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Crossbills (1 Viewer)

But Lindsay's clear point "It is now fairly evident that many of the birds that DNT and Alan Knox referred to as "Scottish Crossbill" are in fact what we today call "Parrot Crossbill" here in Scotland" — the really thick-billed birds one sees in Scotland are not, and never have been, "Scottish Crossbills". I've not seen Hartert's specimen either, but it obviously needs re-examination in light of the new data.

Michael ( it is Michael, right ? ;) ) the caveat I used is "many" ! Alan (and possibly Desmond) also miscategorised some Commons as "Scottish" which just shows how important physical evidence (Biometrics and Calls) are in making a classification. The fact that it was assumed scotica was biometrically intermediate is what has caused this. However, there are 'intermediate' crossbills in Scotland.

On the comments about "Scottish" being a type of Common Crossbill, it is certainly possible, however it would be unusual in that putative scotica is sedentary unlike other curvirostra that are only present for a few months and then move away - Marquiss and Rae showed this with ringing data of birds trapped in Deeside. On the other hand, birds that have been ringed and biometrically classified as scotica (and my case sound recorded !) have been retrapped years later. In my case, I have physically retrapped two scotica type birds at exactly the same site 4 years apart - one of them with Dr. Ron Summers, details here:

http://pinemuncher.blogspot.co.uk/2010/07/catching-pine-crossbills-upper-deeside.html

I also have re-sighting data from colour-ringed birds.

So, if what we currently classify as scotica is a Common type it would be unique in that it is sedentary, and indeed it would appear to be endemic.....you can see where I am going with this !

Regarding Parrot Crossbills colonising from continental Europe it is certainly possible. However, no Scottish birds that have been ringed have turned up anywhere else (including England !). Also, why did all these birds that turned up two winters ago down south not colonise, surely there is sufficient habitat ? The Norfolk birds in the 80's actually bred successfully, so again why was a viable population not established ? My understanding from collected evidence is that continental crossbills (both Parrot and Common) will irrupt, possibly breed and then move. My theory is that the population of large billed crossbills in Scotland, "Scottish Parrot Crossbill", have been there for a very, very long time. To perhaps highlight the sedentary nature of 'Scottish Parrot' I saw a colour ringed Parrot in Glen Derry in 2005. I reported it to Robert Rae who informed me it was ringed at that very location.......in 1986.

The 'Scottish' type call that was recorded in Kielder Forest that Nutcracker keeps mentioning I would very much like to see/hear that. I reckon it would take all of several seconds to shoot it down. ;)

John, there are variations in crossbill calls within a 'type' that may similar to the dialectic variation in Great Tits and Chaffinches that you keep going on about. However, the differences between actual call types would be similar to that of a Great Tit to a Coal Tit. If you want to send me examples of this dialectic variation, or point me to recordings that you think exhibit it, I will gladly produce sonograms of the supposed variations. It is too simplistic and naïve to assume that all variation in crossbill calls is merely dialectic, though it may explain subtle variations within the call types.


Lindsay
 
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Crossbill recordings

Dear Birdforum members,

for a PhD on the biogeography and maintenance of call types in the Palearctic crossbills I am looking for sound recordings of Common, Parrot, Two-barred and Scottish Crossbill (Loxia curvirostra, L. pytyopsittacus, L. bifasciata & L. scotica).
Of interest are recordings of all species from all over the Palearctic. Very old recordings are as useful as the ones you might take in the upcoming months.
I would greatly appreciate any help, be it in form of recordings or hints towards private or public sound archives.
Thank you very much in advance for your support!
My mail address is: [email protected]

All the best,
Ralph Martin
 
I could supply sound recordings of the population of Crossbills from ETNA volcano, in Sicily. Very interesting and un-named population, with huge bill and plumage colour like N African birds
 
Thomas L. Parchman, C. Alex Buerkle, Víctor Soria-Carrasco, Craig W. Benkman. Genome divergence and diversification within a geographic mosaic of coevolution. Molecular Ecology, Early View Article.

abstract
 
I was reading through the TOC for the December volume of The American Naturalist this morning, and found this paper. While it is not taxonomic in a strict sense, it does add to the saga of the South Hills Crossbill, and also notes that it is a taxon that is on a course for vanishing due to changes in climate.

The Natural History of the South Hills Crossbill in Relation to Its Impending Extinction
http://www.journals.uchicago.edu/doi/abs/10.1086/688904
 
Thomas L. Parchman, C. Alex Buerkle, Víctor Soria-Carrasco, Craig W. Benkman. Genome divergence and diversification within a geographic mosaic of coevolution. Molecular Ecology, Early View Article.
Now published: Mol Ecol 25(22):5705–5718.

Also in the same issue:

Thompson. 2016. News and views, perspectives: Coevolution, local adaptation and ecological speciation. Mol Ecol 25(22):5608–5610.
[free access]
 
Western Palearctic

Parchman T.L., Edelaar P., Uckele K., Mezquida E.T., Alonso D., Jahner J.P., Summers R.W. & Benkman C.W., in press. Resource stability and geographic isolation are associated with genome divergence in Western Palearctic crossbills. J. Evol. Biol.

There
 
Future split of North African and Balearic crossbills?

Parchman T.L., Edelaar P., Uckele K., Mezquida E.T., Alonso D., Jahner J.P., Summers R.W. & Benkman C.W., in press. Resource stability and geographic isolation are associated with genome divergence in Western Palearctic crossbills. J. Evol. Biol.

There


I am surprised that there is no mention here of any future splits based on this study. The divergence of poliogyna and balearica from the Common Crossbill are even greater than the divergence between the Parrot and Common crossbills.

I have one question, why there is no mention of Scottish Crossbill (Loxia scotica) whatsoever in the text (apart from the references!)?. Especially, what this means?

The authors wrote “…nine of the curvirostra sampled from Scotland represented two different vocal types (vocal types C and E of Robb, 2000; or 1A and 4E of Summers et al., 2002)”. A quick scan of Robb’s article I can see that these two types are different from what is known as the Scottish Crossbill. Any idea much will be much appreciated.

Feel free to check my blog about this article at MaghrebOrnitho.
 
I have one question, why there is no mention of Scottish Crossbill (Loxia scotica) whatsoever in the text (apart from the references!)?. Especially, what this means?
I guess they didn't want to mention anything so controversial as a "species" that is at best, unprovable, and at worst, doesn't exist 8-P
 
It cannot be denied that polyogyna and balearica form clear monophyletic clusters but, on the other hand, there is no clear evidence of reciprocal monophyly with curvirostra (see Fig. 3).

I'd tend to read it the other way around -- it's quite remarkable that the divergence between pytyopsittacus and nominate curvirostra is so small, not to say nonexistent, even smaller that the divergence between nominate curvirostra and several populations usually ascribed to this species. (And thus it may be surprising that no one is at least discussing the possibility of a lump. The authors suggest that islands of differentiation "likely exist given substantial bill and body size divergence between curvirostra and pytyopsittacus, but are difficult to detect". But does it need to be the case...? After all, the morphological divergence is arguably merely quantitative, and the characters involved are known to have a great potential of adaptive variation in the group and presumably have a polygenic basis [thus may not be represented in the genome by any unique gene around which an island of differentiation would be susceptible to appear easily].)

It would have been great to have an American plain-winged bird included in the tree. (Couldn't the draft genome of sinesciuris, which is said in the paper to have been assembled as a reference for alignment, have provided enough data to play this role ?)
 
It cannot be denied that polyogyna and balearica form clear monophyletic clusters but, on the other hand, there is no clear evidence of reciprocal monophyly with curvirostra (see Fig. 3).

I'd tend to read it the other way around -- it's quite remarkable that the divergence between pytyopsittacus and nominate curvirostra is so small, not to say nonexistent, even smaller that the divergence between nominate curvirostra and several populations usually ascribed to this species. (And thus it may be surprising that no one is at least discussing the possibility of a lump. The authors suggest that islands of differentiation "likely exist given substantial bill and body size divergence between curvirostra and pytyopsittacus, but are difficult to detect". But does it need to be the case...? After all, the morphological divergence is arguably merely quantitative, and the characters involved are known to have a great potential of adaptive variation in the group and presumably have a polygenic basis [thus may not be represented in the genome by any unique gene around which an island of differentiation would be susceptible to appear easily].)

It would have been great to have an American plain-winged bird included in the tree. (Couldn't the draft genome of sinesciuris, which is said in the paper to have been assembled as a reference for alignment, have provided enough data to play this role ?)
Thanks Laurent! I agree about the lack of discussion about the possibility of lumping. Is it because we are in the “age of splitting”? There aren’t many well-known examples of ‘established’ species lumped during the last few years (off the top of your head, I am think about the Barbary Falcon, any others?). Whereas cases like Common Crossbill are known (e.g. Horned Lark, there is neither splitting of the species into six or at least splitting elwesi/longirostris, nor lumping of bilopha.
 
Something which interest me is correlation of head/bill size and voice. These are treated as independent characters supporting each other in identification. Is it possible that the call difference is mostly a mechanical result of size of bill, musculature and head? A bigger pipe will sound a lower tune?

Another topic is genetic/environmental component of bill size. It is usually assumed to be purely genetic. However, there must be an environmental component: lifetime difficulty in processing food should influence the size of kerating bill covering and muscles.
 
Whereas cases like Common Crossbill are known (e.g. Horned Lark, there is neither splitting of the species into six or at least splitting elwesi/longirostris, nor lumping of bilopha.
That's just awaiting DNA samples for some of the less easily accesed central Asian subspecies - the particular problem is that the oldest (first-named) central Asian ssp is unsampled, and would be important in determining the valid name of split species.
 
New name for Loxia sinesciuris

Here's one of the more interesting nomenclatural proposals I've come across in a while. The authors argue that the name Loxia sinesciuris is invalid because "sinesciuris" is a prepositional phrase, a grammatical form not permitted for use as a species name under ICZN rules. They propose the new name "Loxia sciurinimica", while at the same time arguing that it shouldn't be adopted!

The name is published in a note in the American Birding Association Birder's Guide to Listing and Taxonomy. I'm not sure if it's possible to link to the article directly, but it's on page 40 of the entire issue available here.
 

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