Plumage Morphing

by Martin G.

Here’s the first of a 2 parter on Siberian Chiffchaff ID. Part one is on plumage. Part two is on calls. Trying to make sense of my own experiences, even if limited, has helped forge much of my current thinking. A Rough Guide with summarising bullet points appears at the end.

Siberian Chiffchaffs are of course fascinating. First off they have Siberian in the name, and they really do mostly come from a large area north of Kazakhstan and even further east. They can turn up in winter months in random places (a good foot it target), often associated with water – notably sewage works (of all places). Undeniably enigmatic with (even in 2013), lively debate surrounds the precise nature of calls, their plumage and their relationship with other kinds of Chiffchaff.*
Morphing Colours

Foula, October 2007

On the issue of plumage, mid October 2007 on Foula, Shetland proved educational. I had previously seen several Siberian Chiffchaff types in the past, including notably grey birds. Residing alone in the Ham Valley for week (Foula pioneers Tim Drew and Mark Wilkinson resided at Ristie and we worked the south together each day) I scored Dusky Warbler, Yellow-browed Warbler, 2 Olive-backed Pipits and a Common Rosefinch all in the same ‘patch’. I also saw at least 2 Siberian Chiffchaff types that were easily studied. As with many on Shetland no calls were heard. The birds fed only c200 metres apart, one in a hedge the other on a grassy slope. They looked quite different from each other.
N.B. All the photos below taken by me are ‘straight from the camera’. Only cropped/resized and sometimes slightly sharpened. Unless specifically stated I have not tweaked their levels.

1 b and b foulaSiberian Chiffchaff, Foula, Oct. 2007. Bird number one. Found in the post office hedge. Though it never called, it ticked all my boxes. Very brown and buff, weak olive confined to wings, rump and tail on field views, thick buffy supercilium. ‘Swarthy’. Curiously when photos are blown up some olive is just visible on the scapulars which I never recorded in the field.

tristis type Foula Oct 2007Siberian Chiffchaff, Foula, October 2007. Bird number two. I no longer have the original photo of this shot, so I guess I may have tweaked it. This bird fed openly on a grassy slope. Here looking whiter beneath than bird one, but otherwise still pretty buff and brown looking I think.

However what was striking about watching it in the field was its ability to ‘morph’ into a Bonelli’s Warbler-like plumage. It could look at least closer to ‘grey and white’ than ‘brown and buff’ with bright yellow-green fringes to the wing and tail feathers.

4 Sib Chiff Foula Oct 2007 130

bonellis chiff foulaAbove 3 photos: Siberian Chiffchaff, Foula, October 2007. Bird number two. Apart from cropping and slight sharpening, all photos as ‘from camera’. Looking quite different from bird number one; in the moment I (incorrectly) labelled it was one of those ‘grey and white Chiffchaffs’ of uncertain identity.

10 Sib Chiff Foula Oct 2007 130Above: Siberian Chiffchaff, Foula, October 2007. Same bird, number two, now looking to my eyes pretty good for my typical search image Sib. Chiff. Motion blur on the wings and where have the bright yellow-green fringes gone?

3 Sib Chiff Foula Oct 2007 130Above: Siberian Chiffchaff, Foula, October 2007. Same bird, number two. Back to somewhat more brown and buff. Which photos represent the real bird?

So was this a grey and white or brown and buff Siberian Chiffchaff? or both?! Certainly some birds are even greyer than this. Importantly experience has taught me that the subtle pastel plumage tones really do ‘morph’ in Siberian Chiffchaffs. I can’t exactly explain how, but they do. Browner birds can look greyer and even the most grey and white birds, in fresh plumage can hint brown and buff. No single photo (or even declaration of field appearance) can be definitive. Here’s another example.
Doncaster, December 2009

Chiffchaff tristis 11 December 2009

tristis 10 December 2009 239

tristis 11 December 2009 Lakeside

10 December 2009 193Above 4 photos. All of the same Siberian Chiffchaff, Lakeside, Doncaster, December 2009. With plumage tones of brown above and buff and white below, thick buff supercilium, pale wing bar and tobacco tinged ear coverts it ticked the plumage boxes. However it could morph colours depending on light and angle of viewing, looking either greyer-brown or warmer dun brown above and in low evening (winter) sunshine could even glow yellow in parts (when there was no yellow in reality).

Jerusalem, November 2012

Chiffchaff nov 19th 2012 JBO 3

Siberian Chiffchaff. Jerusalem Bird Observatory, 19th Nov 2012. More photos of this one here. A real brown job, still with nice rusty ear coverts and a variant tristis call (more on that in next post).

Oxfordshire, January 2012

lew 3

lew 2

Sib Chiffchaff lew oxford

Sib Chiff Oxford lewAbove 4 photos . Siberian Chiffchaff, Streatley Treatment Works, Berkshire, Feb 2012 by Ian Lewington. Same bird in all 4 photos. Ian described it as “appearance metamorphosed greatly depending on the light.” In the upper photo the bird’s ‘saddle’ is undeniably grey with faint olive strips. The head pattern varies from very weak looking for tristis in top photo to obviously tristis in 3rd photo.

The bird went ‘bananas’ to recording of tristis song, coming in very close, manically hopping from branch to branch and wing quivering (lowest photo). It did not respond to nominate collybita song. Meanwhile several nominate collybita present at the same site responded to collybita song but not to tristis song. This bird was one of two that gave a “perfect tristis call”.

Burjatia, Eastern Siberia, September 2009

compare 2DSC02532

compare uppersbrownAbove 4 photos. Siberian Chiffchaff, Burjatia, East Siberia, 7th Sept. 2009 by Mats Waern. This set of photos is all of the same individual tristis, photographed east of Lake Baikal, at or beyond eastern limit of tristis range. The photos are all of the very same individual.

“The difference between the bird looking essentially brown above or essentially grey above is a minute apart, in different sun/cloud conditions. This is not primarily a photographic problem (both photos most likely give a representative image of the bird at each respective moment) but instead a problem for ALL kinds of observations of Chiffchaffs, including when handling them during ringing – they do look different in different light. This fact makes it very difficult (at least away from standardized light conditions) to discern discreet plumage types with any certainty, including ‘grey-and-white’ ones” (Magnus Hellström).

Northumberland, October 2009

sibe chiffSiberian Chiffchaff. A ‘classic’ tristis. Low Newton by the Sea, Northumberland, Oct. 2009, Gary Woodburn

Gary Woodburn’s patch is Low Newton by the Sea, Northumberland which seems to be a fairly regular spot for Siberian Chiffchaffs over several years. He writes about 3 birds seen and trapped in October 2009: 2 brown and buff, 1 more grey (and olive) and white. All uttered the same ‘peep’ call.
“In October 2009 I had three birds in the space of 10 days all calling with only a “peep” call and all eventually trapped and ringed.
The first bird from 14th – 17th Oct was not a ‘classic’ tristis looker, it wasn’t far off but was a little greyer/paler overall than most and at close range (in the hand) more olive tones were noticeable. However, in the field it looked more peachy faced like tristis and never deviated from the “peep” call.
The other 2 birds came a few days later and were more classic brown/buff birds. These were both trapped on the same day and both seemed to conform to what we currently see as classic brown/buff/white tristis.”

sibe chiff3Siberian Chiffchaff. A ‘classic’ brown and buff tristis. Low Newton by the Sea, Northumberland, Oct. 2009, Gary Woodburn

chiff3Siberian Chiffchaff. Gary’s first bird, described as not ‘classic’ tristis. Low Newton by the Sea, Northumberland, 14th – 17th Oct. 2009, Gary Woodburn. Clearly grey (not brown) above with subtle olive strips, the head pattern nevertheless looks pretty typical for tristis. This bird looks,to my eyes, very similar (almost identical) to that cited in Dean and Svensson (2005) from Upton-on-Severn, Worcester, under case studies of ‘grey and white tristis-like Chiffchaffs’ (plates 241-2).

chiff6Siberian Chiffchaff. Gary’s first bird described as not ‘classic’ tristis. Low Newton by the Sea, Northumberland, Oct. 2009, Gary Woodburn.

Dutch Birding, December 2012

2 tristis 7-11-2010 Wassenaar Vincent van der SpekSiberian Chiffchaff- at least it’s mother was… by Vincent van der Spek. The mtDNA of this bird was tristis (mtDNA is inherited through the female line). I think I would struggle with this in the field and definitely want to hear it call! It’s certainly not a nominate collybita and reminds me of this bird in Shetland in 2012. Almost silvery -grey above with wisps of yellow-olive. Clean white looking supercilium and underparts, interrupted by bright yellow supercilium spot and what looks like a lemon wash in vent. This bird is the most extreme looking in this ground breaking paper just published. The paper covers mtDNA research on 41 Chiffchaffs trapped in the Netherlands in autumns of 2009-11. Most of these 41 were birds identified in the hand as not typical nominate collybita– some being identified as tristis and others as abietinus. I think most of the rest of the birds presented in the paper actually do look more or less like Siberian Chiffchaffs, including others identified by ringers as abietinus.

Critically in the paper all birds identified as abietinus were found to be tristis based on mtDNA (as well as all the obvious tristis). The limitation of the research is that it consisted of “birds which did not look like typical nominate collybita or from very large birds”. This, in turn, means that birds looking similar to collybita were deliberately excluded from the sampling. In fact, many abietinus in fresh plumage are so similar to collybita, that it seems likely had there been any, the ringers in the Dutch study would have overlooked them as collybita.

A photo (by Luc Knijnsbergof) of a different looking bird in the paper which is quiet olive above but with veritable tristis head pattern can be found here. It also had mtDNA of tristis. The first British Siberian Chiffchaff confirmed by DNA is here.

a tristis 7-11-2010 Wassenaar Vincent van der SpekVincent (Tengmalm’s) van der Spek, one of the authors comments:
“Yes, many questions remain, so we will continue this on a larger scale and with a-select sampling instead of collecting material of suspicious birds, mainly to get a better understanding of abietinus. An obvious conclusions we can draw about abietinus is that Dutch ringers have been using the wrong criteria for identification.”
Concluding tristis thoughts:

My observations to date lead me to a broad type/ search image of Siberian Chiffchaff. They vary broadly from buff /brown to grey/white with lots of subtle variation (brown-grey, grey-brown, olive-grey, olive-brown) from one extreme to the other. Any single bird can ‘morph’ it’s appearance in the field, even to raising the question of what constitutes correct perception of tones in the field (as well as in photographs ). Greyer birds often have a very similar head pattern to buff/brown birds and have the same ‘tristis‘ call. Crudely, they look like the same kind of beast.

Grey and white Chiffchaffs.

I haven’t personally seen the discreet plumage type called the ‘grey and white Chiffchaff’ described in Dean and Svensson (2005). i.e. birds which ‘lack entirely the characteristic brown and buff hues and rusty tinge of tristis’ (Alan Dean pers comms). The term ‘grey and white Chiffchaff’ has however been loosely applied to greyer looking tristis and probably held back many straightforward identifications. Of 57 individual claims of tristis submitted to the BBRC ‘tristis panel’ (see Dean 2010) there were no ‘grey and white Chiffchaffs’ as strictly applied. Whatever they are, they seem to be rare in Britain.

Hybridisation has been reported on at least a limited scale between abietinus and tristis. As such there are likely to be some birds which suggest hybrid/ intergrade or are at least unidentifiable ‘grey and white Chiffchaffs’. One such may be here. The frequency of these ‘grey and white unidentifiables’ (which do seem rare) is better established as we continue into the future (better photography and recording of all calls/song), rather than endlessly pouring over records that lack critical data. So rightly or wrongly I want plumage and sounds! If a bird essentially looks like my search image for Siberian Chiffchaff (don’t think something looking like nominate collybita and calling/singing like tristis is going to get my quick vote) and at least includes Siberian Chiffchaff ‘peep’ calls in its repertoire (including my growing understanding of ‘normal variation’), then I am calling it a Siberian Chiffchaff.
The abietinus issue

2 independent studies failed to find the presence of abietinus Chiffchaff DNA amoung Chiffchaffs in late autumn and winter in the U.K. and the Netherlands. It is clear that our understanding of both the appearance of abietinus Chiffchaffs, and its occurrence in Western Europe is flawed. We are back at square one with many new questions about this taxon. The logical extension of the Dutch Birding paper is that any Chiffchaffs befitting the title ‘non-collybita’ and wintering in Britain are more likely to be tristis than abietinus.

JBO Chiff 19 nov

JBO chiff 3

JBO chiff 4Above 3 photos: Chiffchaffs at Jerusalem Bird Observatory, Israel, 19th Nov. 2012. I wonder if these are abietinus on migration? With a grey undercoat to head and upperparts, overlain with yellow-olive strips, broad white supercilium and whitish underparts punctuated with clean bright yellows. Photos of abietinus, some of which certainly fit the appellation of ‘grey and white Chiffchaff’ can be found here.

The BIG QUESTION thrown up by the Dutch Birding paper (and other UK based research see here) is that our understanding of the occurrence of abietinus in Britain is all wrong. It may be a genuinely rare bird. There are some ringing recoveries of birds from e.g. Sweden in Britain, however most of the Finnish population heads southeast on migration (BWP). Has the status changed? Perhaps most of the population of abietinus now heads southeast or some occur very briefly earlier in the autumn?

One analogy might be to see abietinus Chiffchaffs as the ‘Baltic Gull of the warbler world’. Baltic Gull (nominate Lesser Black-backed Gull), breeding in Scandinavia once recorded all over Britain, is now understood to be a very rare bird whose populations largely heads in the wrong direction to regularly reach Britain. In the interim as more research is undertaken, it would not be wise to claim abietinus as late autumn/ winter visitor in Britain. The choice, the Dutch paper would suggest, is between collybita and tristis.

For completion I was intrigued as to the true appearance of the Common Chiffchaffs of the Middle East- particularly as they call very like tristis. But it seems they don’t look like ’em:

Phylloscopus collybita brevirostris 2 Osmaniye Turkey June 2008 © José Luis Copete

Phylloscopus collybita brevirostris Osmaniye Turkey June 2008 © José Luis CopeteAbove 2: Common Chiffchaff ssp. brevirostris, Osmaniye, S. Turkey, June 2008, © José Luis Copete The plumage, structure and biometrics are very similar to collybita (José Luis Copete pers comms)

Phylloscopus collybita C macho (adulto) Campelles Girona Spanish Pyrenees June 2009 DSCN3770 © JL CopeteAbove: To compare with brevirostris this is a nominate collybita Common Chiffchaff, from same latitude and same time of year as the brevirostris photos further up. Campelles Girona, Spanish Pyrenees, June 2009 © JL Copete
Caucasian/ Mountain Chiffchaff

And just to complete the set. Variously considered to be either 2 subspecies lorenzii and sindianus or 2 full species separated as Caucasian Chiffchaff, P. lorenzii and Mountain Chiffchaff, P. sindianus.

P. s. sindianus: Pamir-Altay mountains of central Russia/CIS east to the northwest
P. s. lorenzii: Caucasus: mountains of northeast Turkey and northwest Iran, breeding
above 1800 m a.s.l.

DSCN4334 jlcCaucasian/Mountain Chiffchaff ssp lorenzii Gelinkaya, Turkey, June. © José Luis Copete.

Caucasian/Mountain Chiffchaffs also give a monosyllabic very tristis-like ‘peep’ call. As Chiffers go distinctive looking beasts with distinct warm browner plumage above; mahagony on the crown with often short looking white supercilium arching over the eye. I was under the impression that the fringes to flight feathers were supposed to be white. José Luis Copete and Lars Svensson put me right. Fringes to remiges and rectrices can appear white, be pale brown and sometimes with yellowish or olive tinge. See below:

Luì del Caucaso; Caucasian Chiffchaff; Phylloscopus lorenziiCaucasian/Mountain Chiffchaff ssp lorenzii, Gelinkaya, Erzurum, Black Sea Coastline, Turkey 24th May 2011 © Daniele Occhiato.

lorenzii – 3051 – ed 01Caucasian/Mountain Chiffchaff ssp lorenzii, © Lars Svensson. Some olive components seem evident on the wings of this lorenzii– even maybe dash of yellow on the supercilium above the eye. Variations!
A rough guide to plumage issues:

tristis varies from brown to grey looking above with/without olive bits and extra little bits of yellow can be present. Head plumage often distinctive.
Same bird can ‘morph’ appearing both brown and grey (to do with light ‘n stuff).
Brown/buff hues are limited to season. Many mid-winter and spring birds become greyer and can lose buffs and browns.
abietinus – need to start from scratch on its appearance and occurrence. Likely a rarity in Britain?
Choice for most autumn/winter Chiffchaffs is either collybita or tristis.
The term ‘grey and white Chiffchaff’ has been confusingly used. Originally applied to autumn birds completely lacking buff and brown tones (these normally being present to some degree on the head patterns of most tristis). The particular ‘grey and white Chiffchaff’ plumage intended by Dean and Svensson (2005) seems to be rare in Britain n.b. identifiable Siberian Chiffchaffs are much more common.
There are still occasional birds which defy easy identification due to plumage/sound peculiarities. These are worthy of the most careful study with the aim of collecting as much data on them as possible. They may be best left unidentified.
There is still stuff to be discovered particularly about the precise extent of any hybridisation between tristis/abietinus and the degree of introgression of abietinus characters into the western tristis population. We are all learning!

* Key ID papers
On plumage: the writings (and correspondence) especially of/with Alan Dean, Lars Svensson, José Luis Copete, Magnus Robb, Arnoud van den Berg and The Sound Approach, Magnus Hellström, Mike Langman, Ian Lewington, Daniele Occhiato, Gary Woodburn, Vincent van der Spek, Mats Waern, Lance Degnan, and Mick Cunningham have been illuminating, controversial and ground breaking. Without them (all!) I would be struggling a lot more and inspired a lot less.
van den Berg, A B & The Sound Approach 2009. Calls, identification and taxonomy of Siberian Chiffchaff: an analysis. Dutch Birding 31: 79-85.
Constantine, M & The Sound Approach 2006. The Sound Approach to Birding. Poole.
Constantine, M, Hopper, N & The Sound Approach 2012. Catching the Bug. Poole.
Cramp, S (editor) 1992. The birds of the Western Palearctic 6. Oxford.
Dean, A R & Svensson, L 2005. ‘Siberian Chiffchaff’ re­visited. Br Birds 98: 396-410.
Dean, A R, Bradshaw, C, Martin, J, Stoddart, A & Walbridge, G 2010. The status in Britain of ‘Siberian Chiffchaff’. Br Birds 103: 320-338.
Ebels, E B 2009. Siberische Tjiftjaffen in Nederland: voorkomen en determinatie. Dutch Birding 31: 86-100.
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This entry was posted in 18) Warblers, Crests, Wrens, Shetland on January 1, 2013 by Martin Garner.
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20 thoughts on “Siberian Chiffchaff and Common Chiffchaff: Part 1”

Ben Porter
January 1, 2013 at 6:32 pm

Interesting! Would be interested to see thoughts on the Chiffchaffs here: . Since then there have been about six birds (on Bardsey Island) which are now looking more likely to have been tristis.
Reply ↓
Brian S
January 2, 2013 at 10:10 am

Hi Martin, a quick (but may be rambling) reply to your post. In my opinion what the above highlights, almost more than anything, is the variation in colour cast (caused by light and photographic effect – as Magnus mentions), but also exposure and I am sure individual perceptions of colour. I like to think that as an artist, mixing colours all the time, and with a degree in Photography (with plenty of colour printing and image manipulation) that my idea of colour is accurate – however, it too may be biased. Then there is the set up of your computer screen – I have set my hi-res Mac screen up using a colour card so it is as accurate as I can get it.

If I go through your sets in order: set 1 (Foula) to me look very yellow and the colours (such as ‘grey’ or ‘olive’) you talk of I simply cannot see as the cast is so strong; set 2, of the four photos I find two quite neutral (but of these one is exposed to make the bird look quite dark) and two yellow; set 3 (Jerusalem) looks fairly neutral in colour, but the exposure/light has made the bird look really quite dark and grey – even on the underparts; set 4 (Oxford) has variations in exposure, but the first is most neutral; set 5, shows six photos, with three rather yellow and three more neutral (though if you look at the skin colour you can see it is very slightly blue); set 7 (DB bird) shows the hand again to be slightly blue, which I suggest is making the bird also look rather ‘cold’. So, any real conclusion about plumage based on photographs has to be balanced by careful impression/observations made in the field/hand, otherwise they can become meaningless. Look at the (sadly) disasterous quality of the specimen photos in Dean and Svensson’s Siberian Chiffchaff paper – – where they are next to useless in illustrating what tristis looks like.

Maybe one question we should be asking is ‘What is abietinus?” and “What does it actually look like?’ I have to admit that my own view of what abietinus looks like is largely based on birds I have studied at Tring and then others assigned to the form in the field. However, many of the specimens of abietinus at Tring come from the Middle East on passage or wintering grounds, and perhaps (now that the genetic work in DB has been published) these features I am using are wrong. I have always felt that many specimens labeled as abietinus have plumage much more in common with tristis, and so perhaps that is what they may well have been. If you read the appendix at the end of the paper (linked above) there is a description of abietinus in which the form is described as very like colybita, but a little paler above and with darker legs.

Finally, I have seen many 100s of tristis in India, with a few Mountian Chiffchaffs amongst them, and also if you go to Kuwait in late winter or spring, you get an amazing and bewildering mix of chiffchaff types. In central/eastern India, I feel there is very little variation in tristis plumage, indeed the real dificulty is telling tristis from Mountain; the ‘abietinus-type’ birds are not there, so maybe they occur further west.

Reply ↓
Alan Dean
January 2, 2013 at 11:18 am

I agree with nearly everything said by Brian (including that the photos of skins in Dean & Svensson 2005 were useless owing to exposure problems!).
See my own comments on this general topic at:

Alan Dean
Reply ↓
Alan Dean
January 2, 2013 at 11:25 am

To me, the tristis images on the North Wales website look like slightly over-exposed (or colour diluted in bright light) images of tristis. The bird labelled as abietinus looks like a better exposed (or better rendered in light shade) tristis. That’s not to say they looked same in field – clearly they didn’t to observers – but they both meet the ‘tristis panel’ criteria.

Alan Dean
Martin Garner
January 2, 2013 at 7:32 pm

hi Brian

Thanks for this. Of course I understand images get ‘corrupted’ and photos need to be viewed with a certain amount of circumspection most of the time. Importantly though you seem not have referenced, the fact that accompanying the images in a number of cases a reference is made as to how the bird appeared in the field. In the case of the Foula bird I sat in a bank- in and out of sunshine and watched this little thing at close range. Some of my first thoughts were- aha- this is one of those grey and white Chiffchaffs- on account of it looking grey above, white below and with, at times, strikingly bright greenish fringes to wing and tail feathers. Perhaps I need to reset my hi-res eyes using a colour card ; )

There are a similar comments accompanying photos of the Doncaster bird and the Oxford bird

Happy New Year! Martin
Reply ↓
Ben Porter
January 2, 2013 at 6:53 pm

Thanks Alan,
I believe the general consensus as to why the chiffchaffs were though to be abietinus as opposed to tristis was solely down to the fact that they didn’t call with the classic bullfinch-like ‘hweet’. However, reading articles such as these illustrates just how variable they can be both vocally and in appearance, and so in future I think birds such as these (there are few more images here: if you scroll down) will be identified as tristis. Thanks again,
Reply ↓
James McCallum
January 4, 2013 at 9:50 am

Only just seen this excellent series of posts about Siberian Chiffchaffs. I particularly liked the extract by Magnes Hellstrom. I doubt that the following personal musings have any value in the Siberian Chiffchaff debate but I’d prefer to have an opinion based on field experience rather than totally accepting everything I read as gospel. The following observations were made a while ago and resulted from a series of long discussions with friends about their field observations – I realise that some of these points have now been highlighted in the posts but if nothing else we share some similar thoughts.

Over the last decade or so I’ve followed various papers and debates on the subject – I was left feeling confused by the whole topic, I also felt surprisingly down-hearted to have suddenly ‘lost’ one of my favourite late autumn/winter rarities in a cloud of uncertainty. Lots of what I was reading didn’t really fit with my personal experience, especially plumage criteria, so I decided ignore the debate and simply go back to the birds in the field and the firsthand experience previously gained.

Subsequently I’ve been lucky enough to see a few more Siberian Chiffchaffs. The debate has, however, made me look at them critically. I found that the field impression of the birds I was watching could vary enormously depending on light, background…etc. A bird feeding in birches in dull light could look very brown-grey yet in bright sunlight the same individual seen feeding low down in dark brambles could suddenly appear very grey-brown with silver-white underparts (although always with warm creamy washes to the cheeks and supercilium). I had wrestled with these colour changes in past years when trying to paint them in the field. It is also interesting to see how a bird’s flight feathers can go from being dull brown to bright greeny-olive depending on angle – this is often most obvious when a bird turns and is viewed back-on. I’m terms of how to record a bird’s colour I was left scratching my head – according to some recent criteria the appearance of several of the birds I had been watching could go from ‘classic tristis’ to ‘Eastern abietinus’ in the time it took a small cloud to pass across the sun!

The other eye-opener for me has been the impression of Siberian Chiffchaffs created by digital photography. On occasion a Siberian Chiffchaff that I have been watching has been photographed at the same time by observers standing close to me. Sometimes I have asked a photographer if they would send me a series of images by email and on seeing them I’m surprised how frequently the images bear little resemblance to what the bird looked like in the field. Sometimes birds with seemingly consistently brown-grey upperparts will appear in the images to have small blotches of olive in the lower scapulars and occasionally on the mantle. I find this hard to comprehend – I guess that there must be traces of olive in the birds’ plumage but it is not evident in the field – somehow the camera seems able to pick out the colour and enhance it?
Other photo effects are noticeable when a bird has been photographed in bright light, particularly against a dark background. In such shots a bird can be rendered very grey and white and some of the subtle warm washes in the face can disappear – yet the green edges of the flight feathers remain. The resulting images can look very much like a ‘Grey and White Chiffchaff’ and again bear little resemblance to what the bird looked like in the field. Presumably this is caused by over-exposure? I once had a series of images sent to me that made the bird look more like a very bright Bonelli’s Warbler than the rather plain brown-grey bird it really was! This experience has left me wondering just how frequent are truly ‘grey and white’ birds encountered? I’ve certainly never seen one – even the greyer of the tristis I seen always showed warm washes in the face and supercilium. Photos are great and very useful but with subtle species such as Siberian Chiffchaff they can create false impressions and I can’t help wondering if at times they can be a hindrance? Certainly I believe that there is a real possibility of observers making identification judgements regarding Siberian Chiffchaffs based on images that may not be a truthful representation of the bird in the field.

Recordings and sonograms appear to be far more reliable than photos. Personally I’ve always been a great believer in the value and reliability of calls in field identification – after all what is the point of uttering contact calls, threat calls, singing…etc. if your own kind doesn’t recognise or react to them.
Reply ↓
Alan Dean
January 4, 2013 at 4:20 pm

I think that a lot of so-called ‘confusion’ arises because people are sometimes fixated on the notion of ‘paleness’ when considering Siberian Chiffchaffs. Some are paler, others are not especially pale – see

Typical individuals from the core-range are not especially pale. Instead of fretting about ‘paleness’ observers would be better asking whether or not a candidate has the characteristic hues of ‘brown and buff’ in the right places and sufficiently restricted levels of olive and yellow. Note that these are not ‘any old shades’ of brown and buff but characteristic shades. It would be a real step forward if these characteristic hues of ‘brown and buff’ and their ‘rusty’ or ‘tan’ suffusions could be captured precisely in words. As the recent Dutch Birding paper demonstrates classically (the paper has nothing to do with calls), colour nomenclature remains very relevant (despite Mark Constantine’s failure to appreciate this in his new book). Unfortunately, it is an enduring problem and the necessary modern, reliable and colour-fast ‘colour guide’ remains a far-off prospect. Wide field-experience of tristis and careful consideration of ‘colour neutral’ photographs (see Brian’s contribution) remain the only available routes. Some of the issues discussed in this thread are not limited to Siberian Chiffchaff. They apply also to other taxa where allocation to form depends primarily on potentially subtle hues. A good example is the Isabelline Shrike complex. Here, too, light conditions and photographic vagaries can easily mislead. Witness the 1W on Shetland in September 2011, where some published photos portrayed a more Turkestan-like appearance (see comments by Martin elsewhere on Birding Frontiers and also the caption to the plate on page 426 in Birding World Volume 214, Number 10 (November 2011). Those who saw the bird in the field were able to make a balanced evaluation and identify it with confidence as Daurian. There is no need to ‘abandon ship’ on these sometimes subtle taxa, where hues are central to identification. Approaching observations with the requisite combination of care, realism and time (no snap judgements), many can be identified with confidence.
However, we shouldn’t expect to identify every individual and not encounter perplexing individuals. Some cannot be identified with confidence – because their features are too marginal or enigmatic (the unresolved question of hybridization then arises, among other factors) or because the light conditions are persistently unhelpful. Those have to be left unassigned.
Returning to call, that does of course provide invaluable information but, as Martin’s ‘Part 2’ begins to illustrate, there is still much to be learned about vocal limits and overlaps, as well as plumage limits and overlaps. The Scilly inornatus/humei was another example, from a different branch of the phylloscs. Hands up those who have total confidence about that bird based upon call?
Alan Dean
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Graham Gordon
January 4, 2013 at 11:32 pm

At the moment, on St Agnes, Scilly, there are maybe half-a-dozen or so Chiffchaffs of varying appearance. I had a chance to study them closely during the month of December, as three or four birds were feeding daily at point blank range on my lawn. I would describe three different ‘types’, none of which to me look like classic tristis, two of which I had the pleasure of watching on an almost daily basis for four months two winters ago. I’ll come to the latter birds in a minute.

The first ‘type’ of Chiffchaff -, instantly separable from the others at long range – is a fairly uniformly darkish, swarthy-looking bird, very olivey-green above and (at very close range) with plenty of olive ‘streaking’ below. It has a very obvious yellow eye-ring, a poor super, and a typical hoo-eet call. I’ve assume this (rightly or wrongly) to be a standard nominate British collybita. I’ve only seen one such bird like it in previous winters, and then (as now) it was quite striking amongst the more numerous Type Two birds that I have (until reading all this recent ‘stuff’) assumed to be abietinus. I think all Chiffchaffs are quite beautiful but these Type Two individuals have nothing particularly striking about them. They are just a sort of wishy-washy dull (pale) yellowy-olive above with rather off-white underparts, not particularly striking supers or eye-rings, quite ho-hum. They perhaps slightly overlap and blend into the Type Three individual that I scoped at point-blank range for twenty minutes on the exact same branch as a Type One bird on Porthkillier Beach. This bird was undeniably pale and ‘interesting’ on a brief first view at long range; and when examined closely, certainly looked a reasonable shout for a pale tristis in that its underparts were quite silky white, and its head was pale grey with a very decent super. There was the merest hint of warmth in the cheeks. However, it had a fairly strong olive-yellow wash to the upperparts from about halfway down the mantle to the rump, which gave it a slightly incongruous appearance, vaguely reminiscent of some of those really obvious Glaucous x Herring or Western x Glaucous-winged hybrids that you see, in that it looked ‘half-and-half’. It called just three times while I was watching it, a typical hoo-eet. It closely resembled a bird I saw at Lower Moors, St Mary’s, in early December that was singing a full tristis song, but which left me with a slight feeling of dissatisfaction about its appearance. I cannot help but think that the conclusion of this simple back-to-the beginning approach, as taken by James MacCallum above, is that some form of integration is going on somewhere and we will NEVER be able to be sure about anything less than a small percentage of our extralimital birds, i.e. birds away from the breeding grounds.

Missing from the current St Agnes picture, is, as I say, your classic brown-and-buff trisits as portrayed superbly on Alan Dean’s website under A Case Review of two birds on Scilly, October 2011. I saw that particular Siberian Chiffchaff alongside Alan – Hi, Alan, sorry I missed you this year, I was up on Fair Isle watching Magnolia Warbler instead – and instantly recognized it as identical to the bird(s) that had wintered in my garden earlier in the year. I’m not as diligent as Alan and I walked away totally happy after fifteen minutes, while he waited seven hours to hear it call (peep), which it did just once! The bird(s) that wintered in my garden gave me what may have been a fairly unique opportunity to watch a Sibe Chiffchaff almost daily for four months, right through to March moult and – just as I’d given up hope of hearing it – spring song. I have very extensive notes on the bird(s) and can confirm the instantaneous morphing of colour tones outlined by Martin so well. I say bird(s) because for about ten days around Christmas 2010, one would come into the garden and call plaintively and persistently for about fifteen minutes before dusk, until another one would zoom in from somewhere else on the island, and the two would then disappear to roost in the trees above my bathroom window! At no time did I ever hear anything other than the classic peep from either bird, though for a very brief moment when the original bird was clearly agitated and I was directly beneath it, the call ever-so slightly, but clearly split into a just discernible disyllabic pee-eep. Plumage wise the original bird was beautifully tinged with rusty ear coverts and a slight pinkish tinge to the flanks in early December, but I watched this gradually wear off and it became quite (boring) Booted Warbler-grey after the turn of the year. Elsewhere on the island two of the Type Two birds mentioned above – washed-out pale, yellowy looking birds – wintered at Covean Beach and could be seen at close range more or less daily. One of the equally striking dark olive-green Type One birds with prominent eye-ring popped up a few times around the garden in Jan-Feb.

As I think I may have mentioned elsewhere on this site, at the same time as my ‘type-specimen’ tristis turned up in early December, I went across to St Mary’s in company with Kris ‘Spider’ Webb and had decent, not exhaustive, views of what appeared to be half-a-dozen fairly consistent rust and ‘pink’ tinged Sibe Chiffs with matching exclusive peep calls. This year, not just myself and Spider, but also Ash Fisher, had at least one, maybe more, atypical birds (such as the singing Type Three bird above) that have left us scratching our heads a bit, and left a slightly dissatisfied feeling. This again, suggests to me, that some sort of integration is going on somewhere that is going to defy all our efforts to categorize many of the odd Chiffchaffs we see in the UK. Having followed Alan Dean’s intelligent, cautionary stance for many years, I was beginning to think Siberian Chiffchaffs didn’t exist! The two that then wintered in my garden made me think that Siberian Chiffchaff HAD to be a separate species. Now, I’m on the point of giving up! Especially after seeing that Magnolia Warbler!!
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James Walsh
January 29, 2013 at 11:02 am

Hi Graham, it’s Walshy here, occasional New Jersey birder in the 90’s, we got sent to Coventry during the heady book publication attempt era, my mate saw a Chiffchaff on the River Irwell recently, I would like to email photos to you for opinion, my email address: [email protected], hope you’re doin fine, James
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Alan Dean
January 5, 2013 at 9:49 am

Points to note here are: (1) that, despite some ‘instantaneous morphing’ of the Chiffchaffs he’s been observing, Graham was able to make what he considered to be reliable judgements of their more steadfast appearance via appropriately detailed and prolonged observations; (2) Graham talks of my ‘cautionary ‘ approach. He’s not the first – but in the past some have asserted the opposite (see Surfbirds thread)! Well, yes, I certainly do not advocate throwing caution to the wind. However, Graham (and James) should not forget that the tristis panel ‘opened up’ the status of Siberian Chiffchaff (they did not close it down) and well ahead of the ‘official position’ in most of western Europe. The panel concluded that tristis was simply a scarce migrant and winter visitor and not a true rarity. But that doesn’t mean adopting an anarchic, ‘anything-goes’ approach. Sensible plumage limits are still appropriate (see my last post) – especially while the issues of hybridization and haplotype variation remain unresolved (just hold on a while – the research is in progress!). The plumage limits I advocate mirror the appearance of the vast majority of the individuals which are encountered where the species is numerous (I echo Brian’s experience that nearly all these birds consistently exhibit the characteristic hues of ‘brown and buff’ and have adequately restricted yellow and olive). If it becomes firmly established that a significant percentage of individuals reaching western Europe is more variable than among the population as a whole, then that in itself would raise questions about the geographical and genetic origins of the birds.
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James McCallum
January 5, 2013 at 3:09 pm

I’ve very rarely contribute to forums and when I have its always a result of going stir-crazy from being stuck indoors with a cold or bug – I hope I feel better soon!

Anyhow – I would never wish to sound disrespectful of Alan’s, the Tristis Panel’s or any other individuals’ work. I totally acknowledge the great value of the role of the Panel in helping build the foundations of the current studies. I’m full of admiration of those who dedicate their time and energy to such daunting tasks especially knowing that all their thoughts and findings will face intense criticism. Equally I do think that it is good to form personal opinions especially those based on firsthand experience rather than go along with everything that is written. No doubt some of these opinions will evolve or be proven unreliable or simply wrong – such is the process.

I agree with Graham that it is possible to witness Chiffchaffs in a whole array of different plumages. In Norfolk we see most variation in late autumn – by winter usually they will have become much scarcer. In some late autumns we often get ‘falls’ of migrants which sometimes contain small numbers of Chiffchaffs. Mainly these are all remarkably similar-looking, classic collybita-types but at other times their numbers may be dominated by more variable duller-plumaged birds which give a range of calls most often variations of the ‘sweeoo’ calls (but seldom ‘hueet’) a few sound more reminiscent, to me at least, of some calls of Hume’s. Very rarely we have had ‘mini-arrivals’ of very odd-looking birds – quite dark and contrasting brownish birds – very different to anything described in the posts. Smart birds but I haven’t a clue what they are or where they come from.

That said, I think that tristis candidates can be readily be picked out from all these different plumages. However, I can only base this notion purely on limited firsthand experience of tristis – 20+ in Norfolk, 8 in Shetland and 8-9 wintering birds in Cornwall. With the exception of the most of the Shetland birds virtually all the others were calling regularly and I noted no variations in their calls. The vast majority of these birds I found for myself which has often allowed long and interrupted observation and several individuals have stayed for several days. To date all birds that have looked ‘right’ have sounded ‘right’ and vice versa. I’ve not yet heard a classic tristis call from any other Chiffchaff type.

Occasionally I have seen a bird that on first glance resembles a tristis but very quickly it is seen to look ‘not quite right’ – longer views have showed obvious blotches of olive in the scapulars and mantle, sometimes traces of yellow in the face or underparts (and perhaps a more contrasting face pattern??) Interestingly all such birds have called ‘sweeoo’ or something similar reinforcing the initial doubts about the bird’s appearance. Seemingly I’ve been lucky in that all the tristis I’ve seen have conformed to a distinct type – surely that must stand for something.

I totally agree with Alan that it is important to observe birds over long periods – although the effects of light…etc. can have huge influences on a bird’s appearance I think that our brain is capable of filtering out the extremes and making a more realistic judgement of what the plumage looks like in typical/average light conditions. I also agree with Alan that many tristis have a distinct ‘look’ about them and I do share the same difficulty of how to express describe this ‘look’ in words.

There is clearly something about the tones and hues of the plumage that make them stand out from the majority of other Chiffchaff plumages – in addition there may be other subtle plumage characteristics – perhaps weaker facial makings i.e. weaker-marked cheeks and eyestripe, in turn resulting in less contrast in the lower eyering?? The combinations of differences are so slight that it is difficult to put your finger on any one feature.

That certain ‘look’ or ‘feel’, in common with ‘jizz’, is so hard to put into words – ultimately perhaps you have to experience it to understand it? The nearest I’ve seen to somebody capturing the ‘look’ or facial expression of passerines is in the work of Lars Jonsson or Leo-Paul Robert – wonderful skills.

For me photos, although invaluable in many great advances in bird identification, I don’t always find particularly helpful in representing the field appearance of Siberian Chiffchaffs. I think the plumage and features are possibly too subtle and, as Brian Small detailed, there are currently too many variables in the process and additional inaccuracies can occur when viewing the images on computer monitors.

Personally I fully embrace the recent interest in sound recording as I think that it is important not just in identification but also interpreting behaviour…etc. But it is still only part, albeit an important part, of field study – I’m assuming that everybody still has birdwatching as their main hobby – or am I as Victorian in my approach as I’m beginning to feel?!
(Alan mentions the calls of the Scilly Yellow-browed/Hume’s – I have heard a few recordings and seen some images. I do have an opinion based on past experiences of Hume’s (3 call types) and Yellow-browed Warblers with less typical calls – but it may not be the right answer!)

In the case of Siberian Chiffchaff personally I think I’d prefer to trust a sonogram before a digital photo. But I don’t think anything is totally reliable. This autumn I heard a quiet ‘tzick’ call repeated from some coastal sycamores. The call was not unlike a quiet version of an Arctic Warbler, eventually I tracked down the culprit – a typical-plumaged Collybita! Several years ago I had a mixed-singing Willow Warbler that returned two years running to my local wood. Its song would regularly alternate between typical Willow to Willow+Chiffchaff, then for two mornings only, it inexplicably introduced long, loud sequences which to my ear sounded exactly like a Tree Pipit (a species that doesnt regularly occur there)! Make of this what you will. I guess it comes down to how much value you want to attach to such vocalisations. Personally I make a note of them then largely ignore them – on the whole calls and songs are pretty consistent and when I used to do regular bird surveys I’d base 85-90% of woodland work on calls and songs.

I’ve pretty much exhausted my observations Siberian Chiffchaffs – the observations are highly personal and probably have no bearings on the bigger picture – they are, however, made from 30 years observation, predominately in the same small area of the North Norfolk Coast where I have watched many hundreds of migrants Chiffchaffs pass through during the late autumn and early winter.

What I agree with wholeheartedly (possibly with the exception of adults in late summer) is Graham’s statement ‘’All Chiffchaffs are quite beautiful’’ Never has a truer statement been written about the species.
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Graham Gordon
January 5, 2013 at 5:27 pm

Ah, yes,James: those late summer adults! I’ve seen a few here in late July-August taking roughly 4-6 weeks to go through their moult and they can become extremely tatty, with almost bluish heads, reminiscent of Tennessee Warblers. One morning in late June, I watched one poor, bedraggled little adult feeding two ‘massive-looking’ fresh juveniles that almost looked like Garden Warblers! A couple of days later the poor little thing was back in the treetops singing and perhaps advertising for the missus to come back and knock out another brood? And, yes, too, to your statement defending birdWATCHING (as opposed to birdING) as our primary modus operandi. We must never forget that.
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Alan Dean
January 5, 2013 at 3:39 pm

A very welcome over-view James and a good read!

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Andy Mould
January 6, 2013 at 4:02 pm

All very interesting but hugely confusing too! Going back to the original Dutch paper (of which I’ve only seen a poor quality copy), those birds pictured and (initially) identified as abietinus, look like tristis, or some tristis-type intergrade to me. As others have said, tristis is surely a more ‘colourful’ bird, essentially displaying brown and buff hues. Perhaps wrongly (?), I have always thought of abietinus as being more grey and white. I can’t even see the ‘abietinus supercilium’ identified by ringers in plate 532; it appears to display yellow or buff to my eye.

I am no expert, far from it, but always believed that I was seeing a very small number of abietinus Chiffchaffs in most, but not all, autumns on Holy Island, Northumberland anytime from the 2nd week in October onwards. I base my identifications on the following criteria:

1. Generally look immediately greyer than all collybita (even greyer collybitas), sometimes even at distance
2. Supercilia always long and whitish (contra. illustration in ‘Collins’) and often rather narrow
3. ‘Clean’ underparts, usually whitish or off-white, sometimes grey, but with any yellow always restricted to a slight yellowish wash on upper breast, flanks and under-tail coverts. Yellow never as extensive as on collybita
4. ‘Cold’ grey or brown-grey mantle, usually lacking green tones
5. I sometimes record the legs as ‘jet black’ but am uncertain of the importance/relevance of this.

In most years I would guess that maybe 20% or more of collybita/abietinus birds I see cannot be identified to either race. For example, in the exceptional year of 2010, I left 3 of 13 birds (=23%) as unidentified. Some of these birds appeared to show characteristics of both; maybe some were intergrades? I find it hard to equate my remaining 10, mostly greyish birds, with tristis.

Even more interestingly, some posts have touched on the ‘old chestnut’ of ‘Grey-and-White’ Chiffchaffs. On two occasions, I have found birds that show a complete absence of brown, buff, yellow, olive or green hues throughout the plumage. The first of these was a bird at Alnmouth, Northumberland on 15th November 1997. Watched on and off for a period of 30 minutes in excellent visibility, in varying light conditions from bright sunshine to shade, and down to under 20 yards, this individual was strikingly grey and white with a long white, well-defined supercilium and a narrow, dark eye-stripe. The upperparts were grey, probably very similar in shade to Dean’s ‘pale neutral grey’ – see Alan Dean’s letter about ‘Colour nomenclature and Siberian Chiffchaffs’ (Brit. Birds 101:146-149), and the underparts a grey/white or dirty white with a pure white throat and chin. The ‘face’ and ear coverts were very plain giving the bird a ‘timid’ look. No wing-bars were visible and the legs were jet black. The bill was dark but never seen well as the bird was constantly on the move. The bird was submitted as fulvescens, which I believe, at the time, was treat with tristis.

After finding and observing many pale and washed out ‘eastern’ Common Chiffchaffs, 10 years passed before I had the opportunity to study another solely grey and white individual. Two birds together on Holy Island, Northumberland on 14th October 2007 were very similar to the Alnmouth bird described above. They too lacked all the colour hues mentioned above and were entirely grey and white. At very first glance, with just one partially obscured bird, a sylvia warbler was what first came to mind.

My dear friend, the Late Andy Booth, was co-finder of the Alnmouth bird and a couple of years ago he commented that, from many years of regular birding on the Yorkshire coast, Scillies etc, he had only seen one further completely grey and white plumaged Chiffchaff. That was an individual at Flamborough Head, I believe in the late 90s or early 00s’. Like others, I believe that these wholly grey and white Chiffchaffs, that display no other colour hues, are much rarer than other ‘types’ we record.

In conclusion, I look forward to the day when the whole Chiffchaff complex is finally sorted out, although I can’t see it being any time soon! In the meantime, I shall continue to enjoy looking for non-collybita type birds in late autumn.
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Graham Gordon
January 6, 2013 at 6:48 pm

It might be worth noting here something that may have become lost in the passage of time regarding a very similar species, Willow Warbler -, a bird that has received far less attention in recent years, racially speaking. It’s over twenty years since I last saw my copy of Williamson’s Ringer’s Guide to Phylloscopus Warblers, but if memory serves, there were some odd things going on with P.trochilus,back then, too..I seem to recall discussion about colourless brown and white birds that were initially thought to be P.t. acredula when trapped, but were later controlled holding territory in, I think, places such as the Western Isles, the Scottish Highlands, and also northern England (was it Lancs?). Further studies revealed that such birds were not, in fact, especially rare. This idea we have about colour clines in phylloscs from west to east, is clearly not as simple as we might like. In fact, I remember being surprised when I came across two mid-November Willow Warblers in north-east England back in 1990 that were as bright yellow below as any I’d ever seen, having assumed a bird that late ought to have been brown-and-white,(acredula) or even better still, grey and white (yakutensis). I saw one such bird all-too-briefly on St Agnes in late October 2009 that got away from me just as I’d established primary projection and leg colour to confirm it was Willow Warbler and not Chiffchaff. (Anyone recall DIM Wallace’s classic comment in BB in the mid-80s about a grey and white P.trochilus at Flamborough in October that ‘had him all over the genus until it obligingly started singing.’?);And then, all of a sudden, in 2012, in response to a Surfbirds thread regarding a Chiffchaff/Willow Warbler in Alaska, we see a load of photos of Willow Warblers in Japan, assumed to be yakutensis, that look hardly any different to our birds!
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December 16, 2013 at 6:51 pm

I have some photos taken in field 12.11.2013 of a bird i am pretty sure is tristis in south Norway.
These photos is taken a very nice autuum day, and shows a bird that shows all the extremes that you write about in one and the same bird.
I have not seen a dokumented bird whit these extreme morphs.
If intersested my e-mail is
[email protected]