Siberian Chiffchaff …ing

Grey is the new sandy!

By Martin G. and Anthony McGeehan

What do you think? They invite tireless fascination don’t they? With an estimated 65 in the U.K in January 2013 (per Birding Word) often in urban sites including birders gardens (see below), Siberian Chiffchaffs are both available and accessible. Appreciating their remarkable journey while learning the vagaries of their appearance are part of their appeal.

Inishbofin. December 2012 – January 2013

Found by Dermot Breen before Christmas, Anthony McGeehan watched this individual over 3 days on the island off Ireland’s west coast and (below) explores the issues of ‘plumage morphing’.

Siberian-Chiffchaff,-green- AMcG

Siberian-Chiffchaff,-inside AMcG(above) Siberian Chiffchaff, Inishbofin, Ireland. January 2013 by Anthony McGeehan. The same bird in both photographs.

    “Light exerts an influence on vision and plumage tints vary depending upon the light. Tilt a Mallard wing and the speculum switches from deep purple to blue; watch a drake Tufted Duck twist its head from side-to-side and the lustre changes from green to blue. Few get excited about such variation. In other situations the ambient light of surroundings exerts influence. Lapwing breeding plumage comes alive when sunlit but can appear close to monotone in total overcast. Hence angle of light, background ‘lighting context’ and tilt of plumage can, separately or collectively, combine.

   Sometimes the cocktail has an effect on the assessment of field marks. In Ireland, where some Coal Tits are more yellowish-cheeked than others, the strength of the yellowishness is emphasised when the bird faces obliquely away. In a flash – or burst of images from a DSLR – the rear cheek goes from cream to buttery-yellow. Quite what is going on is beyond my ability to explain but factors such as angle of light and the ‘nap’ of plumage are probably key elements in the process.

   On several species, loral patterns vary between dark and pale. Once again, angles are important and are complicated by the fact that loral plumage more-or-less runs in a different direction to that surrounding it and that this part of the head is slightly concave.

   More straightforward to comprehend is the ‘bounce’ of colour derived from surrounding vegetation. A Blyth’s Reed Warbler will look brownish-olive across its upperparts in sunshine but the olive component disappears in dull light. Depending on the angle of the bird’s torso, its folded wings will glint bronze in some positions but not others. Not surprisingly, such subtle cameleon nuances can become important when identification hinges on a whether a specific colour is detected.

   The truth is, plumage contours, light and background vegetation are all at work. For this reason Siberian Chiffchaffs can exude greyness or brownness. Background light is the main determinant in their ‘global’ colour but, at a ‘micro’ scale, a switch in body alignment will, by itself, oomph up the green cast from remiges that, a moment before, looked uniform with overall brownish (or greyish!) wings. There is nothing unusual in the light-registering ability of Siberian Chiffchaff plumage. Grey is the new sandy!”   

Anthony McGeehan

Chiffchaffing in Poole, Dorset. January 2013

Coined by Tormod A. somewhere between Oxford and Kent (via Dorset) during the ‘Pushing the Boundaries Tour, ‘Chiffchaffing’ seemed to suitably described the engrossed observations of a group of tiny but super hardy little leaf warblers. With 15 Common Chiffchaffs having been ringed there this winter already, the drain (like a canal) at the back of PC World in Poole, Dorset holds plenty. Amoung them are 3 ‘others’. Marcus Lawson was our guide having found a veritable Siberian Chiffchaff on his Footit challenge and a second (intriguingly ringed) bird which also might pass muster as a ‘tristis’. We came across a new tristis and saw both of the original birds alongside c 8 Common Chiffchaffs:

Sib Chiff first bird 2013-02-14_062803(above) Siberian Chiffchaff, Poole, Dorset, January 2013 by Martin Garner. This is Bird One, found by Marcus on his Footit challenge.

tristis type ringed bird 2013-02-14_062403

tristis type ringed bird 2013 strip(above 4 photos) Possible Siberian Chiffchaff, Poole, Dorset, January 2013 by Martin Garner. This, Bird Two is the ringed bird. With extra olive above and yellow below its not straightforward though watching it live it certainly gave off a Siberian air’; an individual worthy of further careful study and recording.

Siberian Chiffchaff new bird 2013-02-14_061611(above) Siberian Chiffchaff, Poole, Dorset, January 2013 by Martin Garner. This is Bird Three, found on the Pushing the Boundaries Tour. It exuded Siberian-ness. It was also heard to give the classic ‘peep’ call.

Sibe Chiff BS2

Siberian Chiff Brett Spencer(above) Siberian Chiffchaff, Dorset, 5th February 2013 by Brett Spencer. Surely a delightful garden find for Brett. He captured very effectively the colour morphing from brown to grey.

Me? I can’t get enough of them.

So……what about your experiences of Siberian and other Chiffchaffs?

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About Martin Garner

I am a Free Spirit
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9 Responses to Siberian Chiffchaff …ing

  1. Laurie Allan says:

    More like ‘Pishing’ the Boundaries…………….

    Laurie –

  2. Harry Hussey says:

    Even as far west as Ireland, where some eastern taxa annual in Britain are already at a premium even at coastal sites, there have been more than a few wintering Siberian Chiffchaffs seen away from prime passerine spots. This winter alone, subject to acceptance, there have been at least eight that I can think of off the top of my head that were inland or in urban areas, and the first certain one that I saw myself, back in 2007, was a bird picked up on song about 30 minutes’ walk from my house.

  3. Sacha Barbato says:

    Great article. I submitted a description (for Norfolk committee) for a Siberian Chiffchaff that I found on Blakeney Point a few years ago. In the description I mentioned the change in tones from when I first found it (in dull light) and how different it looked later in day in bright sunshine. It really does make a difference and shows how relying on just one or two photos can be misleading. We do not seem to get many wintering here in Norfolk so am looking forward to finding and seeing some migrant Sibe Chiffs in more detail soon!

  4. Tim Allwood says:

    The issue for me is where the line is being drawn. What is the acceptable phenotype for birds being labelled ‘tristis’? How much extra yellow before it’s too much yellow? How much olive tone before it’s too much and does the bird have to exclusively ‘peep’? Can a disyllabic/slightly inflected call given now and again still fit tristis? How much peeping is necessary? How much of a swee-ooo is acceptable. What if it also goes ‘hweet’ on occasion? Can we expect some new guidelines soon for records to be judged against? Will they be accepted by county committees on a balance of probability? Should that happen?

    A bird I saw at Hickling in January that was reported as tristis had a distinct olive tone, a fair amount of yellow below and called ‘peep’ for two hours before deciding to start ‘swee-ooo’ing and even gave one ‘hweet’? Baffling.

    I think we need to know much more about the phenotypes, genotypes, calls and songs of birds across the range of collybita, abietinus and tristis before we can be reasonably confident of what we are looking at. A typically brown-and-buff bird with some rufous tones and no extra olive or yellow, that goes around peeping all day is simple. As we move westwards, however, what’s happening with chiffchaffs seems to be rather murky. We don’t even seem to know what abietinus really is now. Yes, these birds are fascinating but do we really know what they are at present?

    • Alan Dean says:

      Tim’s comments relate to the broader issue of plumage limits in tristis, rather than ‘colour morphing’, but are well said. The birds with brown and buff hues and a rusty tinge, with a consistent ‘peep’ call (Tim’s ‘easy’ birds) can be assigned with confidence to tristis. The ‘others’ are best left unassigned. This has been the position consistently advocated by Lars Svensson and myself ever since the 2005 BB paper, where we listed a number of possible sources of such enigmatic individuals. If a Chiffchaff gave more ‘hweet’ calls than ‘peep’ calls, does that make it tristis because “the peep call is diagnostic”? What if the plumage were also anomalous? I don’t know – but I wouldn’t log it as an unequivocal tristis, I’d leave it unassigned. Of course, such individuals should be thoroughly documented and kept on file, for future reference and potentially identification to form as knowledge increases. However, their true identity and lineage poses questions to which we don’t yet have the answers.

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  6. Alan Dean says:

    In the photographs illustrating what is being dubbed ‘plumage morphing’, it can be seen that the background is ‘morphing’ too. Where the Chiffchaffs look paler and greyer, the colour temperature of the entire image is clearly colder. While variations in light conditions will not only affect plumage, the published photographs are also being affected by the camera’s white balance. One has only to look at the overall appearance of some of the images to see that they do not have a natural colour appearance or ‘colour balance’. Some are clearly ‘overly cold’, others ‘overly warm’. In the field, when there are strong colour distortions, the human eye (and brain) will soon become aware of it.
    Anthony McGeehan’s examples of colour shifts in specula, the head of Tufted Duck and Lapwing’s plumage are all examples of iridescence. This arises from structural features of the feathers which produce optical interference and this is inherently subject to the angle of the light. This structural colour effect is quite different from colour arising from feather pigmentation. The appearance of pigment-derived colours will certainly be affected by light conditions but to a markedly less-striking degree.
    When a bird with dark legs e.g. Rock Pipit, is strongly back-lit, its legs can take on a pinkish appearance, imparted by the blood-vessels. Shall we call this ‘bare part morphing’? Fair enough. But we do not conclude that it is impossible to determine that, in fact, a Rock Pipit has dark legs. We make a correct assessment based upon adequately prolonged observation and an appreciation of how light conditions can temporarily deceive.
    Because Siberian Chiffchaffs with brown and buff hues can at times (but not persistently) appear paler and greyer, this does not mean that their full plumage hues cannot be assessed with adequate observations. Nor does it mean (as some people seem almost to suggest) that truly pale and grey Chiffchaffs do not really exist – ‘it’s just plumage morphing’. This is a complete non-sequitur. Let’s be aware of – but not exaggerate – the problems. Let’s keep a sense of proportion.
    Alan Dean

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