Nesoenas rodericana (Rodrigues Turtle Dove)

[another specialist]

Streptopelia rodericana
(Milne-Edwards) 1873
Recent, Rodrigues, e Mascarene Islands, wc Indian Ocean
Primary materials: Type: Sternum, humerus, femur, tibiotarsus, tarsometatarsus

Kàlmàn Lambrecht,
Handbuch der Palaeornithologie
1024 p. (1933)
Gebrüder Borntraeger, Berlin

See also:
Pierce Brodkorb,
Catalogue of fossil birds. Part 4 (Columbiformes through Piciformes)
Bulletin of the Florida State Museum, Biological Sciences 15 (1971): 163-266

www.ornitaxa.com/SM/Fossil/FossilColumb.htm

[dysmorodrepanis]

The sternum does not belong to this species, and it is not synonymous with "Alectroenas" rodericana (see there). The remainder of the bones seem to do, but at least the tarsometatarsus is obviously inseparable from Columba picturata (new genus for Streptopelia picturata):

Cécile Mourer-Chauviré, Roger Bour, Sonia Ribes & François Moutou,
The avifauna of Réunion Island (Mascarene Islands) at the time of the arrival of the first Europeans
in Avian Paleontology at the Close of the 20th Century: Proceedings of the 4th International Meeting of the Society of Avian Paleontology and Evolution, Washington, D.C., 4-7 June 1996. Storrs L. Olson editor 89 (1999): p.27

As C. picturata has evolved into a number of island subspecies and occurs in the entire Madagascar region up to the Seychelles, this probably was a distinct subspecies.

Populations also occurred on Réunion and Mauritius, became extinct, and were later replaced by the nominate subspecies from Madagascar. It was believed that the bones found belonged to introduced birds, but at least the Réunion subfossils predate human arrival (same reference, p-28).

Since the prehistoric occurrence of C. picturata has been confirmed on Réunion, it should be checked if the material from Mauritius is prehistoric also. At any rate, it seems more than likely, given the distribution and subspeciation pattern of the species, that the Réunion form was a distinct subspecies. As there is little variation in the Comoros, any prehistoric population from Mauritius would likely belong to the same subspecies than the one from Réunion.

The Rodriguez taxon is another matter; Rodriguez is farther away from the other Mascarenes than the average distance between picturata subspecies. While it is not really likely that the Rodriguez form was a distinct species, it might just be so (the nearly extinct Seychelles subspecies rostrata, the most distant existing subspecies, could morphologically well be considered a good species, but as its history of decline illustrates, it hybridizes all too well with the introduced birds...). At any rate, I would prefer to consider it a subspecies, in which case the correct name would be Columba picturata rodericana.

(Note: we do not have a thread on C. p. rostrata. It should be in the Endangered Birds section, as some individuals still survive.)

[Carlos]

I'm a little bit at a loss.

I gather that there are two species involved in this thread. First the sternum upon which Columba/Alectroenas rodericana was described by Milne-Edwards and that seem to correspond with the slate pigeons described by Leguat in the XVIIth century, and, in the other hand the smaller form of a (probably undescribed) subspecies of Columba/Streptopelia picturata.

Am I right?

If so, I find strange that Leguat didn't mention this second dove species at Rodrigues Is during its stay there in 1691. Or perhaps both species were slate coloured and Leguat didn't tell them apart?

[dysmorodrepanis]

To clear this up (my bad):

The sternum does in fact belong to "A." rodericana. I was mistakenly assuming that the grey pigeons were another species of which no bones had been found yet.

As a matter of fact, the site of Leguat's settlement should be traceable. I wonder why nobody has excavated it. Perhaps it has been built over and is not accessible anymore or has been destroyed by earthworks. This would be a pity, since the midden heaps should resolve which pigeons the Huguenots ate.

[Carlos]

So, if I understand well, Alectroenas rodericana is a good taxon, described upon one sternum by Milne-Edwards in 1874, and still, there are other remains referable to another undescribed taxon close to Streptopelia picturata.

I gather that Leguat's grey pigeons should refer to A. rodericana and that the Streptopelia doves went unnoticed to the huguenots in the XVIIth century (if they were still a living species by then).

A thread has been created for the other species here

Alectroenas rodericana
extinctanimals.proboards22.com/index.cgi?action=display&board=columbiformes&thread=1115714977&page=1

[dysmorodrepanis]

carlos said:

So, if I understand well, Alectroenas rodericana is a good taxon, described upon one sternum by Milne-Edwards in 1874, and still, there are other remains referable to another undescribed taxon close to Streptopelia picturata.

I gather that Leguat's grey pigeons should refer to A. rodericana and that the Streptopelia doves went unnoticed to the huguenots in the XVIIth century (if they were still a living species by then).

Am I close to the end of this maze?

Well, the grey pigeons are probably the species called Columba or Alectroenas rodericana (described from the sternum), only that they did not belong to either genus, but were an indigenious kind of ground dove. The fossils are neither numerous nor well-researched enough to resolve what genus exactly it was (or rather, to set up a new one), but when they were described as "Columba", that genus was rather a hodge-podge. I bet Milne-Edwards would not have agreed with the birds being called Alectroneas, That Leguat says "we called them our chickens" is very suspicious, because Alectroenas is rather arboreal in habit, and for what it's worth, the Mauritius species was the largest of the genus, being nearly as large as a domestic pigeon.

The bird called Columba/Streptopelia rodericana is only known from leg bones. I guesstimated on Wikipedia that it was already extinct before Leguat arrived on the island, but why rats should have killed off an arboreal bird and spared the terrestrial one is not clear. It is certain that the island was overrun with rats when Leguat arrived, and it is probable that these were Black Rats (Rattus rattus) which like to climb a lot, nest in trees etc (they are also called Roof Rats) and not Brown Rats (Rattus norvegicus or Ship Rats) which seem to have arrived in the 18th century only.

So what is known is far from sufficient, but at least there are no glaring contradictions. The theory with a pre-Leguat extinction of Streptopelia=Columba rodericana is shaky at best, but at least it does not fly right apart.


Compare with the situation on Réunion:
There seems to have been an Alectroenas on Réunion ("ramiers of the species with blue wings") and the Streptopelia (nowadays Columba) picturata population there was probably the birds called tourterelles (turtle-doves). Then there was the "russet pigeons" which were most probably Nesoenas (also Columba nowadays) duboisi. That leaves the Réunion slate-colored pigeon which was described in addition to ramiers, tourterelles and the russet birds.

What this bird might have been nobody has ever been able to explain. There is only scant written material, just as with the "other" parrot of Mauritius, the grey parrot of Réunion, the green parrot of Rodrigues and the green-and-red "Necropsittacus".

[Carlos]

Thanks for your reply, as authoritative and in-depth as always. Yes, the situation is far from clear and my confusion arises from the species name rodericana, and the confusing genus Columba applied to both taxa in different moments.

And I'm not the only one, looking at some of the posts in both threads, mixing information on both species up.

[dysmorodrepanis]

Did you think it was all over?

It gets worse:

The Pink Pigeon and the Madagascar Turtle Dove form an early offshoot of the Columba-Streptopelia divergence (as do the Chinese Turtle Dove and the Laughing Dove, but that's another matter).

Johnson et al conclude here www.inhs.uiuc.edu/~kjohnson/kpj_pdfs/Auk.2001.pdf - somewhat cheekily, I'd have to add - that these two would have to go into Streptopelia. And since this here rodericana (the one known from bones but not from descriptions) is close to the Madagascar species, off it goes into Streptopelia.

So at least there is no Columba involved anymore.

But wait, there's more:

I said "cheekily" because the molecular divergence of the two two-bird offshoots mentioned above places them right between Columba and Streptopelia. Indeed, the strict consensus tree puts them firmly into Columba, while the maximum likelihood tree puts them into Streptopelia. Since evolution is not statistics and programming sleigh-of-hand but something that can be traced back in genes just as badly as it can be in morphology, the smart scientist's choice would have been to put the Madagascar Turtle Dove and the Pink Pigeon into Nesoenas and forget about the issue. I wonder why they didn't; checking out the Peters checklist, it makes me wonder if we have molecular biologists at work which are too inexperienced or lazy to dig through the synonymy of the other two offshoots (I do not find myself able to pick a correct genus name for the Afro-Asian "dirty pair" from Peters, which is a very bad sign).

So, at any rate, brace yourself for this species being dumped into a newly-revived Nesoenas together with "Columba" duboisi and "Columba" picturata and "Columba" mayeri there to party in the limelight of that last species' celebrity status or whatever.

Sigh.

At any rate, here's the taxonomy of the 4 (6?) Mascarene taxa as it now stands and as I read it:

Réunion:
- Streptopelia duboisi: Réunion Pink Pigeon
IMHO Nesoenas duboisi

- Streptopelia picturata ssp.: Réunion "tourterelle" (Dubois)
IMHO Nesoenas picturata ?ssp. nov.

- ?Alectroenas sp. indet.: Réunion "ramier" (Bontekoe/Dubois)
IMHO Alectroenas ?sp. nov.

- Réunion "slate-grey pigeon" (Dubois)
IMHO... I don't have the slightest idea and the less I have to think about it the better.


Rodrigues:
- Streptopelia rodericana: Rodrigues Pigeon/Turtle Dove
IMHO Nesoenas rodericana

- Alectroenas rodericana
IMHO Columbidae gen. nov. (cf. Gallicolumba) rodericana

[dysmorodrepanis]

Ha! I got it! How could I have overlooked this?

As to why nobody writes about this bird, but both Leguat and Tafforet (the author of the "Rélation...") talk at length about the "Alectroenas": the latter bird, as evidenced by these texts, nested on offshore islets! So that's why it did not became extinct when the rats overran Rodrigues!

[Carlos]

Thanks a lot, Dysmorodrepanis for such amount of new (at least to me)information.

Yes. I also thought that both, Leguat and Tafforet took the last chance to see the very last Rodrigues pigeon/dove species alive. Just before the rats got to those offshore islets.

Any case, I'm about committing suicide before undergoing any more epic attempts to untangle such complicated matter of: How many bl***y pigeons did once live in the Mascarenes? ;D

[dysmorodrepanis]

carlos said:

Any case, I'm about committing suicide before undergoing any more epic attempts to untangle such complicated matter of: How many bl***y pigeons did once live in the Mascarenes? ;D

6 to 8.

The 4-6 mentioned above, the Pink Pigeon, and the Pigeon Hollandais, both of Mauritius. There is one report of "bisets" on Maurititius, but I think that can be dismissed as the textn is about pigeons of Mauritius as well as Madagascar.

Funny that the question of Mauritius pigeons should be so straightforward while that of those on the other two islands is so very confusing.

I am currently putting every Wikipedia article on extinct birds that is not already in the English one in the latter. Next will be (after some rest & recuperation in the form of a decent barbecue - no pigeons involved, heh) Necropsittacus. Oh my. But after doing the Rodrigues Grey Pigeon and the Mascarene Parrot, I think nothing can shock me anymore. Oh, the horror that are the stories of rusty-red parrots on Mauritius... in the utter absence of bones of Mascarnius mascarinus there... I can only guess that Cheke got it dead wrong when he attributed tese birds to Lophopsittacus...

[Carlos]

dysmorodrepanis said:

Oh my. But after doing the Rodrigues Grey Pigeon and the Mascarene Parrot, I think nothing can shock me anymore. Oh, the horror that are the stories of rusty-red parrots on Mauritius... in the utter absence of bones of Mascarnius mascarinus there... I can only guess that Cheke got it dead wrong when he attributed tese birds to Lophopsittacus...

;D ;D ;D

Yes, quite a challenge. But I'm sure you'll sort it out most competently
BTW, that barbecue sound a most decent way to prepare yourself for that task.

[dysmorodrepanis]

It actually turned out to be a big huge pot of chili. But it was well worth it. Work is progressing steadily.

[another specialist]

Streptopelia (picturata) rodericana is not the same as Alectroenas rodericana

This two birds are completely different unrelated species

Alectroenas rodericana

extinctanimals.proboards22.com/index.cgi?action=display&board=columbiformes&thread=1115714977&page=1

[Melanie]

Rodrigues Pigeon Alectroenas rodericana is known from subfossil bones from Rodrigues, Mauritius, and descriptions from Leguat in 1708 and from Tafforet in 1726 . It presumably became extinct in the first half of the 18th century, possibly due to the depredations of introduced rats.

[another specialist]

the above can be found here

www.encyclopedia.mu/Nature/Fauna/Birds/Extinct/RodriguesPigeon.htm

[another specialist]

and here also

www.iucnredlist.org/search/details.php?species=23329

[dysmorodrepanis]

This was certainly not an Alectroenas. The only known specimen seems to be a sternum, which is so unusual that it cannot be assigned to any genus compared: Alctroenas, Streptopelia, Treron, Ducula, Gallicolumba, Columba (including Nesoenas).

Possibly, an unidentified femur belongs to the species also (but this is large and slender and would make it look even more unusual). The tarsometatarsi can be assigned to Columba (= Streptopelia) (picturata) rodericana:

Cécile Mourer-Chauviré, Roger Bour, Sonia Ribes & François Moutou,
The avifauna of Réunion Island (Mascarene Islands) at the time of the arrival of the first Europeans
in Avian Paleontology at the Close of the 20th Century: Proceedings of the 4th International Meeting of the Society of Avian Paleontology and Evolution, Washington, D.C., 4-7 June 1996. Storrs L. Olson editor 89 (1999): p.27; see also extinctanimals.proboards22.com/index.cgi?board=columbiformes&action=display&thread=1117992139

The specimen is closest to Gallicolumba. It seems to look hardly like a pigeon's at all. This was a small species, about 20 cm in length, but not flightless or terrestrial. Since Rodriguez is quite small and quite old and had 3 species of flightless or at least terrestrial birds, one of which was derived from pigeon stock, it is conceivable that this species was derived from an early South Asian colonization along with the Solitaire's ancestors, competitive exclusion preventing it from becoming flightless. A comparison with Macropygia or generally members of the Australasian "proto-Geophaps" clade might be interesting. All that can be said is that the one characteristic bone is probably not even remotely like anything from the African region (though I don't know if it has been compared to Turtur).

Indeed, Alectroenas is derived from just that early colonization: it is an offshoot from the proto-Ptilinopus stock. So the genus to which the Rodrigues bird is assigned may indeed be its closest relative - but it does not belong there.

[another specialist]

birdlife class it as valid and still list it as such

www.birdlife.org/datazone/search/species_search.html?action=SpcHTMDetails.asp&sid=30087&m=0

[another specialist]

Image reference: 35853

Title: Alectroenas rodericana, Rodrigues pigeon

Description:
This species was native to Rodrigues Island, Mascarene Islands, Indian Ocean. They are illustrated here sitting on the last wild specimen of tree Zanthoxylum paniculatum. Illustration by Julian Hume.

piclib.nhm.ac.uk/piclib/www/image.php?search=julian%20hume&getprev=81612