Brown Booby may get split - an issue for British listers? (1 Viewer)

[Andy Adcock]

Following the announcement of the potential split of Brown Booby in to two species, does this mean that birds in the UK will have the dreaded 'sp' alongside their name or are they separable in the field?

 

[Phil Andrews]

Following the announcement of the potential split of Brown Booby in to two species, does this mean that birds in the UK will have the dreaded 'sp' alongside their name or are they separable in the field?

Have you got a link Andy? Is one far more likely to occur in British waters?

 

[Andy Adcock]

2024 Proposals - American Ornithological Society

Proposals 2024-A (PDF) 2024-A-1: Reconsider the generic placements of Haplospiza rustica and Acanthidops bairdi 2024-A-2a: Make changes to our classification of the herons (Ardeidae): Modify the linear sequence and existing taxonomic structure within the family 2024-A-2b: Make changes to our...

americanornithology.org

Second top of the second block

 

[DMW]

Have you got a link Andy? Is one far more likely to occur in British waters?

Yes, the nominate by several orders of magnitude I would assume?

 

[Andy Adcock]

Yes, the nominate by several orders of magnitude I would assume?

Not sure it works like that does it?

Recent splits e.g Subalpine Warbler, Olivaceous Warbler, B-e Wheatear etc are evidence?

 

[DMW]

Not sure it works like that does it?

Recent splits e.g Subalpine Warbler, Olivaceous Warbler, B-e Wheatear etc are evidence?

Not that I'm any kind of expert, but at least some of the photos I've seen would appear to confirm the nominate based on darker head and neck than the rest of the upper parts, to the extent that's diagnostic.

 

[Bismarck Honeyeater]

There’s just one record claimed outside of the Pacific, it’s probably not one for us to have worry about.

 

[Andy Adcock]

There’s just one record claimed outside of the Pacific, it’s probably not one for us to have worry about.

I know, but for the purposes of the British list, unless you confirmed the specific ID it would appear on the national list as 'sp' surely?

 

[Mysticete]

I don't know why folks wouldn't treat these records as the Atlantic form. The Cocos/Brewster's form would be an order of magnitude rarer. Certainly the burden of proof is on the folks who think could be the Cocos/Brewster's form, to demonstrate it is that. Certainly the default mentality for most birders is to focus on the likely option, and only turn to rarer birds as an ID if features or characteristics pop up that cause you to question the initial ID.

As an example, when I am out birding in Wisconsin, and I see an accipiter fly through, I focus on Coopers (the most likely option), Sharp-shinned, and Northern Goshawk. I don't start running through Gundlach's, Eurasian Sparrowhawk, Eurasian Goshawk, etc, even though some of those COULD potentially show up as an incredibly rare vagrant.

Personally I would be more worried about Japanese vs American Pipit as an ID challenge, although I would guess that is more a split on people's radar.

 

[Phil Andrews]

Also of course this proposal is from the AOS rather than the IOC.

 

[Steve Lister]

Personally I would be more worried about Japanese vs American Pipit as an ID challenge, although I would guess that is more a split on people's radar.

An excellent analysis of their separation in the current issue of British Birds, suggesting most will be 'doable'.

 

[DMW]

I don't know why folks wouldn't treat these records as the Atlantic form. The Cocos/Brewster's form would be an order of magnitude rarer. Certainly the burden of proof is on the folks who think could be the Cocos/Brewster's form, to demonstrate it is that. Certainly the default mentality for most birders is to focus on the likely option, and only turn to rarer birds as an ID if features or characteristics pop up that cause you to question the initial ID.

As an example, when I am out birding in Wisconsin, and I see an accipiter fly through, I focus on Coopers (the most likely option), Sharp-shinned, and Northern Goshawk. I don't start running through Gundlach's, Eurasian Sparrowhawk, Eurasian Goshawk, etc, even though some of those COULD potentially show up as an incredibly rare vagrant.

Personally I would be more worried about Japanese vs American Pipit as an ID challenge, although I would guess that is more a split on people's radar.

I don't think it's quite comparable. Unlike Cooper's Hawk in Wisconsin Brown Booby is still a recent vagrant to the British Isles, and Andy's point is a fair one. It's worth remembering that a moribund Ascension Frigatebird found in Scotland in the 1950s was assumed to be a (seemingly much more likely) Magnificent until the specimen was re-examined.
I suppose it's somewhat analogous to Campbell Island Albatross: do you reject any record of Black-browed without photos of the eye, or take the pragmatic approach?

 

[Andy Adcock]

In a great many places these days, birders will happily tick on range but when it comes to the national list, the keeprs of that list, must be more demanding I think?

 

[Farnboro John]

In a great many places these days, birders will happily tick on range but when it comes to the national list, the keeprs of that list, must be more demanding I think?

Still waiting for the Arctic Warbler review though.... Since some of our transatlantic friends have said its not a difficult ID Brown Booby is probably no problem and in any case one would hope someone submitting a first would have taken the ID to subspecies as a matter of course. Once the first is past who cares what BOURC thinks about subsequent ones?

John

 

[Andy Adcock]

Still waiting for the Arctic Warbler review though.... Since some of our transatlantic friends have said its not a difficult ID Brown Booby is probably no problem and in any case one would hope someone submitting a first would have taken the ID to subspecies as a matter of course. Once the first is past who cares what BOURC thinks about subsequent ones?

John

What if say the 3rd record was new to a particular birder and wasn't specifically ID'd? It seems unsatisfactory and a bit unscientific to assume that every individual is the same species just because one has been proven, they don't take that approach with e.g Subalpine Warbler?

 

[Farnboro John]

It seems a bit unscientific to assume that every individual is the same species just because one has been proven, they don't take that approach with e.g Subalpine Warbler?

I didn't say BBRC wouldn't care but BOURC will not have an input after the first. Tbh all birders make that kind of decision every day: do you check that all Swallows aren't the American subspecies?

John

 

[dantheman]

The analogy should be with 2 rarities surely (as already mentioned), one considerably rarer than the other ... eg Red-breated and Taiga Flycatcher?? Can be checked, generally, but not always?

Seabirds are known to wander, so can't be ruled out.

But surely pragmatism should rule - if there are potentially dozens of the commoner rarity in the vicinity, and an unknown (and unknowable) slim possibility of a species from a completely different region then you stick with the default as on the balance of probabilities ... ?

 

[Andy Adcock]

I didn't say BBRC wouldn't care but BOURC will not have an input after the first. Tbh all birders make that kind of decision every day: do you check that all Swallows aren't the American subspecies?

John

But that isn't a full species so not a valid comparison, if they were to be split, people would take more notice.

 

[Andy Adcock]

The analogy should be with 2 rarities surely (as already mentioned), one considerably rarer than the other ... eg Red-breated and Taiga Flycatcher?? Can be checked, generally, but not always?

Seabirds are known to wander, so can't be ruled out.

But surely pragmatism should rule - if there are potentially dozens of the commoner rarity in the vicinity, and an unknown (and unknowable) slim possibility of a species from a completely different region then you stick with the default as on the balance of probabilities ... ?

So my example of Subalpine Warbler, if you needed it but you'd seen one that wasn't specifically ID'd, you'd tick it on the basis that one was commoner than the other?

The Soft-plumaged Petrels may be a better comparison, what do people do with them?

 

[Farnboro John]

But that isn't a full species so not a valid comparison, if they were to be split, people would take more notice.

Brown Booby has only just been split (or is still in the process - it's not in IOC 14.1?) - just the same really.

And most people wouldn't take more notice of Swallows (or anything in a similar position) except in a very few specific circumstances like hot vagrancy site just after transatlantic storm during migration. Not spring at Acres Down with the odd Swallow passing Northwards.

John