Scottish Crossbill - Yes? No? Never? (3 Viewers)

[Farnboro John]

No opinion on the Scotsbill, but if you are interested in crossbill taxonomy, I would suggest looking for threads in the Bird Taxonomy forum. Quite a bit of discussion on this and related topics have occurred there.

The trouble is that the Crossbill enthusiasts expect everyone to accept their belief in a thousand separable, distinctive call types being meaningful identifiers of bird populations in an irruptive nomad, in a world where Great Tits and Chaffinches have distinctive dialects every few dozen miles in mixtures of residents and migrants where everyone knows they are single species. You'll get no sense out of those threads.

John

 

[Tiraya]

The trouble is that the Crossbill enthusiasts expect everyone to accept their belief in a thousand separable, distinctive call types being meaningful identifiers of bird populations in an irruptive nomad, in a world where Great Tits and Chaffinches have distinctive dialects every few dozen miles in mixtures of residents and migrants where everyone knows they are single species. You'll get no sense out of those threads.

John

In the US, they have more separation than I expected. It is not only call, but that the populations are fairly large, and said calls always correspond to a diet and breeding range. These nomadic flocks still tend to stick together. It's not a matter of dozens of miles with them, but more akin to hundreds...

I am not sure where I stand on the matter, only that in Europe, it seems to be messier even though there's less proposed species.

 

[wolfbirder]

Its a shame Lindsay Cargill (?) doesn't interact with birders any more, for his knowledge regards the existence of a distinctly separately-breeding Scottish type-Crossbill, is second to none, having handled/rung hundreds of such birds.

I don't think the exhibited updating research categorically rules out the existence of a Scottish Crossbill, but it just says more research is required. Their remark that this new N20-type call is the only call that 'might' identify a separate Scottish Crossbill population is not that new..........even I managed to record such a call at Boat of Garten woods when I went there two years ago, and was well aware that excitement type C calls were no longer defining, and I also managed to distinguish by ear, the difference between N20 of 'putative' Scotsbill and similar N2 and N15 calls of Common's. I don't believe this paper necessarily takes us any further backward or any further forward, to me it simply (and perhaps rightly) questions the original assignment of Scottish Crossbill as a full species, until further research is completed. Again, Lindsay, I think it is fair to say, was the man to go to. But he seems to have fallen out of birding altogether and hence with birding authorities too. From my recollection, he was clear that there was a distinct Scottish Crossbill type that bred separately from Common or Parrot and that could be assigned by call, or via bill depth and wing measurements in the hand, as well as by body size. He also remarked that with the 3 species, their moult was related to their breeding cycle, which was dependent on the food sources they were able to feed on. I recall him saying that in winter you get mixed flocks, but that they soon fragmented into their respective types, and that in his strong opinion, 'Scotsbill existed, but that it might not be exactly what we currently think it is'. He was adamant assortative breeding occurred.

I think there is little doubt that Parrot and Common occur, just as Arctic and Lesser Redpoll do, but its the middle bits that remain difficult to precisely define and distinguish. Even as far back at 2003, he suggested that 'the most likely candidate for a hybrid was a bird that gave Excitement call C.' Lindsay said a lot about Crossbills at the time, so to quote him for little bits here and there may misrepresent what he was trying to say about things. I think it is fair to say that although he was adamant that 3 species existed, he routinely acknowledged that further work was needed to determine what exactly defined them.

So, the newer N20 call may be just that..........but more work is required.

But of course, I genuinely don't know if Scotsbill (or Arctic Redpoll for that matter) should be given a full separate species assignment or maybe just a sub-species one, but at least morphologically there is clear distinction between Arctic, Common, and Lesser Redpoll, and critically for their full species status, even where they overlap they do not interbreed (other than very isolated instances) and that is why they are given full species status, as far as I understand. Perhaps species separation in Redpolls has not been for long enough for the required % DNA diversion, but this is why I feel the former can be more important than the latter at times (distinct selective breeding where populations overlap, rather than DNA % divergence).

I also personally favour separation on morphological differences, but then Northern Long Tailed Tit (ssp caudatus) are only classed as a sub-species because they overlap and interbreed in Denmark for instance. Should Masked Wagtail, which is a distinctly different morph, be a separate species? I guess White Wagtail was merged back because they interbreed with Pied.

So I guess, in simple terms, the key criterion separating full species from sub-species is defined primarily by geography? If populations overlap and they do not interbreed then they are afforded full status, but if populations do not overlap then they are classed as sub-species. Is this fundamentally correct? Sorry to be a simpleton.

 

[James Lowther]

So I guess, in simple terms, the key criterion separating full species from sub-species is defined primarily by geography? If populations overlap and they do not interbreed then they are afforded full status, but if populations do not overlap then they are classed as sub-species. Is this fundamentally correct?

Not really. If populations overlap and do not interbreed then that’s a good indication they are separate species as you say. But if similar taxa don’t overlap then in order to determine if they are best treated as separate species you need to examine other lines of evidence to determine if they are reproductively isolated I.e. if they WOULD interbreed given the chance. That’s obviously quite difficult but that’s the principle.
Cheers
James

 

[jurek]

I don't think the exhibited updating research categorically rules out the existence of a Scottish Crossbill, but it just says more research is required.

Hi, existence of Scottish Crossbill was disproven by genetic studies. Cheap large scale genomic sequencing is a method which was not available until the last decade.

this new N20-type call is the only call that 'might' identify a separate Scottish Crossbill population

excitement type C calls were no longer defining

I think this can be a valid discovery - that call types of crossbills appear and disappear fluidly. This would be similar to many other learned sounds produced by animals.

It seems that a library of crossbill calls has been collected over several decades in Britain. An interesting research would be to compare the full spectrum of calls recorded every year. The interpretation would be that different call types appear, spread and (presumably) disappear, not an constant elusive bird with a constant call which different studies found to be different.

Such call types could easily fool a researcher making a short-term study into claiming there are constant different populations, if the researcher chooses not to use genetic data.

 

[wolfbirder]

Hi, existence of Scottish Crossbill was disproven by genetic studies. Cheap large scale genomic sequencing is a method which was not available until the last decade.





I think this can be a valid discovery - that call types of crossbills appear and disappear fluidly. This would be similar to many other learned sounds produced by animals.

It seems that a library of crossbill calls has been collected over several decades in Britain. An interesting research would be to compare the full spectrum of calls recorded every year. The interpretation would be that different call types appear, spread and (presumably) disappear, not an constant elusive bird with a constant call which different studies found to be different.

Such call types could easily fool a researcher making a short-term study into claiming there are constant different populations, if the researcher chooses not to use genetic data.

Hi Jurek

I totally understand the point about DNA, and if one chooses that to be absolutely and finitely defining then so be it. I totally get why most would accept that.

I just think that assortative breeding is equally defining. It tells you that certain species recognise themselves as different. I'm not saying this is the case here, though I suspect Lindsay Cargill certainly would, I'm just making the general point that whilst genetic study is an extremely valuable tool to identification, maybe separation has occurred in relative recent times.

 

[opisska]

So when interracial marriage was taboo, homo sapiens was actually several species?

 

[Phil Andrews]

A (in)famous British birder advocated "at least 10 species of human" a few years back.

 

[opisska]

Five species in India alone when the caste system was in full power?

 

[edhunter]

interesting thread this at times like a Viz cartoon,, seems not to grasp at all the vocal types of Crossbills and the already published stuff as if its not even been deeply considered or researched at all.

Crossbills do in the Uk suffer from lack of effort regarding sound recording ...its likely due I would think to the uncertainty of Scot bill everyone has switched off and the lack of sound recording effort made is as birding culture here not just for xbills . To read a very good comparison to Calls - FC and EC avesrares this works, the Scot bills I recorded 2 years ago fit very well to this ( no ecs recorded). If you get Fcs or ecs which do not match on anything email me or them.

One big problem with Crossbills is everyone is not sharing the data and the publications are late after writing.... too publication or some choose to to do this at ten year intervals which stops progress for other Crossbill folk then you at end . the birders ..think its all BS by the looks of this thread above

"Crossbill research would make an interesting study of bad practices in science. Notorious is cherry-picking arguments and publications for versus against the split. Another is selection bias. 20. century ringing manuals report many intermediate individual crossbills, but 21. century birder records and photos show almost exclusively classic Common and classic Parrot Crossbills. Intermediates are selectively not reported."

Harsh comments with no idea of the current reality of Crossbill knowledge , myself I do not bother to put out vagrant crossbill types as the last years have shown since if you cannot tick it ....noone is interested, but since "flava wags " is the trend ( not much difference here regarding call separation.....although Crossbill vocal types is far easily separable) hopefully this will change in the future

There was a very interesting influx of crossbills this autumn winter involving birds from way east. In October in Wales we got some 3 N9s previously around 4 Uk ( coincided to birds near Paris and Germany) records , these came in same group as multiple N5s again first Welsh records just 3 in uk - all from way east. These initially arrived with N8....east( rare in Wales) more regular in England, also some N3s again a very rare Welsh one with previously just 6 occurences ( a central Europe type)

The birds that followed after the autumn much anticipated (to the similar " sibe acc " winds) are far more interesting and happened with major Coal tit irruptions also in Scan. Viz mig ( Low numbers) Crossbills irrupted as far as Wales for several weeks after that even when Thrushes dried up. They all have disappeared in the last week ...these were particularly interesting in many ways. Maybe someone reading this has recordings to add to the picture??? They just left Wales....maybe back nin England soon., Hope so ...they did not just miss England. please contact me if you have such recordings

This post just to open your eyes to that Crossbill folk ...who are as rare as these birds in the uk.... are still at it and certainly not blinkered and certainly not cherry picking we are trying to work out these birds vocally -

Scot xbill wise the Welsh N15 does not impact identification from recordings

all the best
Ed

 

[wolfbirder]

I learnt how to recognise N20 calls and sono-grammed them in Boat of Garten Woods, Speyside in 2021, quite distinctive I thought though it took 3 weeks of listening to them prior. Also saw what were clearly Commons, and others near Grantown on Spey that were clearly Parrots.

Also had 4 large billed Crossbills near Bridgnorth, Shropshire issuing N6 calls in December 2020.

I did a report of what I saw on Speyside which was reported here: -

A return to Scotland to try to see Scottish Crossbills

I spent a superb four nights in Speyside at the end of April, based at Grantown On Spey, ultimately seeing nearly all my targets including 3 Capers, 16 Black Grouse, 3 White-billed Divers, American White-winged Scoter, 7 Parrot Crossbills, and 3 'putative' Scottish Crossbills. I say 'putative'...

www.birdforum.net

 

[jurek]

Harsh comments with no idea of the current reality of Crossbill knowledge , myself I do not bother to put out vagrant crossbill types as the last years have shown since if you cannot tick it ....noone is interested,

You confirmed exactly one of the reasons of the criticism. If out-of-place records are selectively not reported, how one can trust the pattern?

This seems to be the bias in the community, for which individual birders have little influence - but this does not make the bias real. I commented before that a science result can be fake without any single person being dishonest - simply by selective reporting / verification.

 

[01101001]

Harsh comments with no idea of the current reality of Crossbill knowledge , myself I do not bother to put out vagrant crossbill types as the last years have shown since if you cannot tick it ....noone is interested, but since "flava wags " is the trend ( not much difference here regarding call separation.....although Crossbill vocal types is far easily separable) hopefully this will change in the future

Yes, you can tick them, but only 'A', 'B', 'C', 'D', 'E', 'F' and 'X' types (as per the original The Sound Approach classification):

Sign in

ebird.org

EDIT: Not sure how it translates to the 'N' system: maybe you know or it's written somewhere in the internet?

EDIT 2: Not much overlap, it turns out (from the link above: avesrares).

 

[01101001]

Apart from those already mentioned at avesrares:

• B (Bohemian) 🔊 = N1,
• C (Glip) 🔊 = N4,
• D (Phantom) 🔊 = N7,
• X (Parakeet) 🔊 = N8,

it also looks like the following could be true:

• A (Wandering) 🔊 = N3,
• E (British*) 🔊 = N6,
• F (Scarce) 🔊 = N13.

(I based my assumptions on 'Similar FCs', 'Similar ECs' and 'Distribution' sections from avesrares, plus Part 8: Twitching and taxonomy - The Sound Approach.)

@edhunter Please check the last three lines for obvious mistakes or overinterpretations.

EDIT: *for which eBird mistakenly uses the name 'Parakeet' for the second time

EDIT 2: Unfortunately, crossbills are thin on the ground where I live; anyway--in case I managed to catch up with one--do the authors of the blog post still accept submissions of new recordings to their database?

EDIT 3: Also (some of those most probably have innacurate data):

• Altai 🔊 = N9,
• Corsican 🔊 = S2*,
• Tien Shan 🔊 = E1,
• Himalayan 🔊 = E2,
• Japanese 🔊 = E3,
• Dalat 🔊 = E5;

potential call types:

• Cyprus 🔊 = S3,
• North African 🔊 = S6,
• Balearic 🔊 = S22.

*the English version of this description is farther above

Index of all call types described in the article: avesrares. (Just in case, everything in my post and both articles above concerns the Palearctic only.)