Saturday, 31 December 2011

Out with the old ...

A few of the thousands of European Golden Plover at Cley NWT, Norfolk.

I spent the last three days of the year in Norfolk, but because of family commitments only managed to get out in the field for a couple of hours just before heading back to London for New Year's Eve. Having studiously ignored it on the last two trips up here, I therefore decided to do the decent thing and twitch the Western Sandpiper down the road at Cley. Surprisingly, there didn't seem to be many people looking, but I found it fairly quickly out on Simmond's Scrape; unfortunately it remained rather distant, hence the poor record shots below. Plenty of wildfowl, waders and more to enjoy in the limited time - here's a few pics to sign off with until I get out and about in 2012.
Cley's long-staying Western Sandpiper was conveniently present on arrival ...
... but always remained distant, and then flew even farther away!
One of the numerous Black-tailed Godwits on Pat's Pool.
An aberrantly marked dark-bellied Brent Goose among the hundreds present on the reserve.

Thursday, 29 December 2011

Gulls galore

Adult gull showing characters recalling the atlantis form of Yellow-legged Gull (or Azores Gull, reflecting the range of true atlantis). This is the second such bird I've seen in London. Note the pattern and density of head streaking.
I managed to squeeze in the last gulling session of the year at my local study site yesterday, and it was well worth it on a number of counts. Top billing potentially goes to the streaky-headed adult Yellow-legged type which was reminiscent of the form atlantis. This distinctive subspecies from the Azores - arguably a potential split - is more strongly streaked on the head than nominate michahellis Yellow-legged Gull in the autumn, often appearing hooded at any distance. I have seen many thousands of atlantis on the Azores over the course of nine visits, and this bird immediately brought their distinctive heavily marked appearance to mind.

Take your pick - a sample of head patterns on atlantis gulls from the Azores.
The pattern of streaking is not the most typical, however, as many (at least those I've seen in October) seem less well marked on the nape and sometimes more so on the 'snout', so that the hood is neater and more 'even' in appearance. However, I have also seen birds like this, and the pattern fits within the description provided by Olsen and Larsson (2003): "In winter (Aug-Nov/Dec), head more strongly patterned than in michahellis, similar to Herring and Lesser Black-backed, but streaking even denser around eye and below gape, but fainter on hindneck. Azores (and a few Madeiran) birds have even stronger head-spotting and look dark-hooded at distance; hindneck sometimes unstreaked. Head is mainly white with narrow dark streaks around eye and well-scattered brown spots on crown, hindneck and ear-coverts (Madeira and Canary Islands populations)."

The red orbital ring is just about visible in this shot, as is the very pale iris.
Also notable about this bird was the mantle colour, which was a distinctly dark ash-grey - edging a little more towards the palest graellsii Lesser Black-backeds (one of which is perched in front, above). Unfortunately, it was not seen in flight, although some images of it preening give an indication of the wing-tip pattern:

The bird wasn't seen in flight, but here's one shot showing some of the wing-tip pattern.
I wonder what this bird would have looked like two months ago? Presumably even more streaked, and by extension more dark-hooded. Some Azores adults are white-headed even in October, as are the great majority of michahellis by December. A photo of a streaky-headed adult michahellis, taken in November in Worcestershire, is mentioned as "extraordinary" on the Gull Research Organisation website. I have already had some interesting feedback from Peter Alfrey and am taking more soundings on variation in michahellis to try and establish whether the Rainham bird could possibly fall within that, or whether it is a better match for atlantis. More soon, I hope.

Adult michahellis Yellow-legged Gull yesterday - in typically white-headed condition in late December.
Among the many other interesting larids yesterday was a striking, long-billed and rather dark first-winter Caspian Gull (below). By amazing coincidence, among all the thousands of gulls in the area, it was also found independently and photographed by Paul Hawkins - small world:

Smart it may be, but this first-winter Caspian Gull is already looking heavily worn on the wing coverts.
A second-winter Yellow-legged Gull assumes the position.

Thursday, 22 December 2011

Quality trash birds

A third-winter Caspian Gull assumes a dominant stance. Note the adult-type wing-tip pattern with long pale tongues on the inner webs of the outer primaries and the extensive white on the tip of P10.
I picked up the same bird again a couple of hours later, circling the throng and eventually drifting south to drop down out of view somewhere near the river. Note the bill shape and pattern, and faint nape streaking.
After the white-knuckle ride that was birding in Colombia at the beginning of the month, it was back to reality earlier this week with a long-overdue gulling session at Rainham tip on the eastern edge of London. I haven't been able to get there much this winter, but knew there have been Caspians around (see Paul Hawkins's blog for in-the-hand shots) and wanted to see what might be in the offing in the new area now in use.

A different Caspian Gull, this one an adult, showed briefly among the thouands of gulls. Most of the time its feet were hidden among the rubbish, but on reviewing a couple of images I realised it was ringed. Unfortunately the code is not readable in the photos, but it will have acquired the ring elsewhere as Rainham birds are colour marked.
The same bird, showing another classic Caspo wing-tip pattern.
The result was an excellent, if cold, wet and muddy, morning among the best pile of stinking filth for miles around. Gull numbers weren't especially high, perhaps in the low thousands between the tip and the river, but in the current mild spell that's to be expected. Black-headed and European Herring Gulls were the most numerous, the latter including many of the larger, darker-mantled Scandinavian subspecies argentatus, and there were also decent numbers of Common and Lesser Black-backed Gulls (both graellsii and a few intermedius), and fewer Great Black-backeds. Best of the bunch by a country mile were three Caspians and a minimum of nine Yellow-legged Gulls (two first-winters, two second-winters, a fourth-winter and probably at least four adults). Also present and correct for another winter was the white European Herring Gull, cruelly immortalised with the ring number SH1T (you naughty ringers).

Caspian or Yellow-legged? The rather rich bare-part colours and pale iris of this bird might suggest the latter, though even on this perched view there looks to be a fair amount of white in the wing-tip ...
... while in flight the boldly white-tipped P10 and presence of pale tongues swings the pendulum towards Caspian. A wing-tip illustration in Olsen and Larsson (2003) suggests Yellow-legged Gull can also show a similar pattern, but I don't know how regularly this is seen on birds in Britain (compare figs 10 and 15 on pp26-27 of that work).
Adult and second-winter Yellow-legged Gulls, flanked by Herring, Great Black-backed and Black-headed Gulls.

Friday, 16 December 2011

Colombia: new(ish) to science

Parker's Antbird, described as recently as 1997, was named in honour of the late Ted Parker.
Colombia represents a challenging frontier for field studies. It may be ornithologically advanced compared to its neighbours, but its huge avifauna, combined with the difficulties of visiting some areas until recently, means that there are discoveries still waiting to be made. Even since my return earlier this month the country has hit the headlines with an unknown hummingbird – not the ‘missing’ Bogota Sunangel, as had been initially thought, but DNA samples have been taken to determine whether it is a hybrid or a new species to science.

The species is endemic to mid-elevation humid subtropical forest in the Colombian Andes.
If it is the latter, it won’t be the first in recent years. Colombia has a thoroughbred pedigree when it comes to new species being described, and in the Western Andes we were lucky enough to observe and photograph one of them. Parker’s Antbird Cercomacra parkeri was formally described as recently as 1997, and named in honour of the late Ted Parker, the legendary American birder whose life was tragically cut short in a plane crash in Ecuador in 1993.

Parker was famously gifted for his knowledge of Neotropical birds, and best known for his skill with vocalisations, making many thousands of recordings which now reside at the Cornell Lab of Ornithology. It seemed that everything he heard was committed to memory and never forgotten, and he was said to be able to identify more than 4,000 species by voice alone. Once, according to his Wikipedia entry, “on hearing a recording of a dawn chorus in Bolivia, [he] realised that one of the sounds was an antwren of the genus Herpsilochmus - but since he knew all the sounds of those birds, he knew he was hearing a previously unknown species. The following year, the new species was discovered”. 

The species is generally far more furtive than these images suggest, lurking in the undergrowth.
Paradoxically, Parker’s Antbird was not discovered in the field or through its unique vocalisations, but in a museum collection. Gary Graves from the Smithsonian National Museum of Natural History, a friend of Parker’s, began studying the differences in skins of antbirds collected at different elevations in Colombia, leading him to conclude that Dusky Antbird was actually two separate species. This view was supported by subsequent field research into the higher-elevation population which became Parker’s Antbird.

Thursday, 8 December 2011

Colombia: some highlights

Singing male Black-crested Warbler - one of the most attractive of Colombia's 12 Basileuterus species.
Among the many component species of the mixed flocks in the cloudforest was Crimson-mantled Woodpecker.
Breathtaking scenery at Rio Blanco in the Central Andes.
1,878 species. Or thereabouts – let’s not haggle about the odd one. There’s no point, as Colombia’s huge avifauna is very much a work in progress and new species are being added with some regularity. 1,878 species and counting would be a better way of putting it, particularly as the number is also taxonomy dependent. The Clements Checklist uses this figure, but the IOC total is actually 1,906, so it’s an imperfect science.

We observed this tiny but impressive male Bearded Helmetcrest at an elevation of about 14,000 ft.
Colombian hummers come in all shapes and sizes - this female White-bellied Woodstar was almost bee-like in jizz.
Whatever the final number, the sheer volume of species in this wonderful country is hard to take in, at least from a Northern Hemisphere perspective. Species-wise, the sum total of a lifetime’s efforts in the Western Palearctic could be knocked off in a three-week tour of Colombia without too much trouble – there’s even talk of 1,000 species being possible in a month.

Bicoloured Antpitta is usually extremely difficult to locate, so we were fortunate to get great views like this.

Also seen at close range in a forest feeding station was the striking Chestnut-naped Antpitta ...
... but seemingly most common of all was Chestnut-crowned Antpitta. The place for views like these is Rio Blanco.
So never having visited before, I felt I was going to be quickly overwhelmed during a short blitz through the country’s Central and Western Andes. As it transpired, the reality was far more enjoyable – well it would be, of course. While most birders go for longer, I was there for a week at the invitation of the tourism authorities to research and write a feature for Birdwatch about the country’s birding potential. Back on the map after major improvements to the security situation, Colombia is open for business again, with a major USP being its status as the world’s number one country for avian diversity.

A rare view in the open of Slaty-backed Nightingale-Thrush, a subtly attractive tropical Catharus species.
Azara's Spinetails were usually first detected on call, but occasionally gave good views.
Greyish Piculet is one of about 85 species endemic to Colombia (depending on taxonomy followed).
The write-up will appear in the magazine in due course (and watch out for a Birding Adventures TV show too), but having just returned I wanted to share a few images from the trip. Getting such a great head-start with the country’s birdlife was only possible through the expert services of Birding Tours Colombia, who organised the itinerary. In particular, I’m very grateful to Daniel Uribe for his help, knowledge and company in the field – he provided a perfect introduction to the birds of the Andes, and I thoroughly recommend the company to anyone contemplating a visit. Maybe a few of these birds will also whet your appetite …

Tourmaline Sunangel was another in the long line-up at hummer central - Rio Blanco.

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