Wednesday, 26 May 2010

Oh my godwit!

This Black-tailed Godwit at Rainham is strongly suggestive of nominate limosa rather than the expected islandica subspecies. Note the washed-out tone of the chestnut head and breast, the fact that it doesn't extend down over the breast, and the plain upperparts.

I've been out in the field quite a bit since last weekend's post, but with little to show for it. The same applies to this morning's jaunt to Rainham, then Grays, then back to Rainham and finally the Warley area. Of the few minor sightings of interest, which have included more Common Buzzards, Hobbies, Cuckoos and Yellowhammers in suitable breeding areas (but still no Turtle Doves), possibly a wader is of most interest.

Shorebirds have often been conspicuous by their absence at Rainham this spring, especially on the reserve itself, despite plentiful pools and patches of standing water (albeit rather overgrown ones). So finding a late Greenshank on the reserve was nice, as was a Black-tailed Godwit - the first I've seen here for a few weeks. This latter bird also stood out from those typically seen on spring passage in Britain - which are usually richly coloured islandica individuals - with its subdued breeding plumage, the chestnut being washed out in tone and also restricted largely to the head and neck. The upperparts were also relatively plain.

As almost all passage and wintering Black-tailed Godwits in Britain are considered to be islandica, and the British breeding population of nominate limosa is only 50-60 pairs, just how unusual is this sighting (assuming it indeed relates to limosa)? The Birds of Essex (Wood 2007) states: "There is no direct ringing evidence linking Essex with limosa. Indeed, there is no evidence of limosa from continental breeding populations occurring in Britain on passage (Migration Atlas); an Essex specimen, one of many ascribed to limosa in the British Museum of Natural History (Vernon 1963), was presumably from the small British population of this race."

After a quick search the information on nominate limosa occurring in the London Area seems even more vague, if not non-existent. So this sighting is potentially significant - assuming, of course, that it does relate to limosa? The most useful recent reference I can find is Vinicombe 2005 (Birdwatch 154: 18-20), in which it is stated: "... a summer-plumaged islandica in spring may be separated from limosa if it shows all of the following features: (1) a shorter bill and legs (the bill averages about 1 cm shorter); (2) at least 70 per cent of its body feathers are in summer plumage; (3) the orange plumage is deeper and more 'saturated' and rufous in tone; and (4) the rufous on the underparts extends further down onto the flanks and is more extensively barred with black on the belly, flanks and undertail -coverts." On points 2, 3 and 4 the images of the Rainham bird certainly seem to suggest limosa and not islandica; point 1 is perhaps impossible to be sure of in the field, given variation and differences between males and females of both taxa.

And what does first-summer islandica look like? Vinicombe comments that "first-summer Black-tailed Godwits retain greater numbers of non-breeding feathers, breeding plumage being restricted to the head, scapulars, mantle and the sides of the breast". This is clearly a potential pitfall for the Rainham bird, though I've read elsewhere that even first-summer islandicas will likely show some variegated patterning on the upperparts.

I feel on balance that the Rainham bird has good credentials for limosa, but all comments welcome.

Also on the reserve today were this brief Greenshank and two Yellow-legged Gulls (either side of the adult graellsii Lesser Black-backed Gull), neither of which appears to be the bird hanging around Aveley Pools over the last two weeks.

Saturday, 22 May 2010

Question time

"What are you doing?" she said. "I'm photographing Swallows," I replied. "That's private property over there," she warned. "I know it is. That's why I'm standing on a public footpath," I retorted. Why buy a house on a public footpath, and then ask passers-by what they think they're doing? If the idea is to put them off, it doesn't work. I continued my walk around the hamlet of Greensted in an ultimately vain search for Turtle Dove.

I did, however, see the oldest wooden church in the world (or, more accurately, the oldest church made partly from wood, as the spire is clapboard and brick additions mean that the wood is now a minority material). It's very picturesque, and no doubt Turtle Doves and far more exotic fare would have been found in the vicinity when it was built 1,200 years ago. Today, a calling Little Owl, four singing Yellowhammers, at least two Cuckoos and a nice clutch of warblers were the best this site on the very edge of the London Area could offer.

I repaired to nearby Stanford Rivers, also previously a Turtle Dove site. Again no joy, but I picked up a distant soaring Common Buzzard and then a real piece of luck: a female Bullfinch in an overgrown hedgerow. Persistence had paid off, albeit not in the way intended. Sensing I was on a roll I continued south to Orsett Fen (with a Hobby en route) to try and pin down a Common Quail found two days ago; at least four more Common Buzzards here showed how well established this species now is around the edge of London, though there was no trace of the quail.

A raptor-watching session in the afternoon back at Alexandra Park brought the second question-and-answer session of the day. "Afternoon," said the security patrolman. "Hi," said I, looking through my scope. "You're not taking photos, are you?" he said. "Er, no, it's a telescope," I replied. "Good," he said. "But I will take photos if I want to," I added, refusing to be brow-beaten by a jobs-worth who knows that film crews need to get permission to film here. No such approval is needed for scanning for raptors, or photographing them; the latter wasn't possible with the distant fly-by Peregrine yesterday, nor today's Common and Honey Buzzards which sparred briefly before sharing a thermal as they drifted east past Bob Watts, Andrew Gardener and I.

So instead, here's what Greensted church looks like.
And here is my London year-list, duly updated:
180. Bullfinch.
181. Honey Buzzard.

And finally, last weekend's ringed albino Herring Gull at Rainham has been traced - to Rainham! Thanks to Paul Roper for this nonetheless interesting history of the bird.

Thursday, 20 May 2010

Big day out

From top: Woodlarks discovered in potential breeding habitat; and Tree Sparrow and part of the gull gathering at Beddington.

Today it was time to spread my wings. So far this year my birding in London has focused on the north and east - think of the capital's recording area (a 20-mile radius of St Paul's Cathedral) as a clock face, and I have not ventured outside the 11-3 zone. It has done well, but the time had come to strike out.

I was up at 4.30 am and birding at Staines Reservoirs, in the shadow of Heathrow, a couple of hours later. My target was Little Gull, with one having been reported there as recently as last weekend, and eventually I picked up what was surely the same bird (a third-calendar-year) among the most distant group of Black-headed Gulls. Common Terns provided far better photo opportunities, while single Yellow Wagtail and Dunlin were the only other obvious migrants.

After a surprisingly smooth passage around the M25, I picked up Mike Spicer and we headed off into the unknown; well, kind of. Woodlarks have occasionally bred on the fringes of London, so we wanted to know if they could still be found. At a site where the habitat looked slightly less than ideal, and which was heavily disturbed, we eventually hit the jackpot with two birds feeding at close range - bingo! It's good to know that this enigmatic lark is still around the edge of town; how successful any breeding is likely to be at this site is another matter, however.

Next up was Beddington, so we met up with Peter Alfrey outside the 'obs' (as his flat is known) on the edge of this south London hot-spot. A former sewage farm, it has changed dramatically since I was last there, and in place of most of its old sludge beds has a landfill site and lakes teeming with gulls - more than there are at Rainham at this time of year - as well as plenty of its signature bird, Tree Sparrow (one of only two remaining breeding sites in the capital). Little Ringed Plover, Lapwing and Redshank were the only waders today, but a fly-over Common Buzzard was also noteworthy.

I completed the 166-mile, 13.5 hour circular route by returning via Rainham, where for the second time in the last few days a Rainham had put in a brief appearance. I checked the dump early evening, just in case, but to no avail; maybe tomorrow.

London year-list update:
176. Sanderling (four at Rainham on Tuesday 18th May).
177. Little Gull.
178. Woodlark.
179. Tree Sparrow.

PS Thanks to Bob, Rob, Mike, Peter, David, Mark and Howard for information and news today.

Saturday, 15 May 2010

On target

From top: this second-summer Yellow-legged Gull was again on Aveley Pools; an adult Peregrine looks on from its pylon vantage point; the colour-ringed albino Herring Gull; and female Yellow Wagtail at Holyfield.

I had unreasonably high hopes of finding something good this morning, largely because it's 16 years to the day since I discovered a singing male Subalpine Warbler on my old local patch of Walthamstow Marsh in east London. But though mid-May is a good time to be looking for vagrants, repeating the feat on the same date is of course a statistical improbability - even if I was momentarily buoyed by an arrival of passerines the previous day which included my first Spotted Flycatcher of the year at Stoke Newington Reservoirs (thanks to Mark Pearson for that one).

That flycatcher was my 175th species for London in 2010, thereby meaning that by mid-May I have already reached the target I set for the whole year. The likelihood is that I will now reach 185-190 species, potentially almost 20 more than I have logged in a year in London previously, but the 200 mark seems beyond reach.

Notwithstanding the lack of vagrants Rainham was still interesting todayup, with Peregrine, Hobby, a late drake Eurasian Wigeon, Little Ringed Plover, three Common Terns, Cuckoo, Northern Wheatear and adult and second-summer Yellow-legged Gulls. I met up briefly with David Callahan, Mark Pearson and John Archer as their team racked up species on the Oystercatcher Bird Race (they went on to win with a total of 90 species recorded in London boroughs using public transport). Down near the dump we had another second-summer Yellow-legged Gull, a stunning albino Herring Gull, excellent views of Grasshopper Warbler and a fly-over Common Buzzard, before I decamped to the Lee Valley in an abortive attempt to see a Temminck's Stint at Holyfield; instead, another Common Buzzard, seven Hobbies, four Little Ringed Plovers, Yellow Wagtail, Garden Warbler and Yellowhammer were the highlights.

And the hunt for Turtle Dove continues ...

Thursday, 13 May 2010

With these words ...

From top: Tree Pipit in Epping Forest; Great Crested Grebe with its catch of the day; a Hobby shows well at Rainham; and a second-summer Yellow-legged Gull at the same site.




… I thee condemn: “You can’t miss it.” How many times have you heard that, and then failed to see the target bird? It’s like wishing an actor good luck for their big stage performance; the opposite result is immediately bestowed upon them. I should have remembered this when Jono gave me directions to an “unmissable” Little Owl at a site on the Essex fringe of London. As grateful as I was for the directions, I duly failed to nail the owl in its “favoured” tree. After a 4.30 am start in temperatures of just 1.5 degrees C (and ice on the windscreen - in May!), my fourth London Little Owl dip of the year was confirmed.

So I headed off to the Lea Valley, pausing en route in Epping Forest on a whim to check a site where, on our record-breaking London big day in 2006, my team had notched up Tree Pipit. With the sun now well up the car park was a safe prospect, so I ventured out through a patch of oak and beech woodland to some rough birch scrub where, after a short wait, a singing male Tree Pipit duly put on a fine performance.

With my luck picking up, I arrived at Holyfield to check the farms for Turtle Doves. A quick scan produced a dumpy shape in a leafless tree which resolved into … a Little Owl! So there is a god after all. Now firmly on a roll, I found a drake Garganey on Langridge Scrape, a singing Nightingale nearby and nine warbler species, while a quick stop to check King George V Reservoir produced a cracking full summer Turnstone – just as Lol Bodini and I were having a text exchange about the one he found yesterday at Walthamstow. Serendipity, or what? Who knows – it may even have been the same bird.

Rainham felt more predictable by comparison, but it still produced an adult female Marsh Harrier, three Hobbies, four Whimbrel, a Curlew, a second-summer Yellow-legged Gull and four Northern Wheatears, including a nice male Greenland.

Today’s net gain was three London year-ticks (though no patch ticks):
172. Tree Pipit.
173. Little Owl.
174. Turnstone.

Tuesday, 11 May 2010

Bunting impressionist



I had to share this video, taken by David Erterius two days ago in southern Sweden and posted yesterday to WestPalBirds. Corn Buntings aren't known as mimics, though apparently the phenomenon has been recorded before. It's a remarkably decent impression of a Yellowhammer's song, though I suspect that female Yellowhammers won't be fooled (if they were, the resulting hybrid would be an interesting specimen).

And while we're comparing birds, Jono Lethbridge has pointed out that the female Northern Wheatear in the image from Rainham that I posted yesterday is remarkably similar to the bird he photographed there on 29 April - compare the damage to the tip of the lower mandible on his bird (http://tinyurl.com/32z62po) to mine. That means it has been present for 12 days, a long time for a spring migrant - perhaps it is being held up by feeding difficulties, or maybe it might stay to breed? Northern Wheatears do not nest locally, though I did once find a July juvenile which I am sure was probably locally reared.

Monday, 10 May 2010

Early doors

Upper two images: Grasshopper Warbler at Rainham and a female Northern Wheatear (perhaps leucorhoa) with damaged bill.

Dawn hadn't broken by the time I arrived at Rainham this morning, but the early start was essential. I was looking for Grasshopper Warbler in a quiet corner of the marsh, and the earlier the better for this songster - except that today it wasn't singing. I knew I was in the right area for a territory and persisted, and eventually found not one but two birds - the male just occasionally emitting a few seconds of reeling. Perhaps the fact that he's already paired up, and there are no rival males nearby, means he doesn't need to sing any more.

Mission accomplished, I headed for Aveley Bay to look for waders, but a single Redshank was a paltry showing after yesterday. There were terns on the river, however, and among 20+ Commons was at least one Arctic moving downstream. I checked the mud in the bay again and four Grey Plover, three of them in immaculate breeding dress, had appeared from nowhere. They went back there too after being disturbed by a Carrion Crow, but apparently they reappeared in the bay later on. Also at Rainham were four each of Whimbrel and Oystercatcher, three Ringed Plover, Dunlin, Greenshank and eight Northern Wheatears - but still no Whinchat for the year.

By late morning I was on the road to the Lea Valley, but failed to connect with the Turtle Dove(s) reported at Holyfield earlier today and yesterday. I did connect with Jono, though - he had heard one 'purring' but not seen it. A scour of Hayes Hill and Holyfield Farms failed to produce any notable doves, but from the hill-top viewpoint a Wood Sandpiper, Greenshank and two Little Ringed Plovers on Langridge Scrape and four Hobbies, Cuckoo, Garden and Willow Warblers, Lesser Whitethroat and Yellowhammer all made the diversion worthwhile.

I detoured further still en route home to Tyttenhanger but missed the Black Redstart there. Amazingly, Bob Watts found one this evening in Alexandra Park, on my doorstep, so I managed to see one today after all (plus another Hobby there). A long day ended in company with four other birders in Regent's Park, waiting for a repeat showing of the European Nightjar they had seen over the Open Air Theatre yesterday evening - an amazing record. Tonight's performance was cancelled, with the bird a no-show, and instead we were treated to the rather lamer spectacle of eight Red-crested Pochard chasing each other around high in the sky as the light faded. Good to have met Adrian Morgan, however, and learnt some more about London's Peregrines. Year-list totals as of tonight:

Rainham
129. Grasshopper Warbler.
130. Arctic Tern.

Alexandra Park
69. Black Redstart.
70. Common Whitethroat.
71. Swallow.

London
169. Grasshopper Warbler.
170. Wood Sandpiper.
171. Black Redstart.

Below: the business, or what? Breeding-plumaged Grey Plovers at Rainham today.

Sunday, 9 May 2010

Waders on the move

Top: breeding-plumaged Dunlin and Redshank on the Purfleet foreshore. Bottom: five of the 13 Whimbrel roosting on Purfleet scrape over high tide.

I was going to give Alexandra Park a thrash this morning, but having done a circuit of the best sites yesterday afternoon and seen nothing, Rainham seemed a better bet - particularly in view of the continuing north-easterly wind and cloudy skies. This weather combination yesterday produced an influx of Wood Sandpipers and other waders in London, and had been the cause of speculation in the Birdwatch office that a vagrant shorebird from the continent was likely to put in an appearance. In the event, Saturday's headline news of a potential first Western Palearctic House Finch in Cornwall wasn't quite what was expected.

I arrived at Aveley Bay full of hope, but that quickly dissipated when I found the car park full of vehicles. Fishermen were dotted along the saltmarsh, so the near part of the bay was entirely birdless. Damn. A scan of more distant mud revealed a party of four Common Sandpipers, so I persisted and checked the far foreshore. Ten mainly chestnut Bar-tailed Godwits were a further bonus, and spring's first Yellow Wagtail flew over calling. Things were looking up.

I didn't have long so spent most of my time until mid-morning wader-watching along the foreshore, eventually homing in on a brick-red calidrid among the Dunlin far away on the Kent side. It seemed barely bigger than its congeners at first so I hoped that it would prove to be a Curlew Sandpiper, but as sun broke through the cloud and I watched it feed, it became clear it was a Knot, albeit a small one.

The morning's final shorebird haul was 13 Whimbrel, Curlew, 10 Bar-tailed Godwit, four Redshank, 16 Ringed Plover, several Northern Lapwing, six Dunlin, Knot, four Common Sandpiper and Oystercatcher, while Ruth Barnes and others added Common Snipe, three Little Ringed Plovers and Turnstone. Also noted were three Little Egrets, 10 Common Terns, two Cuckoos, two Yellow Wagtails and a female Northern Wheatear.

Just to say I told you, this afternoon's big news is an Oriental Pratincole in Lincolnshire. It missed Rainham by more than 100 miles, but who knows what tomorrow will bring?

Saturday, 8 May 2010

Mistaken identity

Show me a birder who claims not to make mistakes, and I will show you a liar. All of us get an ID wrong once in a while - sometimes it might be a close call, at others it could be a howler. One of the few drawbacks of working on a birding magazine is that any such error that makes it into print is amplified massively. Whatever mistake you have made is there for thousands to see, and however unintentional or understandable it can't be undone in a hurry.

I hold my hand up to say that we were responsible for a few such episodes on Birdwatch in the early years, but fortunately we were not alone. Other magazines have had their share too - from hoaxes like a new Phylloscopus warbler named in honour of the Rarties Committee chairman (British Birds) and a hand-painted model of a vagrant accentor in a Derbyshire garden (Birding World) to simple typos like 'underpants' instead of 'underparts' (Dutch Birding) and numerous photo caption errors affecting many titles.

To remind us all of our vulnerability in these matters, a recent example of this last problem has surfaced in the birding press. One periodical which should remain nameless recently identified a Mediterranean Gull in a photo caption, even ageing it as a second-winter. However, as can be seen here, questions have inevitably been raised about the identification (it's far too dark, for one thing, but the four legs, mane, dark coat and size also don't seem to fit).

Tuesday, 4 May 2010

Off-season gulling

An unseasonal mystery gull at Rainham - comments welcome.

Having downloaded my images from the last two trips to Rainham, I have been looking again at Friday’s oddball gull. OK, it’s not gulling season, and you may not like gulls anyway, but hear me out …

I hadn’t planned to do the tip, but as I drove past the entrance I noticed that refuse was being dumped and bulldozed within easy scanning distance. So I stopped to check quickly the 100+ large gulls in the fray and on the adjacent spoil heaps, hoping for a Yellow-legged for the day list. What I got was something rather different.

The bird is clearly a large gull, either adult or almost so – there are remnant dark markings on the bill tip in these poor images (taken at long range with just a 300 mm lens and 1.4x converter). It is big, obviously more so even than Herring Gull, and in one of the shots it can be seen driving a Herring Gull away.

The tone of the upperparts is an ashy grey, darker than Yellow-legged Gull but not quite as dark as in adult graellsii Lesser Black-backed Gull, which was present for direct comparison. Note that in the open wing shot, the mystery gull appears slightly paler than when perched and than it did in the field. It was always possible to see clear contrast between the black wing-tips and the ashy-grey upperwings. The outer primaries themselves seem worn, but even allowing for this there is very little white visible, apparently ruling out what might be the most likely candidate, nominate argentatus (or ‘Scandinavian’) Herring Gull, which often looks appreciably bigger than argenteus but which, though darker than that subspecies, is also slightly lighter in mantle colour than this bird seemed. There is a small white mirror on P10, and the black of the wing-tip appears to extend to P6 at least.

One curious feature of the upperwing is the rather broad white trailing edge to the secondaries, obviously visible even at range. It is less visible on the inner primaries, though because these are more spread in the open-winged shot that may be something of an illusion. The legs were pinkish.

One possibility could be a hybrid, perhaps Great Black-backed x Herring Gull – this rare combination might account for the upperpart colour and obvious white edge to the secondaries, but does the bird show enough white in the outermost primaries, bearing in mind the former’s usually extensively white P10 and white mirror on P9? The only other wing-tip/upperpart colour combinations that approach this seem to be those of Slaty-backed Gull and occidentalis Western Gull, possibilities too outrageous to take seriously … and anyway, structurally can they even be considered?

Back on planet earth, I will look for this bird again, with the 500 mm lens next time and up close. But experience says a repeat showing is probably unlikely, especially in spring with large gulls now shipping out of the Thames en masse. In the meantime, all comments as to its likely identity/parentage are welcome.

Sunday, 2 May 2010

Mixed fortunes

Four of the 12 Bar-tailed Godwits that dropped in at Aveley Bay this morning in heavy rain.

Pouring rain and strong north-easterly winds can only mean one thing: it's a spring Bank Holiday. It was sheeting it down at 6.20 am this morning, but with an easterly element to the poor weather meaning the possibility of a 'seawatch' at Rainham, I headed down to the Thames.

Just before I got to Aveley Bay to check the mud a timely call from David Bradnum told of 11 Bar-tailed Godwits there - a good omen, surely. He had gone when I arrived but the birds were still present, along with a further Bar-tail, five Dunlin and a Common Sandpiper. No sooner had I set the scope up than - bingo! - three cracking summer-plumaged Black Terns came across the river. I rang David, now at the reserve centre with Andy Tweed, and they picked up two of the birds from there. By the time I joined them and Jono Lethbridge for a session on the balcony, several Arctic Terns had flown by - but they had forgotten to call me!

Bob Watts then phoned with the relatively earth-shattering news that London's second-ever American Golden Plover was at the London Wetland Centre. He and we hummed and haaed about going, but eventually my nerve cracked and Jono, Ruth Barnes and I set out in my car - I was going home from there, but David Bradnum would go a little later and bring the other two back to Rainham. The only fly in the ointment of this plan was the unwelcome news, as we steamed along Victoria Embankment in central London, that the bird had flown off high to the west. Grrrr!

Continue or abort the mission? We opted for the latter (sensibly as it turned out), and arranged to meet David instead at King George V Reservoir, where a decent showing of terns made for an appealing rendez-vouz, even if it's not too handy for the City. On our way there, news of a possible Pomarine Skua at the site focused our minds; it had turned into an Arctic by the time we hit Sewardstone, but it was still a cracking London bird. On arrival we exited the car Sweeney-style and I picked it up immediately in the distance over the north basin; Ruth got on it too but the bird vanished before Jono could get a glimpse (apparently it flew over a bank and off to the north, we learned later).

Down at the reservoir shortly after, the terns were showing very well: 49+ 'commics' included at least 15 definite Arctics and a Common, but better still was a smart and close Little and up to three Blacks (all found earlier by Ian Lycett and others). And to cap off the morning, while tern-watching news broke of a singing Wood Warbler up the road at Fishers Green, a capital scarcity which the three of us duly nailed (thanks to Roy Woodward), along with Garden Warbler and Nightingale singing in the background.

The Black Tern was Rainham year-tick number 127, while London year-list additions today were as follows:

162. Black Tern.
163. Arctic Skua.
164. Arctic Tern.
165. Little Tern.
166. Garden Warbler.
167. Wood Warbler

Common Tern at King George V Reservoir, during a weather-induced movement of four tern species up the Lea Valley.

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