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Wednesday, 27 August 2014

Yet another BLUE-WINGED TEAL hybrid

Took a trip out west yesterday to twitch Brian Stretch's eclipse BLUE-WINGED TEAL in Worcestershire at Grimley New Workings, just east of the A443. It was drizzling as I arrived and the bird had been flushed off by a dogwalker. I decided to investigate and after soliciting local expertise, followed a footpath down into the valley to check the pools further along. It didn't take long to relocate the bird, as it was feeding on mud on the south shore with Mallard. I was immediately struck by the bill size and shape and a number of plumage anomalies, the bird bringing back instant memories of the last Blue-winged Teal I successfully twitched in the Midlands - at Daventry Reservoir (Northamptonshire). I took a number of shots of the bird from my position on the north shore but they were distant and grainy, so I then decided to carry on and walk right round. Relocating it there, it soon became apparent that this was a hybrid, almost certainly a Blue-winged Teal x Northern Shoveler - certainly on size. The bird kept moving away in front of me and back towards the crowd at the far end but eventually I managed to get some reasonably decent shots of it (see below). As soon as I realised it was a hybrid (between Blue-winged Teal and Northern Shoveler), I informed RBA and attempted repeatedly to contact Steve Whitehouse (Birdline Midlands) but he was out of phone reception in the Forest of Dean. Blue-winged Teals and Shovelers seem to hybridise quite freely proving that they are extremely closely related and there have been several cases of mixed pairings in this country (including a female that nested successfully in Cambridgeshire for a number of years).

Here are my images -:












I gradually coerced the Teal into flying back towards the crowd, where it landed in good view in front of them. I then walked back and informed them of my beliefs but few of them seemed interested and were intent in calling it a 'Blue-winged Teal'. Once home, I sent my images to Chris Heard and Keith Vinicombe, both agreeing with my synopsis.

This is what Keith had to comment - 

''Lee, well, if I saw this at Chew I would probably have overlooked it as a Shoveler! The bill looks huge. The only thing that looks slightly odd to me are the noticeably paler lores and the paler eye-ring. In the second photo, the facial pattern and facial expression are certainly very reminiscent of BWT.But, bearing in mind that all species vary individually, I wouldn't even like to say for sure from these photos that it's a hybrid. If it is a hybrid, then of course Shoveler x BWT or Shoveler x Cinnamon Teal would be the obvious options - but I would have thought that a hybrid would have been obviously on the small side compared with Shoveler. Of course this is easier to judge in the field in comparison with other ducks. It's certainly not a pure-bred BWT''.

Wildfowl expert Chris Batty has raised the spectre of female CINNAMON TEAL into the equation, Keith Vinicombe kindly providing these images -:




I must admit, it's a difficult call - little to choose between them (LGRE)



Friday, 15 August 2014

A remarkably confiding LONG-TAILED SKUA

On Saturday 2nd August, local birder Andrew House photographed a small skua harassing Sandwich Terns at Church Norton, in Pagham Harbour (West Sussex). He obtained several record shots of the bird and over the next few days of its presence, these were uploaded onto Andy's local Pagham Harbour blog site on the web. Sharp-eyed David Cooper noticed these and questioned the identification and with better insight and improving images, Andrew and others were able to confirm its identification as LONG-TAILED SKUA on Tuesday 5th August. Since then, the bird has been seen daily, patrolling the beach between the new Medmerry RSPB reserve west of Selsey Bill to Church Norton to the east. Much more recently, locals have discovered that it is returning to roost high tide on the shingle halfway between Church Norton and Selsey East Beach Lifeboat Station, generally spending up to 3 hours there if not disturbed - usually in line with the last 3 bungalows on the Selsey Peninsular. Once roosting, the views are astounding and a spectacle to be cherished. The bird is a sub-adult, with retained barring on the underwing coverts.

Although I have now seen it on 5 occasions over 7 visits, yesterday's visit was an undoubted climax - the bird performing just a few feet in front of me for over 3 hours. Please browse a selection of over 2,000 images I obtained of the bird below. To see the bird, allowing an hour either side of high tide, park by the church at Church Norton and walk half a mile south to the shingle beach in line with the first few beach bungalows.
























































Long-tailed Skua, Selsey Peninsular, West Sussex, 14 August 2014 (Lee G R Evans)



Long-tailed Skua, Selsey Peninsular, West Sussex, 14 August 2014 (Mick Davis)

The fact that the bird is retaining barring in the underwing coverts (see Mick's superb images immediately above) indicates that it is most likely a fourth-summer (in its fifth calendar-year).

Long-tailed Skua is the smallest and most graceful of the skuas - a lightweight by comparison. It is about the size of a Black-headed Gull and has a shorter and rounder head and longer and narrower body and tail, appearing triangular and tapering behind the slender wings. The breast is deep and the belly flat, the tail longer than the width of the arm. The wings are narrower than those of Arctic Skua and the short head is accentuated by the short and rather heavy bill (proportionately). The outer wing shows just 2 (occasionally 3) pale primary shafts in the upperwing, forming a narrow but complete pale line on the forewing, has two-toned upperwings and lacks a primary patch below (in anything apart from juveniles). The flight is more lightweight than that of Arctic Skua's, with weaker wingbeats and far more gliding. They often glide shearwater-like for several hundred metres without flapping and have a propensity to hunt insects, often at considerable height or over fields. 

Long-tailed Skuas in adult form occur only as pale morph. The concolorous dark cap and bill create a black helmet against pale neck sides and breast. This pale breast gradually shades into a grey belly, the rest of the undersides being a darker brown. The upperparts are bi-coloured, being pale brownish-grey with contrasting black flight feathers and tail - the tail projection being much longer than in the other skuas - the central feather pair extending far beyond the rest of the tail. From late summer however, these central feathers are often broken off, and by September, are invariably missing. The tarsi are mostly bluish-grey, again unlike that of the dark colour of adult Arctic and Pomarine Skuas. A full adult (eg, a bird in its 6th calendar-year or above) has an all-dark underwing, some barring being attained by adults in their 3rd, 4th and 5th summers.

The moult of an adult Long-tailed Skua is completed on arrival at the wintering grounds between October and December. A minority (probably failed breeders) start in July with minor parts of the head and mantle.

References

Olsen & Larsson 1997, A Guide to Skuas and Jaegers of the World