New unified list of birds - Avilist (7 Viewers)

[Andy Adcock]

If support for something is marginally above what is necessary to have it accepted, chances are that it will be below that threshold in one of the checklists. I agree it's far from optimal, though, and if the dissenting votes are equally scattered over the voting panels, something could be accepted despite significant dissent... But it's better than nothing.

To be frank, I'm actually far from convinced that voting can ever be an acceptable way to deal with a scientific question.

I agree but what's the option?

 

[l_raty]

I thought this was exactly what Tobias was about, or have I got the wrong end of the stick - different assessment criteria for different groups of birds.

Can you clarify?

The criticism that I have most often seen is that, although the system may appear to bring some objectivity into the decisions, the scoring is actually largely arbitrary and poorly reproducible, hence the outcome is in fact not objective at all.

E.g., see the comments in the Anas crecca / Anas carolinensis NACC proposal here (pp. 22-23), where Kevin Winker explains that two different outcomes were reached by changing the scoring of one plumage character.

 

[Jon.Bryant]

I actually think no one other than Birdlife does, and in fact thanks to Avilist they probably don't either

Sorry, my misquote... BirdLife actually states

'The BirdLife Taxonomic Working Group (BTWG) makes decisions on revisions to the Checklist, based on recent taxonomic research and where necessary the use of systematic criteria by which species rank can be consistently assessed (Tobias et al. 2010). These criteria weight morphological and acoustic differences between taxa and have been found to perform strongly when compared to other taxonomic approaches (Tobias et al. 2021).

Where necessary, presumably means where other methods fall down, through lack of data?

 

[Frank van Drogen]

To be frank, I'm actually far from convinced that voting can ever be an acceptable way to deal with a scientific question.

I am Frank too

I fully agree, voting isn't a way to answer a scientific question. But I guess both taxonomists and listers detest having an 'inconclusive data, it can't be determined whether this is a species or subspecies until further research is done' clauses.

As a geneticist I have a pretty clear point of view of how I would determine a species, but I am around long enough to realize that grey zones will always remain (and nobody is willing to fund full genome sequencing and analysis of a significant number of individuals of all disputed species).

 

[Kirk Roth]

Unfortunately it is true that taxonomy is not an 'absolute' science. If it was not, why the need of a committee - we would simply need to apply a set of rules and have a simple check of the results by a reviewer.

I feel that the last three pages illustrate the need to emphasize that taxonomy isn’t ANY kind of science. In ornithology, we use science to inform our taxonomy, which is only an organization system.

The Tobias system was an attempt to make that organization systematic, objective, uniform, and criterion based… which are all characteristics that science has. But as has been pointed out, there are still subjective criteria. As I want to point out, there is practically no way to test hypotheses, illustrate significant difference, etc. in what is essentially a naming system after all. We can do science with things like genes and investigating their differences, or with any of various phenotypic traits. But stating which of those differences makes a category or not - this is absolutely not an issue of hypothesis testing and all to do with naming and structuring.

Or to take the inverse perspective - let’s imagine that we are investigating “taxonology.” This would mean running some sort of experiment in which we can test a single parameter to measure (somehow) the categorization. So for example, if we define a “good” taxon as one that is “not confusing” and present different systems of Eurasian/Green-winged Teal taxonomies to scientists or birders (in statistically robust numbers of course), then measure confusion with some proven test to decide whether it should be split. If we define a “good” taxon as having a certain genetic difference - well, do we simply deal with gulls and ducks measured the same way as owls and warblers (regardless of any other differences/similarities), or do we need a different taxonomy for each… and how do we “test” those? Or we could dive into Tobias groundwork and test which criteria produce categories that produce whichever (desired?) result of categorization… but we first need to somehow find an objective and testable way of defining what “makes” a category. How does one measure and test the difference between behavioral, physical and genetic difference against one another, alongside communication needs, past and present usage, and any number of other variables which relate to how we organize things? Do we first need to study what factors humans use to categorize birds… in some sort of controlled unbiased island devoid of influence from Clements, IOC, and Birdlife? If its found that the most important thing is what color and size the bird is and genetic relationship be damned, is that really the kind of communication we want?

Subjectively, this is very easy - we just decide. Objectively - nearly impossible to compare these apples with those oranges and pretend it is not violating basic principles of scientific method. Needless to say, we don’t engage in this absurdity for every species, genus, family, and so on - we subjectively decide.

Taxonomy is a system of word use - in a sense it is a language. Beyond “describing what is used and what isn’t” I don’t believe there is much room for objective truth without introducing pretense. And I believe that’s okay, as long as we aren’t pretending it is something it isn’t.

 

[johnallcock]

NO......that's my point. I know people that have experimented with the calls and they do not respond so won't recognise the potential to mate. Aside from passerines, your others are not species which depend on vocalisations to attract a mate afaik, drakes will gang rape females to the point that they can drown.

I was however pointing out that hybridization occurs in other taxa that have very different vocals - say Blyth's and Eurasian Reed Warbler, so why? How important is vocalisation in pairing of Reed Warblers? Perhaps in Cutia's it is a definitive and Himalayan Cutia is never attracted to Vietanamese Cutia vocalizations. But, I would add you would need to do a hell of a lot of experimentation with a lot of different birds, to get even a 95% confidence limit of this fact?

The Cuttias can't hybridise because of non overlapping range, but obviously in Reed Warblers and Collared Flycatchers, sometimes the lack of attraction breaks down. So what proportion of Collared Flycatchers are attracted to Pied Flycatchers and why? - or to turn it on it's head, what keeps the species generally apart and stops them from normally hybridizing, a lack of attraction to each others vocals, looks or both? This is kind of what Tobias is all about, Collared and Pied Flycatchers are generally kept apart by X, Y and Z, so I can apply the same rules to say Atlas Flycatcher, which does not have an overlapping breeding range with Collared or Pied.

If vocals were the golden bullet, leading to thing always acting as separately species, we can't explain most hybrid events, and we would probably have to increase the number of species based on our existing knowledge of vocal differences between subspecies.

One thing to consider is that passerine vocalisations (especially song) are largely learnt by listening to nearby adults. If a young Vietnamese Cutia somehow found itself in the range of Himalayan Cutia, what song would it sing? And would it breed with Himalayan Cutia? OK, that is an unlikely example given the range and behaviour of these species, but it could be relevant for other species.

As an example, research into the Greenish Warbler complex has found that viridanus and plumbeitarsus mostly do not interbreed where their ranges meet in Russia because of different songs, and this is used to justify a split between Greenish and Two-barred. But the song type changes gradually across intervening populations around the edges of the deserts/mountains of central Asia. The song of obscuratus Greenish is more similar to plumbeitarsus Two-barred than it is to viridanus Greenish. Would obscuratus recognise the song of viridanus if they met (and vice versa)? The latest research shows evidence of gene flow between obscuratus and plumbeitarsus, and even hybrids between viridanus and plumbeitarsus, suggesting that separation by vocal differences in Russia may not be foolproof anyway.

 

[Farnboro John]

As a university drop-out I am content to recognise many of the arguments on here go over my head. However, as a birder and therefore user of taxonomy I also recognise the following:

1. Stability of names is a paramount requirement for understanding between people and historical traceability.

2. Biology is untidy and one size will NEVER fit all in any respect.

3. All this pratting about around the edges doesn't help anybody and the birds don't care!

You could freeze the whole thing for a hundred years and it wouldn't matter but would be a lot easier for everyone.

John

 

[raymie]

As a university drop-out I am content to recognise many of the arguments on here go over my head. However, as a birder and therefore user of taxonomy I also recognise the following:

1. Stability of names is a paramount requirement for understanding between people and historical traceability.

2. Biology is untidy and one size will NEVER fit all in any respect.

3. All this pratting about around the edges doesn't help anybody and the birds don't care!

You could freeze the whole thing for a hundred years and it wouldn't matter but would be a lot easier for everyone.

John

I agree with all these points and frequently point them out to people, but I don't think that means we should freeze taxonomy. We are constantly learning new things about how different groups of birds are related and IMO there's also no reason we shouldn't update our taxonomy accordingly.

 

[Farnboro John]

I agree with all these points and frequently point them out to people, but I don't think that means we should freeze taxonomy. We are constantly learning new things about how different groups of birds are related and IMO there's also no reason we shouldn't update our taxonomy accordingly.

For me that's a good reason to call a halt to the constant tinkering. As has been pointed out several times recently in the thread, science is supposed to be about facts and taxonomy currently isn't: in fact this is another manifestation of my late father's contention that whereas chemistry and to a large extent physics have passed through the observation and experimentation stages to manipulation, biology is still very much stuck in observation (i.e. trying to find out what the heck it is dealing with).

It would be good if the scientific (hah!) community engaged in this work tried a bit of humility and decided to call a halt to tinkering until it has some sort of complete picture to present to an agog world. A hundred years would seem a sensible pause from a usability point of view, enabling publications and users to move forward without having to check for minor tweaks all the time.

John

 

[Jon.Bryant]

As a university drop-out I am content to recognise many of the arguments on here go over my head. However, as a birder and therefore user of taxonomy I also recognise the following:

1. Stability of names is a paramount requirement for understanding between people and historical traceability.

2. Biology is untidy and one size will NEVER fit all in any respect.

3. All this pratting about around the edges doesn't help anybody and the birds don't care!

You could freeze the whole thing for a hundred years and it wouldn't matter but would be a lot easier for everyone.

John

I have also argued the pros of a freeze in a previous thread - field ornithology has stability, but the taxonomists can play to their hearts content in the background, only confusing us periodically. I think this would work with some things, such a freeze on Genus and Latin Name changes, but the problem with lumps and (particularly) splits is the link to conservation.

Some parties do try and conserve subspecies, but most conservation is targeted at species level. An argument for the Tobias system is speed, allowing decisions to be made rapidly and to target conservation quickly - an important issue when their is so much pressure on the environment and a decline of many taxa. How many species will have gone extinct by the time we manage to undertake full genome testing on all the different types of aves, including all currently known species and subspecies?

On this basis, I think scientists need to continue trying to identify new species, not to mess with our lists, but for conservation, particularly if the new species are likely to need immediate action to ensure their survival. We could argue that work on 'disproving' a species and the resultant lump is a bit unnecessary, and potentially detrimental if it results in a potential curtailment of conservation work. We have previous discussed on the forum whether species definitions are 'political' - split it to protect it, but I actually think this is fine, and it is best to be safe than sorry... and what would be the worst consequences - a bit more inconvenience for us, but on the upside probably bigger lists.

I think it would be more messy still if conservationists (who may also need to work on local community engagement), were using a different 'taxonomy' to a frozen one used by birders.

 

[Farnboro John]

I have also argued the pros of a freeze in a previous thread - field ornithology has stability, but the taxonomists can play to their hearts content in the background, only confusing us periodically. I think this would work with some things, such a freeze on Genus and Latin Name changes, but the problem with lumps and (particularly) splits is the link to conservation.

Some parties do try and conserve subspecies, but most conservation is targeted at species level. An argument for the Tobias system is speed, allowing decisions to be made rapidly and to target conservation quickly - an important issue when their is so much pressure on the environment and a decline of many taxa. How many species will have gone extinct by the time we manage to undertake full genome testing on all the different types of aves, including all currently known species and subspecies?

On this basis, I think scientists need to continue trying to identify new species, not to mess with our lists, but for conservation, particularly if the new species are likely to need immediate action to ensure their survival. We could argue that work on 'disproving' a species and the resultant lump is a bit unnecessary, and potentially detrimental if it results in a potential curtailment of conservation work. We have previous discussed on the forum whether species definitions are 'political' - split it to protect it, but I actually think this is fine, and it is best to be safe than sorry... and what would be the worst consequences - a bit more inconvenience for us, but on the upside probably bigger lists.

I think it would be more messy still if conservationists (who may also need to work on local community engagement), were using a different 'taxonomy' to a frozen one used by birders.

Personally I think the opposite. If there wasn't so much fuss about alleged species that are just populations on different islands then conservation could concentrate on populations that are realistically sized and savable, and for that matter birders could cut down on the number of flights they take to island destinations to see the same bird with a different island name in front of it.

John

 

[jts1882]

I think the problem with changing taxonomy is letting it change the list of birds you have seen. If you observe a new species, then you have the pleasure of seeing it and adding it to your list. If the species is subsequently lumped, it doesn't change the experience. Similarly, a species split doesn't add to the collection of experiences. The problem is really counting armchair ticks and lumps.

 

[Jon.Bryant]

Personally I think the opposite. If there wasn't so much fuss about alleged species that are just populations on different islands then conservation could concentrate on populations that are realistically sized and savable, and for that matter birders could cut down on the number of flights they take to island destinations to see the same bird with a different island name in front of it.

John

I think that a large majority of extinctions to date are island species, and I personally lament what has happened regardless of how 'saveable' they were - and we can see that even for apparent hopeless cases, like Black Robin, conservation can still defy the odds and turn around something that seems impossible.

I also suspect that you would not want to see 'existing' island species go extinct - say Tristan Albatross, where the rat problem and eradication has been ongoing and challenging. But we could argue that Tristan Albatross is one of those that falls in the 'same bird on a different island' category, particularly as it was only fairly recently separated from the Wandering Albatross complex. It seems a bit stark to say, protect 'cryptic' species but only up to an arbitrary cut-off date for recognition of the taxa as a species.

As for flights, it is a good thing to lead by example, but unfortunately flights continue while viable. Until there is a wider change in attitude to flights for vacations and business, I think the absence of birders on flights will not disrupt the market - flights will still happen, but perhaps with a few less passenger and perhaps a bit more commercial cargo. Until everyone turns their back on flying, unfortunately having a few less flights taken by birdwatchers, does not really achieve a net environmental benefit.... and there are plenty of examples where conservation is helped by birding tourism, take for instance increased illegal trapping of songbirds in Indonesia during the Covid lock-down, where OBC has reported that the absence of birdwatcher tourists led to more trapping, as trappers could go about their business without the risk of being observed. In other cases the benefit may be purely financial and allow locals to monetarist their natural assets, particularly important for species that may otherwise only be valued as a food source. So not travelling may in some cases ultimately lead to an environmental detriment.

 

[raymie]

For me that's a good reason to call a halt to the constant tinkering. As has been pointed out several times recently in the thread, science is supposed to be about facts and taxonomy currently isn't: in fact this is another manifestation of my late father's contention that whereas chemistry and to a large extent physics have passed through the observation and experimentation stages to manipulation, biology is still very much stuck in observation (i.e. trying to find out what the heck it is dealing with).

It would be good if the scientific (hah!) community engaged in this work tried a bit of humility and decided to call a halt to tinkering until it has some sort of complete picture to present to an agog world. A hundred years would seem a sensible pause from a usability point of view, enabling publications and users to move forward without having to check for minor tweaks all the time.

John

Taxonomy isn't fact, but it is informed by facts, why shouldn't we change it based on new facts we learn? Although I would generally be in favor of fewer larger updates than what we currently have.

 

[Mysticete]

Taxonomy isn't fact, but it is informed by facts, why shouldn't we change it based on new facts we learn? Although I would generally be in favor of fewer larger updates than what we currently have.

We are basically reaching a point where there should be fewer and fewer changes, and the changes occurring at lower levels. We have multiple comprehensive phylogenies the vast majority of bird species at this point have appeared in at least one study. Higher level taxonomy mostly has a consensus. We sort of know how everything fits together above the genus level, and there should be progressively fewer changes at the genus level. It's really only species and subspecies where I see further major changes