More thoughts on ‘grey and white’ Chiffchaffs

from Alan Dean

Hello Martin and thanks for the response.

Below is a composite image showing

(a) a photo of the St Agnes, Scilly, Chiffchaff from October 2011 (the bird I have long featured in discussions as a classic example of a ‘grey and white’ Chiffchaff and with which you will be correspondingly familiar);

(b) a copy of the image by Anthony McGeehan of his suggested abietinus on Inishbofin in October 2014 (I trust Anthony is happy for me to repeat it here).

I do not suggest that either image is colour perfect nor that their appearance in the field would not vary somewhat from their depictions here. I do suggest that there is a close similarity between the two individuals in these photos and that they are ‘the same kind of beast’. I have selected an image of the St Agnes bird which has a somewhat comparable posture to the Inishbofin bird.

There are further images (and plenty of discussion!) of the St Agnes bird on my website: http://deanar.org.uk/tristis/tristis.htm 

Regards, Alan

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7 thoughts on “More thoughts on ‘grey and white’ Chiffchaffs

  1. Alan Dean

    A little more,,,

    In discussions of this topic (here and on Surfbirds), there has been a tendency for others to tell me what I mean by ‘grey and white Chiffchaff’. Clearly, that is back to front! There have also been mistaken suggestions that the ‘Bonelli’s’ analogy relates only to relatively prominent olive fringes to the remiges. Let’s try and nail this down once and for all. The Chiffchaff which I describe as a ‘grey and white (Bonelli’s-like) Chiffchaff’ and which I have documented and illustrated in greatest detail is the St Agnes, Scilly, individual from October 2011. It was observed by multiple observers. My website includes eight different photographs, including two by a second photographer (Chris Turner, to whom many thanks). There is the expected slight degree of variation but all images, in varying postures, surroundings and light conditions, portray fundamentally the same ‘grey and white’ appearance. There will always be debates about what constitutes ‘grey’: it covers a range of hues, of course, and ‘grey’ cannot be applied in an absolute way. It has to be interpreted in context: in this case the range of plumage variation encountered among Chiffchaffs. So, to borrow a concept from taxonomic nomenclature, in discussions of what I mean by a ‘grey and white (Bonelli’s-like) Chiffchaff’ the St Agnes Chiffchaff is the ‘type specimen’.
    If its depiction in Anthony McGeehan’s photo is at all accurate, then his Chiffchaff on Inishbofin evidently ‘matches the type’. Note, too, the comments which Anthony makes about the bird in his Facebook text. He wrote of it as ‘dramatic’ and ‘ghostly’ and that ‘if Chiffchaffs as pale as the top individual exist, where does that leave any attempts to assign Siberian Chiffchaff to a different tribe?’ Those comments mirror discussions of ‘grey and white’ Chiffchaffs from ‘Siberian Chiffchaff revisited’ onwards. They encapsulate the central issue: such birds still get identified by some as Siberian Chiffchaffs. The findings of de Knijff et al. indicate that many ‘greyer’ Chiffchaffs (sensu lato) carry the mtDNA of tristis. So, are all ‘greyer’ Chiffchaffs assignable unequivocally to tristis? I think not. The Inishbofin Chiffchaff and Anthony’s comments upon it are a valuable contribution to that debate. Certainly, people are entitled to question my contention that not all ‘greyer’ Chiffchaffs are tristis but they cannot justifiably maintain that such birds do not exist and are merely a ‘mirage’.

    regards,, Alan

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  2. Kester Wilson

    Hi all, since living in Cornwall I have trapped a good number of tristis. Most having the expected plumage and calls, but occasionally you get birds that don’t have the expected tristis call. Over the years these birds have been fairly infrequent, but this year I have had quite an increase. Has anyone else noticed? I have sent feather saples off for analysis. It would be interesting to get a bigger sample of these odd calling birds. In the past birds with hints of yellow or green in the mantle have come back as tristis. Assume the odd caller prudomently come from the contact zone? Are they from mixed pairs and surely if you had a good enough samples the DNA wouldn’t all come back as tristis. Not all the females from mixed pairs would be tristis? Would they? Kester

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    1. Alan Dean

      On plumage limits, call anomalies and hybrids:
      Together with the plumage limits of thoroughbred tristis and abietinus, the question of hybrids is at the heart of much of the controversy. A central tenet of ‘Siberian Chiffchaff revisited’ was that core-range tristis exhibited characteristic ‘brown and buff’ hues (rather resembling Caucasian Chiffchaff P. lorenzii). Yet Chiffchaffs which lacked these hues, and which we labelled as ‘grey and white’ (see earlier ‘definition’), were also ‘regularly’ identified as tristis in the UK. (Aside: In that paper we over-estimated the proportion of reported tristis which exhibited the ‘grey and white’ livery. It has become apparent that descriptions at that time often referred to perfectly typical ‘brown and buff’ tristis as ‘grey and white’. The term was (and still is) applied by some to any Chiffchaff which is strikingly deficient in olive and yellow hues.)
      Such ‘grey and white’ birds, as defined in the paper, did not resemble lorenzii and were more suggestive of a ‘Bonelli’s Warbler’ P. orientalis / P. bonelli. We suggested that such ‘grey and white’ Chiffchaffs were, in fact, closer in appearance to some paler abietinus than they were to core-range tristis. Although we did not rule out that some may have involved ‘extreme’ examples of tristis, we suggested that others included paler abietinus and hybrids between tristis and abietinus. Cue ten years of debate about the plumage limits of tristis and abietinus, the very existence of hybrids, and the extent to which calls are diagnostic!
      Prior to and during these ten years, a Russian team led by Irina Marova has conducted research in the overlap zone between tristis and abietinus and, based upon plumage, biometrics, song anomalies and mtDNA, they have concluded that a significant level of hybridization is proven, though the width of the ‘reported hybrid zones’ is relatively restricted. Also during these ten years, it has been demonstrated beyond doubt that calls are not as diagnostic as has at times been claimed. The problem with settling the hybrid question unequivocally is that, so far, virtually all genetic testing has been based upon mtDNA – which is inherited only via the maternal line. That is, if the mother is tristis then the offspring will have tristis mtDNA, irrespective of whether the father was tristis or abietinus. F2 hybrids etc. could also carry tristis mtDNA. Marova et al. found that 88.5% of the birds they identified as hybrids carried tristis mtDNA. Thus, if they were hybrids, mtDNA analyses of most ‘anomalous-looking’ or ‘anomalous-sounding’ extralimital tristis would still be expected to return tristis mtDNA. At first sight, that most hybrids diagnosed by Marova et al. carried tristis mtDNA seems unexpected but such ‘biased sex ratios’ are not unprecedented among hybrids. As well as the obvious explanation, that most hybrid pairings are F tristis x M abietinus owing to sex-biased selectivity, there are other genetic factors which are beyond my competence to discuss (or understand!) The conclusions of Marova et al. are still not universally accepted. I don’t know for certain whether they are right or not (again, it’s beyond my competence to judge) but, when faced with anomalous Chiffchaffs, I certainly take into account these researches and my texts take them into account. Only nuclear DNA analyses will provide unequivocal answers.

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  3. Kester Wilson

    Hi Alan, I am aware of the limitations of mtDNA, but from what I gather it’s the most practical and straight forward method in use. With the collybita population increasing and the abietinus population reducing in Europe, is anyone aware of what is happening in the east? I can see how a small female tristis may go for the larger male abietinus but with other populations changing couldn’t birds in the east be doing the same? There may be more out of range birds than the reported narrow contact zone? There has been a good sample of birds with tristis DNA and from what I gather no abietinus DNA has been recorded. I wonder if the continuing DNA sampling may start throwing up tristis-like birds with abeitinus or collybita DNA if populations are changing. As regards the strange birds I’ve trapped this year, they’ve given a collybita type calls but plumage-wise no different to birds that have come back with tristis DNA.

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  4. Bryon Wright

    Martin, Remember the Bermuda Phylloscopus, it morphed constantly in every photo. Presumably, morphing is hip-hop speak for what the French Impressionists called the transient effect of light on form. I do not fully understand the grey and white concept yet. Admirably, Alan Dean describes some of his warbler colors like Thomas Hardy, eulogizing the darkling thrush, spectre grey perhaps? His use of the word mealy for instance, puzzled me a few years back. I now know Alan uses it in the sense of being hoary, not sandy. In this sub-grouping of warblers the colors are not that difficult and old British Army, well washed khaki is easy to remember. Greenish, greyish, or brownish-olive with another adjective perhaps pertaining to a predominant, qualifying color bias or hue is all that is needed. These subtle, but simple neutral colours serve most of the non-tropical forms, up to eastern-crowned.
    Bryon Wright

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  5. Bryon Wright

    Martin, with regard to vocals, the Kuwait the reed-beds at Jahra had lots of chiffchaffs and my friends told me in the light of new information, that certain individuals that called like tristis were not tristis but chiffchaffs with a tristis like call. The Sound Approach, to Siberian Chiffchaff id. is a scientific, simple solution, to something that has been on mind for years and in my view they solved my problem for me. A short potted history of historical warbler id., Brooks said to Alexander that all the (Asian) warblers will all be differentiated in the future by vocals something that Alexander possibly disagreed with except in the case of the chiffchaffs! I just hope that it is not the case that in the future someone will be writing that Siberian and Iberian and Caucasian are just balls of fluffy genetic detritus with vocals to match!

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