The Stanwick ‘Ferruginous’ Duck

It’s not called ‘Fudge Duck’ for nothing. Closely resembling the real thing, hybrids abound, enticing observers into a ticking temptation trap, in which nothing is quite what it seems …

When the news broke of Ferruginous Duck or hybrid at Stanwick GP, at around midday yesterday, it was clearly a sensible move to throw in that cautionary caveat – the dreaded ‘h’ word – as rare ducks are notorious for carrying rogue genes. Although looking good at first sight, this was one such bird which, upon closer scrutiny, clearly did not pass muster. OK, it could be said it was mainly but unfortunately, not wholly, Ferruginous. The following assessment is based upon published images of the bird and follows the most up-to-date ‘hybrid checklist’ of features given by Reeber (2015).

It is assumed the bird is an adult female on account of the iris being dark brown (paler in juvenile/first-winter). In terms of size, it’s too large for a Ferruginous Duck. Two of the images below suggest it is virtually the same size as a Pochard. It also appears too bulky. Ferruginous Duck is small and any bird close in size to, or larger than, Tufted Duck is likely to be a hybrid.

Female Ferruginous Duck-type hybrid, Stanwick GP, 25th January 2020 (Adrian Borley)
Female Ferruginous Duck-type hybrid, Stanwick GP, 25th January 2020 (Adrian Borley)

Head shape is not perfect for Ferruginous Duck and is similar to Pochard. On close inspection, the head shows two slightly paler brown patches, one at the bill base and one on the rear cheeks, which is strongly indicative of hybridisation with Common Pochard. The bill colouration also indicates a hybrid as the pale subterminal mark extends along the sides of the bill, which would form a ‘U’ shape when seen from above. The subterminal mark should not extend in this way (although many published images of so-called ‘pure’ Ferruginous Ducks show it – including some of Reeber’s – so its validity may be questionable). There also appears to be fine traces of black at the bill base – another hybrid characteristic.

Female Ferruginous Duck-type hybrid, Stanwick GP, 25th January 2020 (Steve Fisher)
Female Ferruginous Duck-type hybrid, Stanwick GP, 25th January 2020 (Steve Fisher)
Female Ferruginous Duck-type hybrid, Stanwick GP, 25th January 2020 (Adrian Borley)

The belly is not sharply demarcated as it should be for an adult and it appears a little smudgy. Also, there appears to be a slight demarcation between the breast and the flanks, which is not right for Ferruginous Duck.

Female Ferruginous Duck-type hybrid, Stanwick GP, 25th January 2020 (Steve Fisher)

All the above features exhibited by this bird indicate a hybrid origin. Reeber suggests that hybrids are relatively frequent in the wild and even goes as far as stating that in Western Europe, hybrid-like Ferruginous Ducks are commoner than pure individuals!

An exciting new addition to the Northamptonshire List

Completing the latest duck race, Falcated Duck makes it over the line … after a third of a century.

It has only taken 33 years but the drake Falcated Duck, which first arrived with Wigeon at Welney in Norfolk in December 1986, before relocating to Pitsford Res in February 1987, has just been accepted by the British Onithologists’ Union as the latest addition to the British List.Found by Dave Burges and Matthew Rodgers on 15th February 1987, it remained at Pitsford until 5th April and the record was duly submitted to, and accepted by, the British Birds Rarities Committee. It reappeared the following winter, when it turned up at Thrapston GP on 12th December, remaining there until 24th, before relocating to nearby Ringstead GP, from where it commuted to and from Thrapston between 16th January and 6th March.

Falcated Duck, Martin Mere, September 2014 (Francis C Franklin/Wikimedia Commons). Captive for illustration only.

Prior to the return to Northants it was present again at Welney during the autumn. An image of the bird appeared in British Birds 80: 255.

Falcated Duck breeds in eastern Siberia and has wandered to Pacific coast USA, south-west Asia, the Middle East and Europe, where occurrences have often been dismissed as escapes. Its population is currently thought to be 78,000-89,000 individuals.

Velvet Scoters in focus

Found on 27th October, a small flock of Velvet Scoters on Thrapston’s Town Lake is the first in the county since 1995 and rightly continues to attract a steady stream of admirers. Widely touted as ‘juveniles’, additional high-quality photos to emerge allow a more analytical approach to ageing, sexing and individual recognition.

The original eight, found on 27th October, had become six by the following day when two distinct individuals, which frequently kept apart from the rest of the flock, had departed. As well as being the largest flock to be recorded in Northamptonshire, the remaining six may also be in line to break the long stay record for more than one bird, having been present now for at least eleven days. The record is currently held by two which were mobile between Hollowell and Ravensthorpe Reservoirs, from 7th to 27th November 1983.

First-winter Velvet Scoters, Thrapston GP, 29th October 2018 (Bob Bullock)

Close examination of the excellent images obtained by Alan Boddington and Bob Bullock enables individuals to be readily identified by their head patterns, which are quite variable. Because of the broad, pale feather fringing on the wing coverts, the ‘long staying six’ (A to F) can be aged as first-winters and at least two of these (B, D) are young males, the dull yellow areas being visible on their bills. None of the other four shows the slightest hint of yellow but C, E and F are showing pale horn-coloured areas on, or around the sides of the nail. This is interesting because, according to Reeber (Wildfowl of Europe, Asia and North America, 1995), this is a characteristic associated with adult females and not present in first-winters.

Adult female Velvet Scoters, Thrapston GP, 29th October 2018 (Bob Bullock)

The ‘short staying two’ (G, H) are adult females with uniform dark plumage, which includes, most importantly, the belly – visible in the only flight shot (below) obtained so far. First-winters have a pale belly until adult plumage is acquired later in the winter or during their second calendar year. Hopefully, the remaining birds will continue their stay at Thrapston for some time to come.

Adult female Velvet Scoters, Thrapston GP, 29th October 2018 (Bob Bullock), birds ‘G’ (left) and ‘H’.
First-winter Velvet Scoters, Thrapston GP, 31st October 2018 (Alan Boddington). Birds ‘C’ (left) and ‘D’.
First-winter Velvet Scoters, Thrapston GP, 31st October 2018 (Alan Boddington). From left: birds ‘A’, ‘D’ and ‘B’.
First-winter male Velvet Scoter, Thrapston GP, 31st October 2018 (Alan Boddington), bird ‘D’.

Ageing process of the Stanwick Pink-footed Goose

Since it was first discovered, the Pink-footed Goose, which has been present with the resident Greylag flock at Stanwick Gravel Pits throughout the winter, has undergone a considerable change in appearance.
Juvenile Pink-footed Goose, Stanwick GP, 12th October 2017 (Steve Fisher)

It arrived as an obvious ‘fresh’ juvenile in October last year. Its overall appearance was scruffy, dull and almost uniform brownish, rather dark-headed and only narrow, dull pale fringes to the scapulars, coverts and tertials. Its bill was also dark, with a dull pink band behind the nail and extending faintly along the cutting edge of the upper mandible. Thanks to images captured by Steve Fisher and Angus Molyneux, it’s easy to see the progression from juvenile to adult-type plumage which has taken place over a matter of almost four months.

Pink-footed Goose, Stanwick GP, 10th January 2018 (Steve Fisher)

By January it had acquired adult-type plumage, with streaked rear flanks, a contrast between upperparts and underparts, broader, whiter fringes to mantle, scapulars and coverts and a brighter pink bill (although lighting may exaggerate differences in photos).

Pink-footed Goose, Stanwick GP, 5th March 2018 (Angus Molyneux)

By March, the bird looks neat and has developed some whitish feathering around the base of the bill, which is found quite commonly in adults.

Clifford Hill Bufflehead goes west

Turning up and performing well in front of the hide at the southern end of Daventry Country Park yesterday, ‘Buffy’ was finally stripped of her celebrity status as she revealed more of that tell-tale ring detail.
Female Bufflehead, Daventry CP, 27th June 2017 (Bob Bullock). An escape from captivity with a non-conformist metal ring on the right leg.

Thanks to some excellent images from Bob Bullock, it became apparent that our Bufflehead’s ring format does not conform to any which is used in either Canada or the USA – either now or in recent history. Digits around the centre of the ring include random numbers 38, 58, 60 (or 09) and there is no alphanumeric contact detail in smaller text above or below these numbers.

Female Bufflehead, Daventry CP, 27th June 2017 (Bob Bullock). An escape from captivity with a non-conformist metal ring on the right leg showing number 58.
Female Bufflehead, Daventry CP, 27th June 2017 (Bob Bullock). An escape from captivity with a non-conformist metal ring on the right leg showing numbers 38 and possibly 09.
Female Bufflehead, Daventry CP, 27th June 2017 (Bob Bullock). An escape from captivity with a non-conformist metal ring on the right leg.

I am grateful to Chris Wood of the Cornell Lab of Ornithology, Ithaca, New York who, upon receiving copies of the above images, kindly commented as follows: “Honestly, I can’t imagine this ever being used by a researcher here. Bands have been standardized for a long time now and this just doesn’t look like anything we would use.”

Danny Bystrak, Wildlife Biologist at the Bird Banding Lab, Patuxent Wildlife Research Centre near Washington, USA, also commented: “The band looks narrow and over-sized is not something I have ever heard of anyone using in the US or Canada.” [via Chris Wood]

So, there we are. Our Bufflehead has indeed gone west … along with any chance of it being a new bird for the county.

Postscript: it is reportedly back at Clifford Hill GP today.

More on the Clifford Hill Bufflehead

The lady shows her ring …

… but the detail is indiscernible. I spent some more time with the Bufflehead this afternoon, hoping to see some ring detail – any ring detail – which might help shed some light on its origin. At one point, it came out of the water and stood on the bank but its visit to land was all too brief and, before I could get the scope focussed for a digiscoped shot, it was off again and back into the water. It’s also difficult to capture any decent images or video as, most of the time, it seems to be very active, constantly diving and spending 80%-90% of its time below the surface.

However, I did manage some more video, from which I took a series of grabs showing the ring, which appear below. Image A would suggest there is some inscription in the middle section of the ring, but this is far from certain. Blow-ups don’t help, either.

Female Bufflehead, ring on right leg, Clifford Hill GP, 25th June 2017, videograb.

For comparison, here are two videograbs of the 2015 Bedfordshire bird, which was also ringed on the right leg. The proportions of the rings look similar but may not be.

Drake Bufflehead, ring on right leg, Priory CP, Bedfordshire, 29th October 2015, videograb (Mike Alibone)
Drake Bufflehead, ring on right leg, Priory CP, Bedfordshire, 29th October 2015, videograb (Mike Alibone)

They also appear to be similarly proportioned to Canadian duck rings, also illustrated below. None of this actually means, or proves, anything, of course, but it would be nice to get to the bottom of where this bird actually originated.

Persistence is required, waiting for the next time it sits out on the bank … Interestingly more Buffleheads have been seen in June than in any other month and in central England than any other area in the UK. Thanks to Andrew Cook and Mark Hill for pointing this out (source: Rare Bird Alert).

Northamptonshire’s first Bufflehead?

With some potentially serious negatives against it, what is ostensibly the first Bufflehead for Northants is likely to be an escape … or is it?

Late this morning, Terry O’dell discovered what later proved to be an adult female Bufflehead on the south side of the main barrage lake at Clifford Hill Gravel Pits. It was still present this afternoon, during which I managed to obtain some rather poor quality, wind-shaken, digiscoped video.


There have been two individuals deemed escapes reported recently: a yellow-ringed bird in Norfolk in April and a (presumed) metal-ringed bird in West Yorkshire last month. The Clifford Hill bird is metal-ringed on its right leg and, along with its having appeared in June, the odds are rightly stacked against it being a wild individual. Or are they?

Bedfordshire, 29th October 2015

Here are a few facts resulting from my research into the escape likelihood of the one in Bedfordshire in October 2015. I’d spent some considerable time looking at the Bedfordshire Bufflehead ring and doing some research.

Bufflehead, Priory CP, Bedfordshire, 29th October 2015 (Mike Alibone) and examples of American rings.

I have a contact who produces a lot of video material for the BBC and I sent him some footage to see if he could freeze the ring on my video of that bird better than I could. He tried but couldn’t. The characters on the ring appeared to occupy a good 50% of the depth of the ring and appear just as a dark area. Any smaller characters above or below, if they exist, are invisible. The format could match one or two of the smaller rings in the image attached, lifted from http://www.duckbands.com/ an American site.

I also spoke to James Lees at length about it. His view from a ringing perspective was that it was more likely to have been ringed in the wild than in captivity because most collections use plastic rings, not metal, and he believes that Slimbridge is the only collection (he knows of) which uses metal rings (same format as BTO rings) for individual ID because their collection is extensive and because they move birds around to other collections to breed and keep the gene pool healthy. He also pointed out that American-ringed ducks have been seen in the UK before and that they once had a ringed Ring-necked Duck visit from the states and it ultimately found its way back across the Atlantic, and was seen again in Newfoundland after leaving Slimbridge. All this I guess we know …

So, what we have for the pro-wild camp is:

  • Metal ring, indicating higher likelihood of wild than captive origin
  • Ring format could match that of Nearctic-ringed bird
  • 22.5 thousand Buffleheads ringed in Nearctic between 1951 & 2011
  • Buffleheads can live for 18 years (OK if it’s an adult drake coming out of eclipse)
  • October is the peak migration month for Bufflehead in the USA
  • The bird stayed for one day only and, so far, has not been reported anywhere else
  • No birds missing from local collections (but doesn’t rule out an escape from further afield)

And for the pro-escape camp:

  • It had a ring of any type

That’s my analysis concluded. Read into it what you will but unless it’s seen to haul itself out on to the bank or an island, where the ring can be properly seen, we’ll never know for sure.

 

Hybrid Wigeon

This very striking drake, found yesterday on Earls Barton GP’s Mary’s Lake by Kim Taylor, looked initially like it might be an American Wigeon x Eurasian Wigeon hybrid but it soon became clear it is actually a Chiloe Wigeon x Eurasian Wigeon.

Chiloe Wigeon x Eurasian Wigeon hybrid, Earls Barton GP, 14th November 2015 (Bob Bullock)
Chiloe Wigeon x Eurasian Wigeon hybrid, Earls Barton GP, 14th November 2015 (Bob Bullock)
Chiloe Wigeon x Eurasian Wigeon hybrid, Earls Barton GP, 14th November 2015 (Bob Bullock)
Chiloe Wigeon x Eurasian Wigeon hybrid, Earls Barton GP, 14th November 2015 (Bob Bullock)
Chiloe Wigeon x Eurasian Wigeon hybrid, Earls Barton GP, 14th November 2015 (Bob Bullock)
Chiloe Wigeon x Eurasian Wigeon hybrid, Earls Barton GP, 14th November 2015 (Bob Bullock)

It’s an amazing-looking bird which matches known hybrids. A potential pitfall for American Wigeon, perhaps, but green area too extensive, crown yellowish and inextensive and flanks heavily suffused grey.

Chiloe Wigeon x Eurasian Wigeon hybrid, Earls Barton GP, 14th November 2015 (Bob Bullock)
Chiloe Wigeon x Eurasian Wigeon hybrid, Earls Barton GP, 14th November 2015 (Bob Bullock)
Eurasian Wigeon, Earls Barton GP, 14th November 2015 (Bob Bullock)
Eurasian Wigeon, Earls Barton GP, 14th November 2015 (Bob Bullock)

But what would it look like in eclipse? Check the axillary colour: white in American, grey in Eurasian and in this individual, as Bob’s images, above, so neatly illustrate.

Juvenile male Garganey

With most having long departed for Africa, there are probably fewer than ten Garganeys left in the UK at present. I first found this one at Ravensthorpe Reservoir on 20th September and, though not reported for a couple of weeks in late September/early October, it has a poorly marked face pattern and is readily identifiable as the same individual. It was still present yesterday. Juvenile male Garganey, Ravensthorpe Res, 19th October 2015 (Mike Alibone)

To my eyes, juvenile Garganeys stand out from the crowd of Teal – with which they often loosely associate – even when the face pattern can’t be seen. That combination of dark, oily-rust breast and flanks, contrasting sharp, whitish edges to the tertials and no white line along the outer edge of the under tail coverts is really quite eye-catching. The feeding habit of swimming around with the head partly submerged and rarely up-ending like Teals do is also a useful initial pointer. Garganey - Copy (2)                                                                                                  This particular individual is clearly a juvenile based on plumage tone and the solid dark belly (female and eclipse drakes have a whitish belly) but a quick flap of the wings, revealing a greenish speculum bordered by very broad white borders, was enough to sex it as a male.

In the accompanying, rather ropey, video there also appears to be the beginnings of a male breast band – demarcated from the belly – coming through. This does not appear to be mentioned in the literature as appearing quite so early on in the autumn but I guess it has to start sometime.

As it’s been present for a month it will be interesting to see how long this bird stays around. Wintering birds are rare but not unheard of!