls. Irritated that a morning appointment meant I couldn't get to Rainham until early afternoon, I was positively gutted when I did finally pitch up at a rain-lashed Aveley Bay to discover that not only had the overnighting Tundra Bean Geese long since departed, but also I'd missed an adult Iceland Gull by 10 minutes.
I dashed round to the stone barges and scanned the river with Jono Lethbridge and Russ Sherriff, who had seen the bird drifting upstream on the rising tide towards Coldharbour Point. Our reasoning that it should continue to drift within sight of the barges was sound enough, but a single adult Yellow-legged Gull proved to be the best larid, while many dozens of Black-tailed Godwits on the far shore were the only other species of note.
I then briefly checked Wennington Marshes, where there were two more Yellow-legged Gulls but no obvious white-wingers among the hordes, so reckoned the Iceland was most likely on the tip. This bid for another Rainham year-tick was also unsuccessful, but I quickly forgot about patchlisting as a striking first-winter Caspian Gull caught my eye. It stuck around long enough for the camera, and once it had flown I soon managed to locate another.
Thereafter, the rest of the session was an unprecedented Caspianfest. I had at least two first-winters, very similar in plumage but one with a metal ring on its left leg, and possibly a darker-looking third bird. These were then followed by a second-winter, and finally a fourth-winter type; four different individuals appear in photographs here. It was enlightening to be able to watch them for long periods at a reasonable distance, and to be able to obtain a useful series of images. This is my favourite large gull, at the same time elegant and imposing, even aggressive, and all these birds held their own in a throng dominated by argentatus Herrings and a hefty contingent of Great Black-backs. When time permits, I'll upload more images to my Flickr site.
Another adult Yellow-legged Gull was also present among the masses, and for a moment I thought I had one of the two recent juvenile Glaucous Gulls flying overhead. On closer inspection, however, the large and rather biscuit-toned larid proved to have some dark brown in the outer primaries, and was obviously not a pure 'Glauc' but (presumably) a Glaucous x Herring hyrbid. A graellsii Lesser Black-backed Gull with a red colour ring bearing a white code was, I imagine, from the Orfordness colony in Suffolk (I've seen these birds on the Thames in London before), and when examining the images back home I also noticed a colour-ringed Herring Gull I hadn't seen in the field. But it was the Caspians that were the unequivocal highlight.