Crossbills (2 Viewers)

[Jacana]

Geoffrey Hill who submitted the failed proposal to lump last year. I wouldn't necessarily take him as an expert, since while he has published on them, as far as I can tell this is a review paper and he hasn't necessarily done the in-field work that folks like Benkman and co do.

Yep, I'd put him as a speciation expert though and his contributions to the speciation process and his thoughts on species concepts are worth listening to, even if I don't necessarily agree with all his lines of reasoning.

 

[Mysticete]

Yep, I'd put him as a speciation expert though and his contributions to the speciation process and his thoughts on species concepts are worth listening to, even if I don't necessarily agree with all his lines of reasoning.

Well I should say crossbill expert. He has done work on speciation in general and did publish his species concept.

 

[jurek]

Scottish Birds article here: https://www.the-soc.org.uk/files/docs/bird-recording/sbrc/sbrc-position-on-scottish-crossbill.pdf

It is a textbook example of bias in science: we believe there exist a different crossbill species and we are looking for differences proving it. Wow!

Confirmation bias - Wikipedia

en.wikipedia.org

 

[l_raty]

Scottish Birds article here: https://www.the-soc.org.uk/files/docs/bird-recording/sbrc/sbrc-position-on-scottish-crossbill.pdf

It's interesting that they suggest "fluent temporal transition" between quite distinct call types in a matter of two decades...

 

[Farnboro John]

It's interesting that they suggest "fluent temporal transition" between quite distinct call types in a matter of two decades...

If genuine then surely it means there's no such thing as a call type in any meaningful fixed way: just the current vogue in part of the overall Crossbill population?

John

 

[THE_FERN]

If genuine then surely it means there's no such thing as a call type in any meaningful fixed way: just the current vogue in part of the overall Crossbill population?

John

y; but also, is there ever a fixed anything?

Everything changes—you can't step into the same river twice—on different timescales. Organisms change both by evolution (change in frequency of alleles) or by changes in behaviour.

 

[jalid]

One plausible hypothesis for avian vocal dialect development is that they develop as a by-product of dispersal and vocal learning by mimicking other individuals, without real function. But very probably there is no such general explanation for dialect formation which fits to every case and species. Crossbills, for example. It seems to me that for crossbills themselves the call types are very meaningful. But fixed they are not. The history of sound recording is still quite short and more surprises are to come - for other species too.

 

[Mark Lew1s]

It is a textbook example of bias in science: we believe there exist a different crossbill species and we are looking for differences proving it. Wow!

Confirmation bias - Wikipedia

en.wikipedia.org

Utter nonsense. As one of the authors of the note, I can assure you that I don’t believe there is a different species of crossbill in Scotland…

 

[Mark Lew1s]

It's interesting that they suggest "fluent temporal transition" between quite distinct call types in a matter of two decades...

First noted here by Ron Summers - who saw changes in ‘Scottish Crossbill’ calls in less than a couple of decades Calls of crossbills in Scotland: association with bird size and changes over time

 

[Kirk Roth]

Utter nonsense. As one of the authors of the note, I can assure you that I don’t believe there is a different species of crossbill in Scotland…

I think the language of the note is such that it can be "gleaned" that there is skepticism from the authors that the Scottish is a valid taxon, but there is also the bit about it being the only endemic bird species. And some readers are seeking a stronger "repudiation" (really they are looking for something that will spawn "official" taxonomic change).

Not that this relates to any fault of the authors - this note is both useful and a very difficult line to walk while publishing something at large. I agree that judgements should be withheld and I welcome the broad dissemination of local expertise such as this - as delicate as the process may be.

 

[Xenospiza]

It's interesting that they suggest "fluent temporal transition" between quite distinct call types in a matter of two decades...

It is still interesting that there was AND is a call type that appears restricted to Scotland.
But this is the place to go for a perspective on crossbill calls:

Crossbill call types in the Palearctic – a birder’s perspective (Update eastern Palearctic call types, distribution areas and drivers of differentiation)

Julien Rochefort & Ralph Martin Ceci est la version anglaise de l’article. Cliquez ici pour lire la version française To jump directly to the call type index, click here To enter data int…

avesrares.wordpress.com

 

[jurek]

Utter nonsense. As one of the authors of the note, I can assure you that I don’t believe there is a different species of crossbill in Scotland…

Sorry for this. The wording of the article: "SBRC is no longer aware of any plumage, biometric, vocal or genetic criteria that can be used to identify Scottish Crossbill with confidence. As a result, SBRC will no longer consider any records of the species. "
seems to suggest the opinion that the Scottish Crossbill is still a species, but without any differences. This upside-down reasoning is perhaps because of referring to previous articles which strongly believed the Scottish Crossbill exists.

The idea that Common Crossbills form dialects of birds foraging together, which change, appear and disappear within the time of a decade or few decades, seems intuitively sensible. It would explain the situation. I noticed that "vocal dialects" were not objectively defined and fully re-found by different researchers, and suspected some subjectivity / seeing non-existing patterns. But if dialects objectively change fast this would also explain the situation.

BTW, with the current trend "put AI into everything" it would be interesting to put a stream of unedited crossbill calls into the AI and see whether the AI finds and separates call types and subtypes.

 

[Peter Kovalik]

Martin, R., Rochefort, J., Mundry, R. and Segelbacher, G. (2023) Fast cultural evolution of Crossbill (Loxia spp.) calls in the Palearctic. Ibis, first published 4 July 2023
https://doi.org/10.1111/ibi.13253

Abstract
Learned vocal signals of birds provide one of the most comprehensive sources of evidence for culture in animals. Such vocal signals often vary spatially and temporally. Signal variation can be driven by direct factors such as cultural drift and selection or by indirect factors such as changes in the environment, which may affect morphology and therefore acoustic capability. In this study we analysed flight and excitement calls of several call types of the Red Crossbill Loxia curvirostra and other crossbill species. Calls were recorded between 1962 and 2019 across the Palearctic region. We measured acoustic similarity within flight and excitement calls and modelled the size of the effect attributed to temporal and geographical distance. Geographic distance between different sampling locations explained less call variation compared to temporal distance, and temporal variation within the excitement calls was smaller than in the flight calls. We conclude that calls of most call types of Red, Scottish, and Parrot Crossbill are an example of cultural evolution. We suggest that excitement calls are less modifiable because they can serve better in dangerous situations when they are stable in time and space. In addition, we found no support for increasing or decreasing flight call similarity of call types while or after being in contact as in another study from North America. The reasons for the cultural evolution in calls of Palearctic crossbills remain unclear.

 

[jurek]

The reasons for the cultural evolution in calls of Palearctic crossbills remain unclear.

Maybe bird memory is not perfect?

It would be interesting to compare recordings of other birds which have learned calls from the past and now. Maybe other learned bird call "drift" over time, too?