Ferruginous Duck at Brockholes Quarry, Lancs, UK.
12th-17th September 2004. - by Bill Aspin.
Fig 1. This image nicely illustrates the long-billed appearance of the bird.
Sunday 12th September 2004 saw me once again routinely covering my local patch, Brockholes Quarry. Upon reaching no2 new working, a juvenile Black Tern showed well briefly before seemingly ‘vanishing’, so I moved to a higher vantage point to scan no3 new working in the hope that the Tern had moved onto this pit, but despite views of much of no3 from this position, there was no sign of the bird. However I decided I would still walk up to the pit and count any wildfowl present.
Upon arrival at no3, there was a small Aythya flock in the open water, and whilst counting them, I noticed what appeared to be a ‘dark-looking’ fem/imm Aythya Duck skulking along the outer margins of a small Bulrush bed on the opposite shoreline.
This initial view was at a range of c60m, into the light, and with the bird partially concealed within the outer margins of the Bulrushes. Despite this, what I could make of the head-shape was clearly not suggestive of Tufted Duck, so I switched position to get the bright sunlight behind me. The result of this was that the Aythya swam further out into the open water.
Fig 2. This image is the best I obtained of what I would call the 'classic' Ferruginous headshape. More often than not, the bird showed a rounder headshape when actively feeding.
With the light now behind me, and the bird in open water, I trained my scope upon it and in the bright sunshine was able to note a headshape that had a rather high sloping forehead with a peak slightly towards the rear crown, obviously pale buff lores, brown/chestnut overall tones to the plumage and an extensive, seemingly at the time (in very bright sunshine), clean white under-tail covert area. Upon these initial better views, I muttered to myself “Why is this not a Ferruginous Duck?” – However, I had not even seen the bill pattern well or the open wing!! But at this early stage, my gut feeling was that the bird was either a pure Ferruginous or a convincing Aythya hybrid.
Fig 3. This image, taken through long grass, shows the 'long-billed' appearance, pale buff loral area, paler area on the throat, a contrasting 'capped' appearance, obviously darker than the rest of the head.
So, over the next hour I sat down and attempted to obtain views and video footage of the bird with particular emphasis on the bill pattern and wing-stripe. During this time, the bird performed a wing-flap only once, showing a broad wing-bar with pure white secondaries, the white extending onto some of the outer primaries. With the exception of a dark nail, the rest of the bill appeared dark grey. I was also struck by the ‘long-billed’ appearance of the bird when compared to the Tufted Ducks also present on the same pit.
Fig 4. The wing-bar was broad, with white extending onto some of the outer primaries.
Fig 5. This record image shows a dark nail on an otherwise grey bill. In many views I found the nail was difficult to discern from the rest of the bill colouration. In only a single view did I note a very faint pale sub-terminal line behind the nail.
Armed with the features I had noted, but with no experience of a Ferruginous Duck of this age/sex in at least the past decade, I returned home to research on the internet / available literature.
After a couple of hours I came to the conclusion that I could not find anything obviously hybrid about the quarry bird, but despite this, I decided to post some images with comments on the website inviting feedback from others, just in case I was somehow missing a hybrid feature. In the meantime, I returned to the quarry to further observe the bird.
It was now early evening and the weather had changed dramatically from the afternoon. It was cloudy, dull and raining steadily. In this totally different light, it was now obvious that the undertail coverts were not completely clean white, but had 'dirty' brown feathering mixed within. It was in this light that I noticed, in a single view only, a very faint pale sub-terminal line behind the nail.
Fig 6. The 'dirty' brown feathering in the white undertail coverts can be clearly seen in this image.
Fig 7. The belly although showing a well defined 'rim' was predominantly mottled brown. What can be seen of the undertail coverts is bleached out by the strong light.
Fig 8. The paler loral area + throat and chestnut plumage tones can be made out in this image. As again, can the long-billed appearance.
By this time I still could not turn the bird into anything other than a pure Ferruginous Duck and feedback from other experienced birders during the evening was positive.
The bird remained on no3 new working for the vast majority of its stay. Occasionally it would fly the short distance onto the adjacent no2 & no4 new workings when alarmed. It was reasonably well twitched during the week and was last noted as still present at c16.00hrs on Friday 17th Sept.
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The age of the bird.
Confident with the identification in my own mind, the next step was to age the bird. At the time I was uncertain, but I am now of the opinion that the bird is a juvenile, mainly for the following reasons:
1) A mottled brown belly.
2) Brown feathering in the white undertail coverts.
3) A very indistinct pale subterminal line behind the nail (only seen once by myself. I am not aware of anybody else seeing this feature?). Otherwise the bill appeared dark grey.
A couple of questions I have asked myself in the case of the bird possibly being an ad female in eclipse were:
1) Would the undertail covert area on an ad female in eclipse remain clean white? (see Fig 6). Reference in both 'Collins Bird Guide' and 'Wildfowl' suggest it would remain clean white.
2) Would the colour of the belly be as brown on an ad female in eclipse, as shown by this bird or would the belly remain largely clean white? (See Fig 7). I would say it would remain (largely?) white, given that belly colour is a feature used on a range of Duck species for ageing juveniles from adults.
3) Would the belly of a juvenile show such a distinct 'rim' or would it be less demarcated as shown by this bird? (see Fig 7). Evidently so, content in my own mind that this bird is a juvenile.
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Behavior.
A very interesting aspect of the bird was it's apparent textbook behavior. To quote from Wildfowl (Madge & Burn 1988): Ferruginous Ducks have 'Generally rather solitary habits and preference for feeding close to or amongst emergent vegetation making it easy to overlook'.
For me this sums up the behavior of the Brockholes bird to a tee. It seemed rather loathed for the majority of the time to feed out in the open water or associate with the small Tufted & Pochard flock, preferring instead to feed alone amongst the narrow Bulrush beds, c3m from the shoreline.
Only when approached too closely would it swim out, sometimes joining the other Aythya's present, but would soon swim to the shoreline of the pit to feed and would almost always inevitably fly back to the NW corner of no3 to feed in it's favoured area alone. Indeed, when in it's favoured feeding area, the bird was not visible to would-be observers scanning for the bird from 98% of the perimeter of the pit and even when observing the bird it could lost for periods amongst the beds as it fed totally unobstrusively.
Description.
Size / Jizz: Slightly smaller than Tufted Duck. The most obvious feature of the ‘jizz’ aspect of the bird was for me the head-shape and the length of the bill. The bill was long in relation to the head. The head immediately above the bill base of the upper mandible was steep, then sloped and peaked at the centre of the crown. To the rear of the peak, the nape fell away rather sharply, yet maintaining a curved shape. When actively feeding, the bird appeared rounder-headed.
Bare parts:
Bill: Dark grey with a black nail. In many views the contrast between the nail and the rest of the bill was hard to discern.
Head: The feathering on the loral area was pale buff/ginger. To a lesser extent, but still noticeable, this was also present around the ear covert area and was separated from the loral area by darker feathering below the eye/on the cheeks. The crown was a dark, rich warm, brown, giving the bird a distinctly ‘capped’ appearance, and contrasted with much of the rest of the head.
Throat: The throat was pale on the front. The sides were a richer, darker brown.
Upperparts: The entire upperparts were
dark chestnut brown.
Flanks: A rich, warm, chestnut brown.
Breast: Chestnut brown.
Underparts: The belly was entirely mottled
brown, yet with an obvious ‘rim’ bordering the flanks.
Tail: Dark chestnut brown, the same colour
as the upper-parts.
Under-tail coverts: Extensive, clear-cut,
white, but with obviously browner feathering within.
Open-wing (upper): On the forewing, all
wing-coverts were a rich dark brown. The secondaries consisted of a broad and
clean white speculum and an obvious dark trailing edge. The white from the
secondaries extended well into the primaries, gradually fading into grey on the
outer primaries. The dark trailing edge on the secondaries continued along the
full trailing edge of the primaries.
Axillaries: White.
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The record has been accepted by the BBRC, constituting approx the 14th Lancashire record.
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The Martin Mere bird of mid-October 2002. - a brief discussion and comparison of this bird and the Brockholes bird of mid-Sept 2004.
Further afield but of relevance to the Brockholes bird, my friend Tony Disley found this female Ferruginous Duck at Martin Mere on 13th October 2002.
Tony still has reservations regarding the ageing of the bird as a first winter. After looking at the videograbs below that Tony obtained at the time he found it (a month later in that particular year than the Brockholes bird occurred) and after comparing it to the appearance of the BQ individual, I too share his reservations.
These video-grabs taken just a month later in the respective year than the images of the Brockholes individual show a bird with an essentially clean white belly, with just a few brown flecks and also a more defined paler subterminal area to the bill. Surely a bird of the year would not show such 'older' features by mid-October. Are the shape/moult of the tail feathers a clincher to the age?
If anybody has any comments regarding both the ageing of the BQ & MMWWT birds, whether in agreement or not, I would be interested in hearing them to perhaps further my knowledge of the species. Please email Bill Aspin. - Thanks.
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