Back at the dump

It's approaching that time of year where the days are so short that it rarely seems to get properly light and, to boot, the temperature is abnormally low for so early in the winter season. With a calm day forecast, I decided to seize the opportunity for my first visit to Rainham since the summer, mainly to see what the deal was with tipping activity and where the gull numbers were at.

Gull numbers were fairly low to be honest, though this might be explained by the fact it was a Monday morning. I had 5-10 michahellis of various ages arsing around on the Thames, but no Casps. Bird of the day was a pretty smart 1cy that, to me, can be labelled a Glaucous x Herring Gull:

I'm pretty aware that argentatus can come pretty big and pale - indeed, I see such birds each winter (here's one from Peterborough). However, there's enough to suggest a hybrid in this bird beside its overall paleness:

• large size and overall bulk (compared to Herring)
• tertial pattern
• tail patten: just visible in the bottom photo, a lack of any sort of clear-cut dark band is obvious
• primary pattern: broad pale chevrons as well as arrow-shaped internal patterning typical of Glaucous Gull (e.g. here and here)

Quite a Cach

Second-winter Caspian Gull on the landfill at Rainham this morning - showed a lot better than this rubbish photo suggests. Also 35+ Yellow-legged Gulls this morning.

Rainham on Saturday

This perfect adult Caspian Gull was one of three on the tip at Rainham on Saturday morning - the others being 1cy and 3cy birds. It is quite a bright-billed and dark-mantled individual, and the pale eye can also been seen in the bottom image. My first Waxwing of the winter also dropped in a couple of times as we watched the tip.

1cy Caspian Gull

This first-winter Caspian Gull showed well on the River Thames foreshore late morning until flushed by loud youths on bikes. A further two birds - both adults - were seen on the tip in addition to 15 or so Yellow-legged Gulls.

Note that, in contrast to some messages that have been broadcast, the majority of gulls are NOT at or by the stone barges. I've encountered three independent lost birders on my last two visits to the site. The best place to see gulls is by walking east along the riverside footpath for 300m from Coldharbour Lane. Birds commute between the tip and the River Thames here, and good views can be had of birds either bathing on the river or on the foreshore itself.

Down in the dump

For the first time in a while, I managed to spend the morning at Rainham Tip. Despite a wet forecast, it actually turned out to be an OKish morning weather-wise and, despite the relatively low numbers present, the gulls also produced a few decent bits.

Arriving a little after 08:30, I had a Water Pipit flying around near the stone barges as I made my way along the riverside footpath to the tipping area. This was soon followed by the first Caspian Gull of the morning: a heavy-looking first-winter with really nice scapulars and coverts and a distinct dark smudge behind the eye, which really emphasised the white eyelids.

Over the next few hours, I was joined by a few others including David Bradnum. It wasn't the most dynamic of mornings on the tip with hundreds (rather than thousands) of large gulls, although we did have a further two Casps - a green-ringed second-winter (ring covered in sh*t and thus unreadable) that was a bit retarded on the upperparts and seemed to lack a mirror on p10, and a really smart adult picked up by Dave.

Another Rock/Water Pipit also flew over calling and there were plenty of the expected winter species along the Thames including about a dozen Yellow-legged Gulls (of all ages) throughout the morning. This Rook also showed well on the fence adjacent to where we were stood...

Mid-September Caspian Gulls

Today, I spent about 90 minutes in Butts Hide at Rainham, during which I saw the juvenile Baillon's Crake for about 3 seconds as it ran across a gap in the reeds. Nice bird, but I must admit I felt a huge sense of relief on seeing it. Why? Because it meant I could get back to the landfill site and look at the gulls, of course!

In two 90-minutes sessions today (mid-morning and early afternoon), I had at least five Caspian Gulls, with at least three 1cy birds seen. Interesting to see how worn all three were, being well advanced in their moult towards first-winter plumage.

Bird one was a really bulky-looking beast with a hefty bill. Note that the vast majority of the scapulars have been replaced, and also how worn the coverts are:

Bird two was perhaps the 'best'-looking of the lot, initially picked up flying around over the tip when the pale underwing could be seen with ease. A classic in all respects, this one is less advanced in its scapular moult than bird one, but note structure (long legs, parallel bill, rounded head etc). It looks really similar to this one I had in Peterborough last year.

Bird three was probably the most advanced of the bunch, with a whitish head and almost all scapulars replaced. Although superficially similar to bird one, there are differences in the moulted scapulars, and the bill is both a different shape (more pronounced gonydeal angle) and shows a more obvious pinkish wash to the base. Check out how long and spindly the legs are!

The other two birds were both 2cy, with one much more advanced than the other. Here is one of them, through the heat haze:

Also had this bird. At first, I thought it might be a Caspian Gull, but some features don't really fit - the bold anchors on the newly-moulted scapulars, the shortish legs, the dirty(ish) underwing etc. I guess it is likely a Yellow-legged Gull. Or perhaps even a Lesser Black-backed Gull. Thoughts and comments welcome.

More on Azorean Gulls, I'm afraid

Went back to Rainham yesterday morning. Not as many birds around as on my two previous visits, so could only manage around 25 Yellow-legged Gulls (no Casps). After a few hours of seeing relatively little, I flirted with the idea of heading back home to bed but, on my final scan of the Thames, I spotted the Azorean-type floating aimlessly upriver towards me.

Over the next couple of hours, I only had reasonable views of it on the river and over my head as it flew back towards the tip; it proved frustratingly difficult to locate on the landfill itself, only on view for a minute or two at the most! Here are some shots, including comparisons with both Herring and Lesser Black-backed.

Quite interesting to see how it has changed in appearance. The dark subterminal markings on the bill have intensified in the onset of winter plumage, and the amount head streaking has also increased. The secondaries and tail are in heavy moult; note how the outer tail feathers (that had quite a lot of black left in them back on 21st) have been dropped, leaving a rather messing looking beast. The immature underwing coverts have also been moulted through to white, adult-like feathers since 21st.

It looks pretty decent. Moult timing seems spot on. Primaries look fine. But something just bugs me, and as such I'm still unconvinced. I'd like to see it out of the water for longer and at closer range to get a real feel for structure and jizz though.

To compare moult/plumage, here are a couple of photographs of 'real' Azorean Gulls, taken in the archipelago this week by Rich Bonser. The similarities in moult of the tail and secondaries is striking.

Genuine Azorean Gull influx?

On Sunday, three possible Azorean Gulls were reported in County Cork - at Clonakilty, Rosscarbery and Ballycotton. The first two (a near-adult and a somewhat retarded 3cy) were photographed:

http://www.irishbirding.com/birds/web/Display/sighting/47823/Yellowlegged_Gull.html
http://www.irishbirding.com/birds/web/Display/sighting/47822/Yellowlegged_Gull.html

This adds a fascinating twist to the story of Azorean Gull in Britain and Ireland. Perhaps these streaky-headed, dark-mantled gulls are atlantis after all? Although not worth jumping to any conclusions just yet, it must be noted that we've been subject to a series of trans-atlantic weather systems since the first around 16th August - indeed, the gales that affected much of southwest Britain and Ireland during that first system stemmed right from the Azorean archipelago. Worth thinking about, at least. For good measure, here are a dew more shots of the bird I had at Rainham last Tuesday:

Azorean Gull at Rainham?

During the four hours I spent at Rainham on Tuesday, I had two birds which, for all intents and purposes, may be hybrids. The first bird, an adult, was the less interesting of the two, and was what I would call a likely Lesser Black-backed x Herring Gull, similar to this bird photographed by Dominic Mitchell in late 2011 (could it perhaps even be the same?).

Adult gull, presumed hybrid Lesser Black-backed x Herring.

The second is a 3cy bird, moulting in to a third-winter plumage. Age aside, it looks remarkably like some of these claimed Azorean Gulls of recent autumn/winters (Oxon, Beds) - mantle colouration at the dark end of Yellow-legged Gull, but also too pale for Lesser Black-backed. Structurally, it felt like a Yellow-legged Gull - big and robust, long-winged, with nice and long yellowish legs. Fascinatingly, it had a broad and full black tail band, with some barring left on the uppertail - again, only just visible in the images but nevertheless significantly more than one would expect to see on a michahellis of this age. The retained secondaries (only just visible in the photos) were a dark chocolate brown, and there was also a brownish wash to some of the new lesser/median coverts. A retained tertial (maybe two, I couldn't see) was dark chocolate-brown with some pale scalloping limited to the tip.

I couldn't make out the eyering colour, but reviewing photos it appears to have some reddish tinge to it at least (although atlantis at this age don't necessarily show an obvious red eyering at this age). The iris is a very pale yellow. The head streaking is dense, creating a hooded effect. I was initially put off by how this streaking extends down the nape/neck, although looking at photos shows that this is not a problem in atlantis at this age - had it been an adult, that might have been different.

NB: have been looking at the primary pattern as closely as my (poor) images will allow; the one thing that concerns me is the pattern on p5 - see eighth photo down - although the black band is complete, it does not seem as broad as in the adults that I've seen shots of in flight. However, it looks pretty similar to the Oxfordshire adult of 2009. There also seems to be a hint of black in the outer web of p4. Unfortunately it doesn't help that the bird is in active moult and the primaries just seem to be all over the place. UPDATE: p5 doesn't seem to be out of range.

I've always been pretty sceptical about Azorean Gulls occurring in Britain - at least in the Midlands - and typically opt for the lazy hybrid option. But this bird has fuelled my interests further - this thing looks almost identical to some of the birds I saw on Corvo last October, as well as sharing plenty of similarities this thing photographed on Sao Miguel in September. It's not far off this bird from Terceira, either.

So, what now? Well, apart from muting it as a candidate Azorean Gull, I don't think you can go much further. It would be great to see photos of known hybrids (Herring x LBB or Yellow-legged x LBB), but they seem difficult to come across. All you can say is this bird shares a lot of features with Azorean Gulls of a similar age. However, it would take a braver man than me to totally rule out the possibility of a hybrid of some description.