Sunday, 29 January 2012

Hampshire and back

A close-up of the adult Ring-billed Gull in Gosport, a regular returning bird. Where does it go in summer?
The main venue for today's birding was Hampshire, a favourite county of mine, although two species on the target list are more typically associated with New Hampshire across the Atlantic.

With the presumed demise of the returning winterers in London and Westcliff-on-Sea, the Gosport Ring-billed Gull is now the only regular bird left in the South-East. Indeed, the species has become rarer nationally in recent years.
The first was this Ring-billed Gull, which is a regular wintering bird at Walpole Park in Gosport. I've seen it before but not for a few years, and wanted to spend some time photographing it as part of building my library of gull images (and plumages). I actually saw the bird in flight over the boating lake before I'd even stopped the car, but it promptly disappeared west out of view so I set off on foot in pursuit.

Ring-billed and Mediterranean Gulls: how often do these species from different continents meet up?
It was just after I relocated the Ring-billed on mud in the creek next to Walpole Park - conveniently next to a smart Mediterranean Gull at one point - that I also came across a real bonus bird in the form of an Iceland Gull. Distant at first among other larids on the far side of the creek, it eventually came closer and I was able to get some decent images. Also present were 30+ dark-bellied Brent Geese, two Little Egrets, Eurasian Curlew, Black-tailed Godwit and Rock Pipit.

Unexpected: this second-winter Iceland Gull was a real bonus bird.
Returning to the boating lake in the park, my investment in a loaf of Hovis medium sliced was then repaid when clouds of gulls arrived to feed. The Ring-billed was among them, and it was great to get the hoped-for closer shots in flight and on the deck - job done.

I headed west from Gosport to take the M3 home, making a short detour en route to take in the Dark-eyed Junco currently residing in the New Forest at Hawkhill Inclosure. I had to wait a while for the bird to appear, as it seemed to be roving around a large clearing with a flock of Reed Buntings, but in the interim several Common Crossbills (including a song-flighting male) and Eurasian Siskins were nice diversions. Eventually the bunting flock reappeared and with it the junco, which then came in to feed for a few minutes. It's the third I've seen in Britain but the first for more than 20 years, and the most photogenic.

The first-winter Dark-eyed Junco at Hawkhill Inclosure - a smart bird.
After an easy drive north back to the capital, I broke the journey one last time at Staines Reservoirs. The very first bird I saw on reaching the causeway was the long-staying European Shag - a good London bird - swimming close to the water tower, so I watched and photographed it for a good 10 minutes before it flew off to feed elsewhere on the reservoir. Also present were Great Northern Diver, Greater Scaup, two Black-necked Grebes and a male Ruddy Duck - the latter arguably the rarest bird of the day.

European Shag at Staines Reservoirs, feeding actively ...
... and then photographed in flight as it headed off elsewhere on the reservoir. 

Saturday, 28 January 2012

Important: Rainham landfill site

There have been problems recently at Veolia's Rainham landfill, which unlike the adjacent RSPB reserve and riverside footpath is a private industrial site to which public access is not permitted. On three recent occasions birders have been found trespassing; one incident apparently involved 10 people on the site without permission.

Anyone who wants to watch gulls in the area should stay outside the landfill perimeter at all times and enjoy the excellent birding on the clearly marked riverside pedestrian and cycle path that circumnavigates the site. In fact, larger numbers of gulls are often present near the tip rather than on it, either on the river, foreshore or RSPB reserve (particularly Wennington Marsh), all areas which are easily accessible or viewable. It is here that the recent Glaucous and both Iceland Gulls were found, not on the landfill itself, and indeed last winter’s Slaty-backed Gull was found and twitched outside the tip.

Please would everyone visiting Rainham therefore keep to public areas. Any further problems may result in access difficulties for the very small team who, with kind permission from the site owner and with health and safety training, are periodically allowed to visit the landfill to ring and monitor gulls. Rainham landfill is a working site with dangerous machinery and hazardous substances constantly in operation – please do not put yourself or the goodwill of the site owner at risk.

Monday, 23 January 2012

Wrong side of the river

Tale of the unexpected: an American Mink is mobbed as it breaks cover in Thamesmead, south-east London.
I made a rare trip across the Thames to ‘sarf’ London today, mainly with the aim of seeing the second-winter Iceland Gull at Crayford after a tip-off from Kev Jarvis. In that ambition I failed, the gull departing before I arrived on site. A fly-by first-winter Yellow-legged Gull was scant consolation, but having then heard from Kev that Rich Bonser’s Ferruginous Duck at Thamesmead had been seen again, I duly set off in pursuit.

It’s been some time since I navigated my way around the back streets of Thamesmead, as a result of which I eventually ended up at Thamesmere Lake East. There was no sign of the Ferruginous Duck, a fact that became less surprising when John Archer helpfully tipped me off that it actually frequented Thamesmere Lake West. While at the east lake, however, I caught sight of a small animal scurrying along the far bank of the lake. Getting the bins on it, I quickly realised it was an American Mink – a species I haven’t seen in the wild previously in Britain.

This introduced predator is a serious problem for breeding waterbirds and small mammals.
The mink forages along the lake bank before disappearing in dense vegetation.
As the mink broke cover and ran along a concrete wall, Black-headed Gulls and Carrion Crows immediately gathered to mob it. The creature foraged briefly along the lake bank before disappearing into deep vegetation. While pleasing to see something unexpected, it was at the same time alarming – American Mink are voracious predators, their presence often being associated with catastrophic declines among Water Vole populations and damaging impacts on gull and tern colonies, even on offshore islands.

Interestingly, it is the second sighting of this species along the Thames in London this month, Dave Morrison having photographed a different mink at Beckton Works just across the river. Hopefully, measures will be put in place to control this introduced predator, or the consequences for local wildlife could be severe. 

White-fronted Geese in the Ingrebourne Valley.
After that distraction I arrived late at the neighbouring lake, with the Ferruginous Duck having now retreated out of view into the reeds (as it apparently likes to do). My first Common Chiffchaff of the year and a couple of calling Water Rails were the only notable species, so I headed back to Crayford, failed again with the Iceland Gull (though this time had second-winter and adult Yellow-legged Gulls) and cut my losses by heading north through the tunnel. Saving the day bird-wise were two White-fronted Geese in the Ingrebourne Valley, always a good species to see in London (thanks to Dave Mo for the tip-off).

* Footnote: researching American Mink subsequently, I was amazed to learn that one recent estimate put the British population at 110,000 (England 46,750, Scotland 52,250 and Wales 9,750 – Mammals of the British Isles by Harris and Yalden, 2008). I don’t know the species’ status in London – comments welcome.

Monday, 9 January 2012

Where there's muck ...

I could think of no better way of spending last Friday than being surrounded by gulls for hours on end. With a major influx of Iceland and Glaucous Gulls taking place after last week's Atlantic storms, I was hoping for a white-winger locally, but in the event it was Caspian and Yellow-legged Gulls that provided the main interest. At least four of the former comprised a first-winter, a third-winter, a fourth-winter and an adult, with the last two both being ringed. The fourth-winter bird was gold-on-green 355P, ringed as a chick in Poland and found by Jonathan Lethbridge and I at Rainham RSPB 14 months ago but not seen there since - great to have it back for another winter.

Back for another season, this fourth-winter Caspian Gull was ringed as a chick in Poland in 2008.
Note the distinctive primary pattern with largely white-tipped P10, big white mirror on P9, grey tongues on P8 and P9 and solid black band on P5. The primary coverts still have residual black markings.
The adult Caspian was the metal-ringed bird I saw last month. Despite getting close shots of it, however, I haven't been able to read any meaningful ring detail - if you can make anything out from these images, please post a comment. I suspect it was ringed overseas, not least because most gull-ringing schemes over here seem to colour-mark birds.

Yellow-legged Gulls were almost constantly present, and I decided to photograph every bird for a complete record. I estimated at least 14 individuals across all age classes, but having sifted through more than 900 images and compared fine bill and plumage detail, I was surprised to discover a minimum of 24 birds - four first-winters, nine second-winters, four third-winters and seven fourth-winters/adults. The range of variation within each age class was also surprising, and when time permits I will post a selection of images.

Plenty of other interest included an adult graellsii Lesser Black-backed Gull from a new ringing scheme (details hopefully to follow), and a very streaky-headed third-winter Herring Gull with a strong brown wash to the greater coverts, grey tongues to at least P8 (probably to P9, not sure about P10), a solid black band on P5 and a rather heavily marked blackish tail band for its age. As is so often the case with gulls, plenty of follow-up research to do ...

Third-winter Herring Gull with heavy head streaking and brown-washed greater coverts ...
... note also the primary pattern and blackish tail band at this age.
UPDATE: It was subsequently suggested that the metal-ringed adult Caspian Gull featured above may have originated from the Ukraine or Russia, but more recently it appears that it may have actually been ringed 13 miles east along the Thames at Pitsea, when it was mistaken for a Herring Gull (per Steve Arlow).


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