Age and subspecific ID of Summer Leys Black-tailed Godwit

One for the analytically-minded …

A Black-tailed Godwit has been present on the scrape at Summer Leys LNR since 22nd March and by all accounts, it’s still present today. Because of its rather drab colouration, it seems to have attracted little interest – after all, it’s not the type of super-rusty, spangled-mantled individual which usually finds favour with photographers. So, let’s take a closer look.

First-summer Black-tailed Godwit, Summer Leys LNR, 24th March 2021 (Mike Alibone)

Its overall grey appearance suggests three main possibilities: it’s an adult which has not yet developed full summer plumage, it’s an adult which has attained summer plumage but remains largely grey, or it’s a first-summer which will not develop full summer plumage this year. It also raises the question, which race is it?

Probably 99.9% of the Black-tailed Godwits passing through Northants are of the Icelandic race, islandica. In full summer plumage they are extensively rusty below and spangled rusty-chestnut and gold on the upperparts – more so in males. The much rarer ‘Continental’ Black-tailed Godwit of the nominate race, limosa breeds in very small numbers in the UK, no further away than the Ouse Washes. They are less extensively and less intensively coloured, frequently being much greyer (especially females) and subtly structurally different, i.e. generally longer-legged, longer-necked, with broader-based, longer bills. For an excellent, detailed, in-depth analysis, see the definitive paper documenting 30 years of study by Mark Golley here.

First-summer Black-tailed Godwit, Summer Leys LNR, 24th March 2021 (Mike Alibone)

So, on a closer examination of our Summer Leys bird, it becomes immediately apparent that it’s not uniform grey. There’s an area on the wing, which is lighter and zooming in through a telescope, this light area can be identified as very worn and faded coverts, which look quite pointed and ‘tatty’. These are old juvenile coverts, which may be retained for up to 12 months, becoming worn, while the remainder of the body plumage is, in comparison, fresh, non-juvenile plumage. The tertials are similarly worn.

First-summer Black-tailed Godwit, Summer Leys LNR, 24th March 2021 (Mike Alibone)

This puts the bird in the first-summer age group, which will not have developed conventional adult summer plumage. Easy on good views. But what about race? That’s a little more tricky. As far as structure is concerned, the legs are largely hidden (although the tibia looks short), the neck and bill do not seem overly long, nor does the bill look particularly broad-based, although from different angles all these features appear to vary, as evidenced in the accompanying images. On balance it does not stand out as being an obviously large, lanky individual. However, it may be a male – which is smaller and shorter-billed than a female.

First-summer Black-tailed Godwit, Summer Leys LNR, 24th March 2021 (Mike Alibone)
First-summer Black-tailed Godwit, Summer Leys LNR, 24th March 2021 (Mike Alibone)

Though assessing the structure is tricky, the clue lies in the plumage. Zooming in again reveals the feather colouring of the few adult-type feathers which have emerged on the scapulars being the rather orangey/gold and black of islandica – versus the pale yellowish and black of limosa – and there is even one very ‘chestnutty’ one showing, while those on the breast, where colour is visible, are rather dark rufous-chestnut instead of limosa’s paler rusty wash.

First-summer Black-tailed Godwit, Summer Leys LNR, 24th March 2021 (Mike Alibone)

So, after a bit of detective work, there we have it: first-summer Icelandic Black-tailed Godwit. There’ll no doubt be many more of these godwits to come as we move deeper into spring and early summer.

A touch of the continental

Limosa Black-tailed Godwit at Summer Leys

On the evening of 13th May, Leslie Fox emailed me an image of a Black-tailed Godwit he had seen at Summer Leys LNR during the afternoon. It was immediately apparent that this did not look like one of the ‘usual’ Icelandic race (islandica) birds we see passing through the county in some numbers each year and blowing up the images revealed a number of characters which were inconsistent with the latter race.

‘Continental’ Black-tailed Godwit, Summer Leys LNR, 13th May 2020 (Leslie Fox)

The most striking differences were the complete lack of the extensive rufous ‘tapestry’ of mantle feathers found in typical islandica and the abrupt ending and confinement of rusty feathers to the upper breast and neck. Blowing up the image further revealed a very limited number of broad, warm yellowish-fringed, black-centred feathers scattered on the mantle and the tertials appeared plain and unnotched – both features associated with limosa and not normally exhibited by islandica. Further pro-limosa features were the relatively long, broad-based bill and subtly sloping forehead. The lack of contrast between the wing coverts and the mantle indicated the bird was an adult.

‘Continental’ Black-tailed Godwit, Summer Leys LNR, 13th May 2020 (Leslie Fox)

‘Continental’ Black-tailed Godwit, Summer Leys LNR, 13th May 2020 (Leslie Fox)

‘Continental’ Black-tailed Godwit, Summer Leys LNR, 13th May 2020 (Leslie Fox)

Although the bird was not seen again on 13th, it was still present mid-late afternoon on 14th. Upon request, Leslie sent me some more images before I managed to connect with it on the morning of 15th in an attempt to get to grips with the features in the field. The bird was long-legged and reasonably long-billed (both pro-limosa features) but it was relatively small and its bill was not excessively long, so I concluded it was likely to be a male (females are large and normally very long-billed).

Pleased to have seen it – albeit quite distantly – I sent Leslie’s images off to the ‘Godwit Guru’, Mark Golley, who has probably more experience than anyone else in the UK in limosa godwit identification, which he has distilled into a lengthy paper Notes on the field identification of nominate Black-tailed Godwits in Norfolk.

Many thanks to Mark for providing feedback and comments as follows:

 

Temptingly Tundra

A close look at some of the migrant Ringed Plovers passing through Northants in autumn would suggest they are from further north than the race which breeds in the UK.

The fact that we get ‘Tundra’ Ringed Plovers on passage in small numbers during late spring is well established (see here and here). As juveniles in autumn they are perhaps less obvious and characters vary as differences are clinal but some readily exhibit certain pointers which suggest they are not the nominate race hiaticula.

At least two such individuals have been present at Boddington Res since 29th September and are still present today. To my eyes they stand out as being different – so much so that they have even been reported by some observers as Little Ringed Plovers.

Presumed ‘Tundra’ Ringed Plovers, Boddington Res, 2nd October 2018 (Mike Alibone)

‘Tundra’ Ringed Plovers can be one of two races, either psammodroma, which has a breeding range from the Faeroes to north-east Canada, or tundrae, which breeds from northern Scandinavia to Russia, although the validity of psammodroma as a race is contested by some authorities.

Presumed ‘Tundra’ Ringed Plover, Boddington Res, 2nd October 2018 (Mike Alibone)

The Boddington two differ from each other insomuch as one has a narrow, complete breast-band and the other has a broad, almost broken one. While both appear noticeably smaller than ‘our’ Ringed Plovers, they differ from juvenile Little Ringed Plover by the lack of a pale eye-ring, a fairly obvious supercilium and clean white forehead. Of course, when they fly there’s the wing-bar!

Presumed ‘Tundra’ Ringed Plover, Boddington Res, 2nd October 2018 (Mike Alibone)

In addition to the size difference against the nominate race, ‘Tundra’ Ringed Plovers have darker upperparts and in October show no signs of the moult to first-winter which has normally already begun to take place in hiaticula. Additionally, the supercilium is less extensive, the legs are a dull, weak ochre and one other feature is the bill, which is smaller and ‘dinkier’ in Tundra birds. All these features are shown by these two birds at Boddington so it’s more than just tempting to call them ‘Tundra’ Ringed Plovers.

Grey Phalarope at Hollowell

Anticipation was running high among local birders when Storm Aileen made landfall in the UK on Tuesday, with the strong westerly blow continuing into the early part of Wednesday. The resultant winds, 70 mph in some areas, were already producing storm-driven seabirds along the western seaboard and the scene was set for discoveries further inland.

Wednesday, therefore, called for an early start and a reservoir tour was clearly in order, commencing at Pitsford dam. Unfortunately, Pitsford delivered nothing unusual – neither did Naseby, Welford, Sulby or Stanford.

I was beginning to run out of steam by the time I reached Hollowell and decided on a quick, long-distance overview of the northern and central parts of the reservoir from the lay-by on the A5119. And there it was, apparently the only wader there at the time, an animated speck, busily feeding along the shoreline of the Guilsborough Bay Point.

I quickly made my way to the point and, after putting the news out, started to watch and video it, keeping a safe distance so as not to disturb it. I needn’t have bothered. I was soon joined by Cathy Ryden and we were then dismayed to witness a crew of noisy young rowers cruising alarmingly close to the phalarope, at which point it was spooked and promptly vanished. Fortunately, Cathy relocated it later in the afternoon and it remained on site until at least mid-morning today.

First-winter Grey Phalarope, Hollowell Res, 13th September 2017 (Cathy Ryden)

First-winter Grey Phalarope, Hollowell Res, 13th September 2017 (Cathy Ryden)

First-winter Grey Phalarope, Hollowell Res, 15th September 2017 (Cathy Ryden)

First-winter Grey Phalarope, Hollowell Res, 15th September 2017 (Jonathan Cook)

First-winter Grey Phalarope, Hollowell Res, 15th September 2017 (Jonathan Cook)

First-winter Grey Phalarope, Hollowell Res, 15th September 2017 (Jonathan Cook)

Part of a national influx, this is the first Grey Phalarope in Northants since the relatively long-staying Pitsford individual in autumn 2014 and prior to that, there was one in 2011. There have been thirty-three previous records. As result of Aileen, many have been recorded across the UK during the past few days, although most have been seen at coastal locations.

Many thanks to Cathy Ryden and Jonathan Cook for supplying images,

Temminck’s Stint at Stanwick

The county’s first autumn Temminck’s Stint for sixteen years materialises in the early morning gloom of Stanwick’s Visitor Centre Lake.

Persistent patch-watching pays premiums – the proof appearing in the form of a nice adult Temminck’s Stint for Steve Fisher at Stanwick this morning. Present throughout the day on the Visitor Centre Lake, it performed well for all comers, allowing many to catch up with what is now a very scarce visitor to Northants.

Adult Temminck’s Stint, Stanwick GP, 21st August 2017 (Mike Alibone)

Lacking the fresh, brightly-fringed mantle, coverts and flight feathers, it’s a rather grey adult with a few dark-centred feathers of breeding plumage. The first Temminck’s Stint to be recorded in Northants occurred as recently as 1946, at Ecton Sewage Farm, where one was also present during winter 1968-1969 – an amazing record in itself.

Temminck’s Stint. Distribution of records by month over the last 30 years (1987-2016)

The vast majority appear in spring, however, with autumn occurrences being extremely unusual almost anywhere in the UK. May is the month in which to find one and Summer Leys LNR is the place to look, producing 48% of the May records over the past thirty years, followed by Stanwick GP, which produced 30%. The last in autumn, prior to this year, was a very approachable juvenile at Hollowell Reservoir, between 22nd September and 1st October 2001.

Juvenile Temminck’s Stint, Hollowell Res, September 2001 (Richard Chandler)

Conforming to the established pattern, there has already been one during spring this year, on 9th-10th May, at Pitsford Reservoir.

Baird’s Sandpiper at Stanford Reservoir

August 1st and Stanford’s waderfest continues unabated, producing Northamptonshire’s third-ever Baird’s Sandpiper this evening.

Hats off to Chris Hubbard for his sheer persistence in visiting Stanford Reservoir daily – often more than once – as his tenacity pays off handsomely with the discovery of the county’s third Baird’s Sandpiper this evening. This North American wader is very long-winged, with primary tips projecting well beyond the tail, giving the species a distinctively elongated appearance. This evening’s bird is an adult, aged by patchy upperparts with pale fringes worn off to some extent and lacking the uniformly fresh, scaly appearance of juveniles. It also has a fairly heavily streaked breast.

Unfortunately it hung around only just long enough for Chris to obtain the above phonescoped video and a small number of images before it flew off toward Blower’s Lodge Bay and was not relocated, despite several people searching.

Previous records were at Stanwick GP on 31st July 1994 and at Daventry CP on 29th September 1996.

First-summer Golden Plover

On 27th May, Bob Bullock found a European Golden Plover at the western end of Earls Barton Gravel Pits, where it remained until at least 29th May, when I managed to take the photos, below. We don’t usually see this species locally beyond mid-April so any solitary ‘Golden’ Plover occurring late in the spring is worth a second look – especially when it appears as dull and greyish as this one. Remember the first-summer American Golden Plover at Summer Leys from 13th to 17th May 2001?

When seen from a distance, in overcast conditions, the initial impression might have been that of Grey Plover – especially this spring, when we’ve had larger numbers than usual passing through. However, the bill is too small and neat, lacking Grey’s length and chunkiness.

In general, this bird’s structure does not immediately match that of either American or Pacific Golden Plover, both of which are of slimmer proportions and more elegant with longer legs. Closer examination also reveals closed wings only marginally extending beyond the tail, so ruling out the much more noticeably longer-winged American, and five primary tips extending beyond tertials – the latter reaching only halfway down the tail (too short for Pacific).

The lack of summer plumage this late in the year immediately suggests this is a first-summer and a closer examination confirms this. Upperparts are rather faded, there are few ‘golden’ spangles but many off-whitish ones and the rear flanks are barred (not so in full adult) and the tail feathers are barred off-white and brown, lacking adult’s yellowish chevron-like pattern,  as well as being rather worn.

In sunlight, this bird appeared noticeably warmer-toned and, in case there was every any doubt about the identification, it gave the typical Golden Plover “puwee” call and when it flew a short distance on a couple of occasions it revealed white axillaries and underwings, instead of smoky-grey …

‘Greenland’ Dunlin

A 3rd for Northants?

As part our exceptional wader movement this spring, there have been two reports of Greenland Dunlins – that’s the scarcer race, arctica, which turns up in much smaller numbers than the much more commonly occurring schinzii and alpina. One was with the mixed small wader flock at Stanford Reservoir on 17th May and the other, nicely illustrated in the photos by Bob Bullock here, was at Hollowell Reservoir six days later, on 23rd.

Features associated with this race, breeding in north-east Greenland and Svalbard, were described in Northamptonshire’s first, which was at Summer Leys on 9th May 2013. The excellent images by Bob illustrate the most of the key identification features but they are far from straightforward – particularly on a lone individual, which cannot easily be compared with other Dunlins.

In summary, arctica is slightly smaller than the other two races. It has a shorter bill and it appears generally greyer and less rusty/chestnut on head, mantle, scapulars and coverts. The black belly patch is smaller and usually less solid and the breast streaking is noticeably finer compared with that on schinzii and alpina.

 

 
Sounds easy but it isn’t. There is variation. There is also the added complication of first-summer Dunlin of one of the other races, which frequently has reduced black belly patch and may also appear greyer through not attaining full adult plumage. There is also first-summer arctica to consider … so a full suite of characters is the best way to nail one.

 

 

 
In spite of the fact that there was no size comparison made, the Hollowell bird ticks all the boxes, apart from one – and that’s the bill length, which looks longer in some images than in others. This may be as a result of sex, with females being marginally larger and having longer bills. Associating with other Dunlins, the Stanford bird on 17th was, according to the observer, Gary Pullan, short-billed, small and almost stint-like (as well as showing all the other correct features). Apart from tertials and coverts, which are very worn, the rest of the plumage is fresh and ‘classically’ arctica, with the mantle fringes cinnamon-yellow and not rusty-chestnut.

Richard Chandler has commented, “Yes, looks quite good for arctica, with the right cinnamon tones to the upper parts, and a smallish breast patch.  The relatively late date for Dunlin on migration is also supportive. Complications are the rather massive bill – but may be a female – and the worn plumage, especially tertials and wing coverts, which suggest a first-year bird and might be the reason for the rather pale plumage.  But I can’t see any obvious retained juv feathers as they are too worn to show the classic juv dark feather tips.  And would have been good to have had another bird for size comparison. But if I have to put a race to it arctica seems the most likely …”

Gary Pullan also stated, It does look quite good, it seems to be a 1st summer and probably a female given the length of the bill, so that doesn’t help to be absolutely sure in my humble and rather poorly-informed opinion. Saying that the new scaps etc are not particularly bright and the belly patch rather restricted (age related though?), both good points. Shame it was on its own, and I didn’t see it! The Stanford bird had a remarkably short bill, rather stint-like, I estimated it comparable in length to the distance from the bill base to just about the ear coverts, whereas this bird seems to have a bill the same length as the head itself. It was markedly small too and was probably a male.”

Many thanks to Richard Chandler and Gary Pullan for their comments.