A morning at Rainham

One of the great things about evening news shifts is that I have hours of daylight to play with in the mornings. Although it doesn't matter so much in the summer months, it is pretty crucial to me getting out birding during the winter. Anyway, I decided to spend the morning at Rainham Tip, a site I visited properly for the first time last month (after dipping the Slaty-backed Gull early in 2011). It turned out to be a productive visit, with three Caspian Gulls, 50+ Yellow-legged Gulls and a couple of medium-dark-mantled gulls, one of which very similar to these purported 'atlantis-types' that have turned up in the Midlands. I'll do a blog post on the latter, later.

I'll start with the cachinnans, of which all three were seen on the tip itself. First up was a green-ringed bird that had dropped its longest primaries, making it seem slightly more dumpy than it really was. I must admit that I can get a little perplexed when trying to age 'older' Caspian Gulls at this time of year when views aren't great, and this latest individual also confused me - particularly as it was never seen in flight. I guess this bird is a 4cy bird (going in to fourth-winter), with the greenish wash to the bill and black subterminal markings rather extensive. Sadly, it never came close enough to read the ring.

The second bird, a first-summer, appeared for all of a few seconds. I managed a record shot of it facing away, but it soon dropped out of view never to be seen again. Not the prettiest bird, it had dropped all its primaries but hadn't really moulted any scaps. Robust individual, though.

The third, appearing in time for Rich B's hour-long visit late morning, really was a fine beast - a great advert for how obvious adult Caspian Gulls can be. It was massive; both long-billed and rangey as it towered over most of the other gulls present. In active primary moult, with p7 regrowing, p8 dropped and p9+10 retained. P10 on the bird's left wing had snapped off. It spent much of its time displaying, throwing its head around and calling with wings held open. Note the yellowish legs.

And then, of course, there was the usual rabble of Yellow-legged Gulls. There are a lot of 1cy birds around at the moment; most are already well underway in their moult to first-winter plumage, although there are still the occasional younger-looking individuals. Also had around ten 2cy birds today - notable in the absence during my July visit. All others were adults/near-adults:

Ringed juvenile Yellow-legged Gull

In my previous posting on Sunday, I remained intentionally vague about a yellow-ringed juvenile gull seen at Rainham on Saturday. In the field, Rich and I had no qualms about identifying it as a Yellow-legged Gull, although when initial research suggested the colour and code ('H8J0') was typical of a scheme on Heligoland, Germany, we began to worry. Surely if this was a Herring, it would be right back to the drawing board for juvenile gull identification?!

German-ringed Yellow-legged Gull 'H8J0'

Close-up of the darvic; use your imagination!

Thankfully, the idea that this bird was Herring (or even Lesser Black-backed) turned out to be as far-fetched as it seemed in the field on Sunday - this bird was pulli ringed as a michahellis in a colony in central Frankfurt on May 18th. Relief all round, and no need to throw any of our present understanding (and literature) in the bin! Here's the beef:

Thanks to Rich for getting on with the detective work; unfortunately my blog looks a bit of a clone of his at present, although he is off on holiday for a few weeks and thus I might actually have something to post that he doesn't.

Summer gulling...

... had me a blast.

Great morning down at Coldharbour Lane, Rainham yesterday morning (21st). Rich B and I had originally intended to spend the morning at Cross Ness but, on waking up and hearing news that that bloody torch was in Greenwich, we diverted north of the Thames and headed east for Rainham. What a good decision that turned out to be.

Having grown up gulling in Peterborough, I'm used to larids being challenging to see and, when you finally get in a good position to look at them, you face the probability of flushing the lot as they're inevitably both wary and flighty. As I've said before, you rarely get a good view of the majority of gulls present in a session; most of the sites they frequent are private, difficult to get in to, or both. I would say that in an average session I manage to check less than 50% of the gulls, with this total particularly low in summer when vegetation hampers viewing even further.

So, what of such a rant? Well, I must say I was hugely impressed with the setup at Rainham. Having the pleasure of being able to see hundreds of gulls unobscured and at relatively close range is always great for me, but particularly so in summer. Here you get great views of the birds loafing on the Thames by the stone barges, and also good views loafing within the tip complex itself. Unsurprisingly, I was keen to get stuck in, pulling out this 2nd-summer Caspian Gull almost right away:

3cy cachinnans: note the small white mirror on retained p10 - diagnostic of the species

... and here you can see the retained third generation tail feathers.

It quickly became apparent that there were shed loads of Yellow-legged Gulls around: in the three or so hours we spent at Rainham, we estimated that we had seen at least 40. Many of these were juveniles; some were really blatant but others had us scrutinizing much more closely - experience from foreign trips to e.g. Morocco has taught us both that michahellis can be remarkably Lesser Black-backed-like, and vice versa. The rest of the birds we saw were 3cy+, with plenty of second-summers and adults although strangely, we could not find a single first-summer anywhere. This is something I've noticed in Peterborough; 2cy birds are often present throughout June and early July but slowly decrease in number, being replaced by juveniles and older birds as July progresses. Not sure why this is, but it can't all be down to inept observers!

Juveniles of argenteus (left) and michahellis (right).

Juvenile michahellis having a stretch, juvenile argenteus looking dumb.

4cy michahellis: particularly washed out bare parts on this one.

Juvenile michahellis having a drink on the Thames.

Another juv michahellis; note commenced moult in the scaps.

Pseudo-michahellis, presumably intermedius?

Rich picked out a smashing juvenile Mediterranean Gull (probably the freshest I've ever seen) while, earlier in the morning, I cottoned on to harsh 'kir-iick' of an adult Sandwich Tern as it bombed westwards upriver - had there been a breath of wind, I imagine it would have sneaked by unnoticed. We also had a few locally-ringed Herring Gulls, and a juvenile gull complete with yellow ring. Hopefully report back on this later in the week, as we're a little confused right now.

Leaving the sights and smells of Rainham behind, we headed over the Thames (via a snarled up Dartford Crossing) to Crayford. Very few gulls here, so we continued west to Cross Ness. Again, it was very quiet along the foreshore on the rising tide, with entertainment being provided by four Black-tailed Godwits and at least six Common Sandpipers. After scoring a McDonald's, it was back towards birdless West London for a sleepy afternoon in the sun.