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Scottish Crossbill - Yes? No? Never? (1 Viewer)
- Thread starter Gastronaut
- Start date
Farnboro John
Well-known member
I agree with the effect you report but not the reasoning. If one is confronted with a flock of mixed Crossbills and want a photo of Parrot Crossbill, then both for personal aesthetic and to avoid later dispute the selected individual is going to be the classic. This is not least because any birder is going to look at intermediates and go: "hm, not sure about this one, lets do the one with the really big bill that I am sure about". Their own certainty is an issue in selection.
This counts double or treble for winter Redpoll flocks when Arctics have been reported. A crowd of birders will agree almost exactly on the number of birds in the flock but have different opinions about how many Lesser/Common/Arctic Redpolls are present.
John
opisska
rabid twitcher
I lived in one for five years, nobody ever blinked an eye - local crossbills were all Common and sometimes we got some vagrant Parrots that we clearly different.
DMW
Well-known member
All clearly different apart from the ones that weren't and got overlooked as Common?
Andy Adcock
Worst person on Birdforum
My point is that if there is such overlap with Scottish, clearly, separation of these two is far from easy!
opisska
rabid twitcher
All clearly different apart from the ones that weren't and got overlooked as Common?
Well that's of course possible. If you have "Parrot Crossbills", do they associate internally in groups according to proportions? Because there were flocks and as far as I know, all members of the flocks were "big-billed" ones. But if they associate, they may have been whole overlooked flocks of course.
Xenospiza
Distracted
No. It's the combination of call and bill size that sets them apart.
I have seen plenty of cases where people made identification errors though.
There are crossbills with much more distinctive calls which do not provide visual clues... these are never thought of as separate species.
See also: Crossbill call types in the Palearctic – a birder’s perspective (Update eastern Palearctic call types, distribution areas and drivers of differentiation)
jurek
Well-known member
We agree that the bias exists, so the reason is maybe less important. What you describe is partially expectation bias: birders expect two separate species, so report only small and big birds.
I agree that Redpolls are similar situation: genetically identical species split into 3. And biases are similar: cherry picking publications proposing the split and ignoring ones against, waiting for an (unlikely) publication openly proposing the lumping etc.
BTW, anbody interested in bird taxonomy could be interested in thought fallacies and biases. Wikipedia gives an overview, although it sometimes falsely narrows biases to e.g. only medical or legal topics.
Selection bias - Wikipedia - picking publications for the split, and ignoring or diminishing papers against the split. Within a single new research like a genomic study: picking new differences, but ignoring new similarities.
Observer-expectancy effect - Wikipedia - tendency of birders to show discrete forms or characteristics (e.g. discrete sonogram shapes) if they expect different species
Reporting bias - Wikipedia - birders are not likely to report unidentifiable or intermediate birds.
Publication bias - Wikipedia and
Funding bias - Wikipedia - publication and funding are related to / variation of the reporting bias found in published papers: research proposing big differences is more likely to be funded, submitted and published than negative results,
Conflict of interest - Wikipedia - the result of the previous ones: researchers are rewarded with grants for discoveries like new species and publications. This can result in selection among the pool of researchers leaving only researchers proposing splits. Note that it is not necessary that even a single researcher, and not even a tiny bit unethically, changes his mind, or is influenced by grants. Simply only the ones which produce flashy papers remain.
Status quo bias - Wikipedia - waiting for a publication to suggest lumping, even if it is not likely due to the publication and funding bias.
Fallacies of definition - Wikipedia - changing what definition of a species to use. Here, the lack of genetic differences within crossbills and redpolls means single species under both classical biological and population species concepts.
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Gastronaut
_______________
Behave. I don't have that many ticks on my list that I can afford to lump all these.
How is it that whenever they rejig the classification they lump the ones I've seen and split the ones I haven't?
Tiraya
San Diego CA
Just because genetic similarity exists doesn't mean they hybridize. Is there evidence of parrot crossbill hybridizing with common crossbill, and do they overlap in breeding ranges? Also shhh, don't tell Americans that calls are not diagnostic in crossbills, it'll cause anarchy...!
Genetics are not the tried and true method for everything, and that shouldn't be the single nail in the coffin. I have no comments on Scottish crossbill though.
Genetics are not the tried and true method for everything, and that shouldn't be the single nail in the coffin. I have no comments on Scottish crossbill though.
Andy Adcock
Worst person on Birdforum
If they lumped the Crossbills and Redpolls, added to the recent IOC decisions, I'd have lost about ten birds!
pbjosh
missing the neotropics
On the contrary I would say you can mention it all you like, it may well just be ignored
Of all the Crossbills and Redpolls, Parrot Crossbill seems the most defensible by far and the one that I would want to see stronger evidence of hybridization before doubting too much. I personally don’t put much stock in Scottish or Cassia Crossbill as full species though the story of Cassia Crossbill is quite interesting. The redpolls I don’t have personal experience with but the papers make it all look exceedingly dubious. To me maintaining the redpoll split but lumping the juncos is very inconsistent.
jurek
Well-known member
My condolences for birders who lose too many species from their lists after the end of their over-splitting policy. Probably the BOURC needs to pay for emergency relief rarity twitches?
Next up the gulls...My condolences for birders who lose too many species from their lists after the end of their over-splitting policy. Probably the BOURC needs to pay for emergency relief rarity twitches?
Tiraya
San Diego CA
Lump herring gull, yellow-legged gull, Thayer's, Iceland, Vega, and Caspian into one species?? We'll call it..."Sea Gull".
Gastronaut
_______________
Do it!
Welsh Peregrine
Well-known member
Surely Kittiwake is “seagull”; the above complex are “see too often gull”!
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