- An interesting discussion this, which draws me into another aspect, i.e. that of accelerated speciation via hybridisation.

The last time I was in N. Africa (many years ago) there was of course no such thing as "Atlas Flycatcher", so I can claim no experience of this form at all.

This may be a bit over simplistic, but looking at the ranges of Pied Flycatcher and Collared Flycatcher in my older "Collins" I notice that there is an area of overlap around Algeria/Tunisia. Atlas Flycatcher could well have evolved as a direct consequence of interbreeding in this overlap zone, where the resultant hybrid form might adapt and prosper better than either of the original parent forms, and thus enjoy a "shorter cut" towards becoming a full species.

I suggest that where this happens within a relatively short period of time, there might still remain an unusually high degree of variation in the DNA of individual Atlas Flycatchers, with some individual bias towards the DNA of either of the original parent species. This could also of course manifest itself in certain plumage characteristics.

All this makes identification with certainty no easy matter, especially if the parameters of acceptable variation within this relatively recently described species have not yet been formulated.

Regards,
Mike P.

Ok, thanks for clearing that up, I didn't realise that Vagrant recording was so complicated! I'd have thought they would be happy to put it on the British list anyway!

-- Edited by Rory Newton on Monday 7th of May 2012 01:09:11 PM

Rory Newton wrote:

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Ian McKerchar wrote:

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I am pleased that you find this bird 'completely obvious' Rory, so please feel free to enlighten me as to what makes it definately an Atlas Flycatcher

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Firstly, and mainly the white patch on the birds face is so large(and in one single spot), which is far Larger than any other of the Black and White flycatchers, and so well defined that I'd have thought this would have clearly abolished any doubt of the bird being a hybrid.
Anyway, which species is the bird supposed to be a hybrid with?

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I must admit I chuckled slightly with your ' completely obvious' comment? I was going to reply but Ian pretty much said what I was. The obvious presumption with regards hybrid would be Collared x Pied.
In the hand analysis (which is more productive for ID reasons) has been unable to determine what it is, so it is patently obvious it isn't 'completely obvious'. The prospect of ID via DNA has the potential to really open a can of worms. For this reason alone I haven't made the attempt for I must say is a rather smart individual.
What i must add is is Atlas Flycatcher really identified as a possible/potential vagrant in the UK? A fairly short range migrant within its given range and yes they have appeared in Italy and Spain, but another 1200 miles (at least) further north than the Spanish bird? Not impossible but improbable I think.

Cheers
Jason

Rory Newton wrote:

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Hi,
Can anyone please tell me why Rare Bird Alert, Birdguides and websites of a similar nature are still announcing the Flamborough Head Atlas Flycatcher as 'Possible Atlas Flycatcher' when it is completley obvious that it is an Atlas Fly? Why, after catching and examining the bird, are the BOU still waiting for DNA results to confirm the birds identity?
Thanks,
Rory

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It's not "completely obvious" to a lot of people Rory, that's why there is still doubt

Rory Newton wrote:

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Firstly, and mainly the white patch on the birds face is so large(and in one single spot), which is far Larger than any other of the Black and White flycatchers, and so well defined that I'd have thought this would have clearly abolished any doubt of the bird being a hybrid.

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Unfortunately not Rory.

No one is actually saying this is a hybrid by the way, just that in such an extreme vagrant context it should be ruled out due to the possibility of potentially extremely similar hybrid offspring. As for which species may be involved in parenting such a hybrid Collared x Pied is perhaps most likely.



-- Edited by Ian McKerchar on Sunday 6th of May 2012 06:41:30 PM

I think there's some debate about the bird being a possible hybrid. Only a DNA analysis can confirm it's true identity.