Latest IOC Diary Updates (8 Viewers)

[Swindon Addick]

Sep 22 Post proposed split of Tenerife Robin <...> from European Robin.

A candidate for the least satisfying armchair tick ever...

 

[Owene]

So you now want me to check where I have seen robins? This is unfairly advantageous towards people who actually make notes Also what is the difference, as far as I recall the robins look really the same everywhere?

Much redder much smaller bib. My guide in Tenerife was pushing how different all the subspecies there were but Robin was one of the ones that genuinely did seem different to me


That said it didn’t look as different as the (blue not Tenerife Blue) chaffinches which would be a really awkward split

 

[opisska]

It actually seem like I haven't seen any Robins on either island. They also seemingly occur on La Palma and La Gomera, what species is that now?

 

[awiner]

It actually seem like I haven't seen any Robins on either island. They also seemingly occur on La Palma and La Gomera, what species is that now?

Looks like it's nominate rubecula.

 

[opisska]

But that surely must be just taxonomic laziness, not a reflection of the reality, no?

 

[awiner]

But that surely must be just taxonomic laziness, not a reflection of the reality, no?

Nope, https://onlinelibrary.wiley.com/doi/10.1111/zsc.12561 included sampling birds on La Palma and La Gomera. They're just rubecula.

 

[opisska]

I don't know. This just seems to me like the molecular interpretation of species must be lacking somehow. How does that actually happen in evolution? The birds on La Palma and La Gomera surely cannot have more gene flow with the rest of the population of the species than the birds on Tenerife and Gran Canaria have. If the birds on those two islands are sufficiently distinct from the Tenerife/Gran Canaria birds that the those populations are considered different species, how can they simultaneously be NOT distinct from all the birds that live thousands of kilometers away?

 

[njlarsen]

I don't know. This just seems to me like the molecular interpretation of species must be lacking somehow. How does that actually happen in evolution? The birds on La Palma and La Gomera surely cannot have more gene flow with the rest of the population of the species than the birds on Tenerife and Gran Canaria have. If the birds on those two islands are sufficiently distinct from the Tenerife/Gran Canaria birds that the those populations are considered different species, how can they simultaneously be NOT distinct from all the birds that live thousands of kilometers away?

Without reading the paper for their proposals of how: early invasion of what is now the new proposed species, followed by local extinction on those two islands, followed by a second invasion to these islands of the European form?

 

[Jacana]

Would not be unusual in the Canary Islands. See the messy pathway of colonisation and recolonisation of the islands seen in the African Blue Tit and Common Chaffinch systems there.

 

[pbjosh]

Indeed there seem to be pretty good understanding / data now, bit by bit, for multiple colonizations and messy histories for several species in the Canarias. I am almost surprised that there aren’t more larks and sparrows and other birds to have colonized. And makes you wonder about the genetics of „mainland“ species on Cape Verde too…

 

[Mysticete]

Indeed there seem to be pretty good understanding / data now, bit by bit, for multiple colonizations and messy histories for several species in the Canarias. I am almost surprised that there aren’t more larks and sparrows and other birds to have colonized. And makes you wonder about the genetics of „mainland“ species on Cape Verde too…

Yeah this sort of pattern of complex colonizations, extinctions and reinvasions seems to not be a uncommon thing in island birds. I recall similar patterns being noted in some songbirds in the South Pacific and SE Asia.

 

[tony.saw]

What is the authorship of T. albocoeruleus ?

Have a look at the recent paper by Per Alstrom et al Cryptic species in a colorful genus: Integrative taxonomy of the bush robins (Aves, Muscicapidae, Tarsiger) suggests two overlooked species It's open source.
Tony

 

[l_raty]

Have a look at the recent paper by Per Alstrom et al Cryptic species in a colorful genus: Integrative taxonomy of the bush robins (Aves, Muscicapidae, Tarsiger) suggests two overlooked species It's open source.
Tony

Oh yes, true - it's in the paper, actually. I had originally failed to find it because I looked for an author name adjacent to the taxon name... But it appears as a statement :

"the taxon ‘albocoeruleus’ breeding in mountain ranges in northeast Qinghai, north Gansu, Shanxi and Beijing (Townshend, 2021), described by Meise in 1937 as a subspecies of T. cyanurus".

 

[Jim LeNomenclatoriste]

Have a look at the recent paper by Per Alstrom et al Cryptic species in a colorful genus: Integrative taxonomy of the bush robins (Aves, Muscicapidae, Tarsiger) suggests two overlooked species It's open source.
Tony

As said Teal'c "indeed"

 

[opisska]

Well here I have shown my ignorance It did not occur to me that the absurd genetic patterns can be due to long histories of colonisations ... I have discussed it also with my friends who are evolutionary biologists (but working on unicellular organisms, not birds) and they find these explanations feasible, even though they do show general reservations regarding straight up molecular definitions of species and suggest we bring the birds together and ask them to mate

 

[Markus Lagerqvist]

Well here I have shown my ignorance It did not occur to me that the absurd genetic patterns can be due to long histories of colonisations ... I have discussed it also with my friends who are evolutionary biologists (but working on unicellular organisms, not birds) and they find these explanations feasible, even though they do show general reservations regarding straight up molecular definitions of species and suggest we bring the birds together and ask them to mate

Regarding the robin split, the study do combine the molecular results with morphology, song/calls and the subspecies on Gran Canaria and Tenerife differ both in plumage and, perhaps more importantly in both song and alarm and begging calls. Stock och Bergmann (1988) previosuly showed in play-back tests that superbus (Tenerife) doen't respond as strong to rubecula song as to suberbus song.

 

[Xenospiza]

I am still quite surprised that differences in song and call of oscine songbirds are now used to separate closely related taxa as species.
I thought the whole point of oscine songbirds was that they learn their songs and as such it is very weak evidence?
See also Chaffinch, Bullfinch, Crossbill, Firecrest...

(The avifauna of the Canary islands is remarkably depauperate. I assume dry periods, volcanic eruptions and possibly regular arrival of continental migrants must have wiped out more interesting species, with a few endemics finished off by the Guanches & Spaniards).

 

[Jacana]

Songs are learnt, but calls are innate. So vocalisations can be a useful component for species delimitation.

 

[l_raty]

This is by no mean absolute.
Crossbills, in any case, learn their calls. (Young birds fostered in captivity by adults with a call type different than that of their biological parents have ended up calling like their foster parents. There are also known cases of adult birds that switched from one call type to another to match the call of the group they associated with.)

 

[Jacana]

There is evidence that Crossbill calls are not typical calls though and that they may be derived from "song" vocalisations, rather than "call" vocalisations.