I think I am just about done with my
Siberian Chiffchaff reading. It has embraced a wide spectrum of material and is slowly eroding my will to live. However, I would like to impart at least the essence of this journey via NQS, and have decided to begin at the end. So, here is the bottom line...
- If it looks like a tristis, sounds like a tristis, and has the DNA of a tristis, it's a tristis. Sorted.
So just get out there, find yourself a cheery little 'pale and interesting'
Chiff, take a description, record its call/song, and pop that dropped feather/fresh poo into an envelope addressed to Prof Martin Collinson at Aberdeen University.
Yeah, right...
Or, you could do what I've done. Read enough bumph to convince yourself that any pale and interesting
Chiffies you come across are pretty much guaranteed to be
tristis. Forget the DNA test. Enough people have already been down that road to persuade me that birds which look like a
tristis will return a DNA test result saying exactly that. If you hear it call, great. A nice, flat, sad 'eeep' or 'iiihp' (at approximately 4.5 kHz, for those of you with perfect pitch) will do nicely. If you don't? Never mind. Almost always, if it looks like one, it will call like one.
Having said that, there are a couple of ways you could get yourself in a pickle. The first is by worrying unduly about the F-word...
Fulvescens
This word crops up everywhere, and generally is used to describe birds which differ in appearance from so-called 'classic'
tristis (which show no yellow apart from at wing bend/underwing, and no olive in crown or mantle) by having some limited yellow/olive in their plumage. Like these birds...
 |
Top two: one of the Colyton WTW birds
Bottom two: Chideock WRC bird (RH photo courtesy Richard Phillips) |
Note yellowy-green on wing edges, tail, etc. Frequently I have seen '
fulvescens type' used to describe a
Sibe Chiff like this. Unfortunately, when bandied about in birder chat the term seems usually to be applied in a disparaging way, inferring that the bird either is not a
Sibe Chiff at all, or is some kind of tenth-rate one. However, I have read enough to be very confident that the vast majority (if not all) birds that look like those two above will be absolutely stuffed to the gills with
tristis DNA. That's good enough for me. They are
tristis. Probably from the W end of the range, but still
tristis.
The next two beauties are seemingly
not fulvescens type birds...
 |
Bottom left: Kilmington WTW
All others: Colyton WTW bird #2 | |
These two birds are closer to 'classic'
tristis than the top two. But, for me,
all four are still
tristis. The three pics of Colyton WTW bird #2 illustrate how cautious we need to be when assessing colour tones just from photos. They're all slightly different, and prove to me that a description based on just an image is not trustworthy.
The other way you might get your underwear knotted is by worrying unduly about the dreaded...
Contact Zone
This is the vast mixed playground where
abietinus and
tristis overlap, and little chiffing hybrids are made. Drilling down into the genetic nitty-gritty of birds in this zone is the proverbial can of worms. Even well to the E of this zone, on the West Siberian Plain, some of your pukka
tristis are quite likely to carry tiny, tiny bits of
abietinus baggage. It's a mess, frankly. And the only way I am able to deal with it from an everyday birding perspective is to leave the lid on.
The obvious question is, surely at least
some of our pale and interesting
Chiffs must be dodgy hybrid/backcross beasts? The logical answer has to be yes. And what about
abietinus? Well, maybe...
But...
For a start, as far as I can discover, very few
abietinus Chiffies have been proven by DNA in Great Britain and Ireland. Something like nine in total, as of a couple of years ago. And, importantly,
abietinus doesn't appear to look like a
Sibe Chiff. As far as mucky hybrid things are concerned, well, it must theoretically be possible that your putative
Sibe Chiff will look like one on the outside, but be a genetic smorgasbord on the inside, but the rule seems to be that
Sibe Chiff candidates - including so-called '
fulvescens' types - give
tristis DNA results when tested.
All the above is admittedly a very simplistic treatment of what is clearly a complex issue. That's deliberate. I do not wish to make this the dullest NQS post ever by quoting figures and citing various 'authorities' left, right and centre. What I want to do - and what I'd love any reader to be able to do - is be confident that the pale and interesting
Chiff which has just crossed our path can be indentified without a massive palaver. My own treatment of the little cuties will be as follows...
- Is its plumage somewhere on the spectrum of tristis - including so-called 'fulvescens'? Yes? Have it.
My research into this has convinced me that at least 99% of the time this will be a safe ID, and for a bird that is not mega-rare that's good enough for me. If it calls, great. But I've spent quite a lot of time with five different birds this winter, and I've heard just one of them call, on one occasion, three times. As far as I'm concerned, it doesn't need to call.
But wait a minute! My county needs the call, or song, for a tristis to be acceptable.
This is a fair point.
Sibe Chiff is no longer a BB rarity, but it is still scarce, and records are now assessed at county/regional level. Speaking personally, my local area's recording policies are not going to affect my own. But perhaps you feel differently, and are not happy to count birds which would be 'unacceptable' to your local records committee. If
you won't count a
tristis as a
tristis unless you hear some sort of vocalisation, fine. Who am I to dictate how you should handle your own records?
As for me though, a sight-only record will be fine.
What I've summarised in this post is my own little
tristis odyssey, and the sentence above is where it's taken me. Hope you've enjoyed the ride...
I don't normally do this, but I want to close with just a few words of appreciation for help along the way. Thanks go to Martin Collinson and Mark Lewis, for kindly sending me pdf copies of their respective BB papers; to Mike Langman, Joe Stockwell, and several Twitterati for encouragement of various kinds; to Richard Phillips for the smart photo of the Chideock WRC bird, and finally to Lee Evans for some forthright debate. I know Lee will disagree with my conclusion, but that's okay, he doesn't have to live with my questionable standards.