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Pied Flycatcher (presumed) Flamborough Head 28 April 20012

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  • Scroll down the link below. Check tabla 1 for wing lengths (media and deviation) of an iberiae population from central Spain, all breeding birds, 892 males and 1136 females.

    http://www.vertebradosibericos.org/a.../fichypid.html

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    • Originally posted by GMK View Post
      I don't know where Lars got his data from, but I would be amazed if he hadn't measured birds himself and probably at Tring; there is a series there, after all (alternatively AMNH).
      The Flamborough bird will have been measured as max chord, but wont Tring/museum birds have been measured as min chord (and so be shorter)? I think min chord is also common for Scandinavians?

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      • Originally posted by LeeEvans View Post
        The South Landing male was a pretty unique individual - staying at one site for the best part of two weeks - fairly typical of North African/Iberian vagrants in our country but virtually unheard of in a migrant Scandinavian/East European-bound Pieds.
        It might be significant that it also 'lost' two tail feathers. This does have an energetic cost to the bird, which might have influenced its decision about when to leave.

        But why assume it was heading east? Maybe it was a British bird heading north? Wheatears and Redstarts, presumably also heading north, have been hanging around in southern England for days this spring.

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        • Originally posted by Motmot View Post
          Scroll down the link below. Check tabla 1 for wing lengths (media and deviation) of an iberiae population from central Spain, all breeding birds, 892 males and 1136 females.

          http://www.vertebradosibericos.org/a.../fichypid.html
          Hi Eduardo, hope all is well with you.

          To expand on your post, the wing length data are 78.3 mm +/- 2.1 mm for males (892) and on average shorter for females at 76.3 mm +/- 2.6 mm for females (1136). The Flam bird was measured at 83 mm, but with the proviso that we don't know how close to the true value that measurement is.

          F.
          OBC John Peel Awesomeness
          The little things they make me so happy, all I want to do is live by the sea...

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          • I'm not in the least surprised.

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            • Originally posted by mafting View Post
              But why assume it was heading east? Maybe it was a British bird heading north? Wheatears and Redstarts, presumably also heading north, have been hanging around in southern England for days this spring.
              Seems a fairly safe assumption to me; there's no part of Britain to the north of Flamboro' (just lots of sea!), but it is a good landing / setting-off point for Scandinavia for any bird that had been drifted west of its normal route by the east winds at the time it turned up.

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              • ''But why assume it was heading east? Maybe it was a British bird heading north? Wheatears and Redstarts, presumably also heading north, have been hanging around in southern England for days this spring''

                Richard, you make a reasonable point but although some Northern and Greenland Wheatears have been held up at some inland sites for up to a week, it is mainly Ring Ouzels that spent up to two weeks on site. I know of very few migrant Common Redstarts that held on for more than 3 days at one site and I don't know of any Pied Flycatchers that stayed more than a day. In contrast, this bird stayed at South Landing for virtually two weeks (13 days in total) - fairly typical for an overshooting Iberian/North African vagrant but virtually unheard of in a UK-bound Pied Fly or one bound for Scandinavia, Poland or European Russia.

                If I am going to follow Martin Collinson's DNA findings that our South Landing bird is nothing more than a variable extreme Pied Flycatcher (plumagewise), this really leaves us in a difficult place. Surely no one can argue that the South Landing bird was not a deadringer in appearance for either Iberian Pied or Atlas Pied Fly and with that clearly being the case, there is no way that we can ever be confident of identifying an out-of-range individual of either species if ordinary Pied Fly can so accurately portray both species in appearance. It is a great shame that nobody sound-recorded this individual as it would of been interesting to compare the sonograms. All 3 of these species are quite different in song, although of course, vocalisations/dialects seem to be the first thing that changes once populations are in isolation.

                The variation in measuring procedures also worry me but the fact that over 1500 trapped Iberian Pied Flys only have a maximum length of 80.3 seems tp place this bird (at 83) outside of the known range. Out of interest Andrea, what were the equivalent measurements of your two Sicilian ''Atlas Pieds''? I realise that there is extreme variation between any species but this is the first example of such I have seen in such a beautifully well-marked ''Pied Flycatcher''

                I attach below some shots of a typically well-marked Pied Flycatcher -:

                This was in addition to the Filey Brigg bird highlighted previously in this thread. This was a male trapped and ringed at Holland Haven this spring.

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                Martin Cade has been handling male Pied Flycatchers at Portland Bill Bird Observatory (Dorset) on an annual basis since 1989 and although there is marginal variation between the plumage of individuals, never has he seen anything like the Flamborough male in its appearance. The vast majority are just typical Collins text book. However, a wing chord of 83 would be fairly typical, although Svensson remarks that 83 would be at the top end. (page 227 and based on 189 measured samples) It would be a bird with anything over 86 that would kindle an interest.

                I am somewhat perturbed to see the claimed wing differences in these Pied Flycatchers, with Iberian Pied seemingly averaging much shorter than those of the shorter migrant Atlas Pied Fly. I would of expected to see Atlas Pied shortest, followed by Iberian, then the southern populations of Pied Fly, European Russian/Scandinavian Pieds and then White-collared Flys - but perhaps I am wrong in this thinking analogy. Guy Kirwan's comments are particularly interesting and perhaps demands a more consistent approach.

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                • Originally posted by MichaelF View Post
                  Seems a fairly safe assumption to me; there's no part of Britain to the north of Flamboro' (just lots of sea!), but it is a good landing / setting-off point for Scandinavia for any bird that had been drifted west of its normal route by the east winds at the time it turned up.
                  It's a lot less distance to 'drift' east from a British breeding area than it is to drift west across the North Sea. They do actually breed only about 20 km from Flamborough, on the North York Moors, so it could even have been dispersing from there (which would also explain a long stay before it got bored/lonely).

                  But, as the DNA showed, speculation is really pointless. A week ago it was speculated that it was a different species altogether, so no point trying to speculate which part of Europe its from. One guess is as good/bad as another, and there is no evidence to support any of them.

                  Lee, if you have a look at Lundberg and Alatalo's monograph, they highlight that variation in plumage is a key attribute of males. It relates to age and 'fitness'. On page 3, there's this pic showing how much forehead patch can vary.Click image for larger version

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                  • If ‘Pied Flycatchers’ (hypoleuca, sibirica, iberiae, speculigera) were to be split into 2 species based on morphology, the two species would surely be (hypoleuca + sibirica) and (iberiae + speculigera). Why does DNA tell a different story? To me, as a non-scientist, it seems that the bits of DNA which produce the differences in plumage can’t have been examined. But what about the bits of DNA that have been examined and show that speculigera is the odd one out, differing from the other 3 more than those 3 differ from each other? What aspects of the bird are these bits of DNA responsible for? Song & call, behaviour (including migratory behaviour) or are they just ‘junk’ DNA which doesn’t encode for anything? I am obviously just talking about nuclear DNA here. Mt DNA tells us (apart from which species the mother was) about evolutionary relationships, and for how long various populations have been separated. But I don’t see that length of separation necessarily correlates with how different these populations have become. This will depend largely on the environment and survival pressures, although I know there may well be differences brought about by ‘neutral’ genes, whose effects are neither advantageous nor disadvantageous.
                    Please feel free to tell me if I am talking nonsense here. These are just the thoughts of a layman.
                    Brett

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                    • Originally posted by Brett View Post
                      Why does DNA tell a different story?
                      Brett
                      Wow, there's a question Brett! It's a fair while since I studied any genetics and it was only undergraduate stuff but I'd be very interested in a basic explanation too. I know there's a poor correlation between morphology and genotype with often rather different-looking species having quite similar genotypes while often similar-looking species can show large genetic differences. Or if you like: physical appearances correlate poorly to genetic/evolutionary relationships. The increasing discovery of cryptic species is a testimony to this.

                      Quite why this is the case I don't really have a clue and the genetic link/causes to/of speciation would be interesting to hear about. As I understand it too, genetic differences reflect the time that taxa have been separated and this doesn't mean that the taxa have to have become clearly different in appearance, behaviour, ecology etc although they often do. I recall in Ian Newton's book that Eastern and Western Bonelli's are as different genetically from each other as they are from Wood Warbler and indeed any other subspecies analysed at the time he wrote the book. I was reading only yesterday how the Mag. Frigbirds in the Galapagos are being touted as a possible cryptic species genetically (and as an Evolutionary Significant Unit at worst) despite being to all intents and purposes identical to mainland birds. After for so long delimiting stuff using species concepts heavily loaded towards morphology, getting used to using genetics along with morphology etc is quite a change and seems bound to lead to perplexing (to our eyes at least) cases such as these Ficedula flycatchers.
                      Last edited by forktail; May 18th, 2012, 10:29 AM.
                      OBC John Peel Awesomeness
                      The little things they make me so happy, all I want to do is live by the sea...

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                      • Originally posted by alan lewis View Post
                        Agree with all of that (and didn't know about the sympatry in the Warbling Antbirds!). My view on claiming vagrants is a conservative one - if a number of taxa look more or less the same, its probably best to eliminate the most likely taxa, before you conclude that you could be watching one of the rarer ones. Ask Guernsey Dave.
                        cheers, alan
                        Totally agree, although GD has recently emerged from hiding with a Pallid Harrier under his belt that seems to have been identified in a more cautious fashion...

                        Originally posted by Brian S View Post
                        For those that have not yet read it, Martian Garner's blog
                        Martian Garner, the ‘final frontier’? That might explain that prodigious talent...


                        Originally posted by mafting View Post
                        Well, it's all relative, but a better way of saying it might be 'conclusive proof of genuine hybrids is very rare'. I know BWP et al are full of reports, but when I've followed up a few they've been far from convincing. I don't think descriptions are good enough for most, as this flycatcher neatly shows - without genetics, and 20 years ago, it could easily have been assigned to the hybrid category, and then it would appear in print in something like BB or BWP, and then it would become 'fact' and get cited for ever more.
                        I agree that proof is rare, but then most hybrid combinations won’t be detectable in the field, at the risk of reincarnating the last thread there were loads of cool examples of hybrids only detectable by invasive techniques that would never be noticed by field birders. Given the extensive evidence that hybridisation is a major driver of avian speciation then the phenomenon could we much commoner than we think... But I agree that understanding ‘variation’ is still key before invoking the H-word.
                        Dept. of Zoology, University of Cambridge, UK

                        My website - Neotropical Bird Club -Tropical Forest Research - Punkbirder - Wikiaves

                        In natural science the principles of truth ought to be confirmed by observation. — Carolus Linnaeus

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                        • Brett,

                          I found this paper http://rstb.royalsocietypublishing.o.../1841.full.pdf which deals with some of the questions you pose. Part 6 and the conclusion seem the most relevant. It closes with "In Ficedula flycatchers, traits causing pre- and postzygotic isolation are linked to the Z-chromosome, which is sheltered against interspecific introgression.
                          Speciation in Ficedula flycatchers hence appears to be, at least partly, driven by the evolution of sexlinked genes. One major future aim is to identify these genes."

                          F.
                          OBC John Peel Awesomeness
                          The little things they make me so happy, all I want to do is live by the sea...

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