Undescribed bird in Madagascar? (1 Viewer)

[lewis20126]

I think it is worth looking at the text in the BLI checklist v2, closest relative the Yellow-brow IIRC?

cheers, alan

 

[DMW]

Have just noticed that in post 31, I passed on Tring data that one specimen was taken in 1924 and one in 1925. Would be quite a coincidence if both were at similar stages of moult and showed short, narrow tails when in fact DT doesn’t possess that feature. Almost impossible I would suggest. Am strongly tempted to think that we are seeing the true structure of DT in the photos.

Fair point. I'm just struggling to think of any passerines that have such a proportionately weedy tail.

 

[abirdingguy]

Nice! Thank you for sharing.

For what it's worth, the 2015 Helm field guide also notes that the shorter tail of the Dusky Tetraka could be one of the most useful features for field identification. The accompanying illustration also shows a slightly shorter tail for the Dusky. The difference in tail length appears more apparent in the photos of the skins, than in the guidebook illustrations. Take this statement with a grain of salt as I do not have a lot of experience looking at skins.

The family of birds that we saw in November 2017 seems to fit better with the Spectacled skins. (A photo of the live bird was provided earlier in this thread from user Tapaculo.) The more yellowish, less "grimy" underparts and the relative tail length seem to me to be the most prominent evidence for Spectacled. Also my initial "jizz" in the field was that the bird that we saw more closely resembled the Spectacled as described and illustrated in the Helm guide primarily due to it's more horizontal, elongated silhouette as compared to what I expected to be a more compact and upright Dusky.

Thanks again to all who have been contributing to this thread. I'm still open to sharing my recordings of this Tetraka if there is any interest.

 

[amears]

Fair point. I'm just struggling to think of any passerines that have such a proportionately weedy tail.

Banded and Gurney’s Pittas fit this bill quite nicely. I can’t imagine that DT will prove to have their ‘extreme jizz’ but it would be wonderful if it did...!

Yellowbrow, etc, were mentioned several times earlier in the thread, by the way.

 

[amears]

[Just a correction to my post 24. Mantadia is very well known and visited by many birders. I was mixing it up with Mananara lodge, Anjozorobe...]

 

[DMW]

Banded and Gurney’s Pittas fit this bill quite nicely. I can’t imagine that DT will prove to have their ‘extreme jizz’ but it would be wonderful if it did...!

Hah, I knew somebody was going to think of something! You are right, they do appear to have quite similarly proportioned tails as these birds.

 

[lewis20126]

I do not think there are any convincing records of Dusky Yellowbrow. There are no photographs of live birds, no recordings and no known locations of extant populations. I will ask pete morris to comment.

Cheers, alan

 

[petemorris]

I do not think there are any convincing records of Dusky Yellowbrow. There are no photographs of live birds, no recordings and no known locations of extant populations. I will ask pete morris to comment.

Cheers, alan

I've still not found any from any of the frequently birded areas. To the best of my knowledge, they have never been mist-netted or photographed on the Masoala Peninsula, Perinet/Mantadia area or Ranomafana, and no specimens exist from these areas. As the sister species to Madagascar Yellowbrow, they should be one of the first species to end up in the bottom shelf of a mist net.

They have, partly because of the misleaing illustrations/literature, been frequently misidentified by local guides and visiting birders alike. I would be surprised if there is another species in the world that has been mis-identified and listed by a higher percentage of erroneous claims. By that I mean that of the x100 birders that have ticked it, it may likely have only be seen genuinely by one birder??!!

One day a good site in its actual range will come to light, and some in the field (or at least in the hand) photos will come to light. Until then, Spectacled Tetraka will count two on many unsuspecting World Birders' lists!

Cheers and good birding

Pete

 

[amears]

Great to hear Pete's take on this. Sianaka Forest would be the obvious place to start of course. I've asked the Peregrine Fund if they are interested in following this up.

'Dusky Ground-warbler' and 'Yellow-browed Ground-warbler' perhaps...?

 

[amears]

Peregrine Fund field staff might be able to visit Sianaka Forest late in 2018 to search for DT - hope they manage to do that and I'll look forward to the results...

 

[jurek]

It seems surprising that the Dusky Tetraka groups with the Madagascar Yellowbrow, although it is visually almost identical to Spectacled. Were other scenarios excluded (eg. it is a hybrid)?

One little thing: another difference seems that Spectacled Tetraka has yellow throat and middle of the belly, but Dusky has darker belly. This may help in the field.

 

[custard]

The classification of Yellowbrow as a sister taxon is based on a PhD thesis (N L Block 2012, Cryptic Diversity and Phylogeography in the Bernieridae, an Endemic Malagasy Passerine Radiation, University of Chicago) which is I believe unpublished (I have not searched for a precis on-line). I am told the list of museum specimens includes juvenile birds.

 

[custard]

Best ref. is Birds of Africa (which I'm afraid I don't have). The 2015 FG by Frank Hawkins (who I believe has actually seen one) describes and illustrates the short tail, also lists narrower yellow throat and eye ring and darker breast band (discernible in photos on this thread). Gives relatively longer and stouter legs as a feature too, presumably related to habits which are said to be largely terrestrial, not venturing above 0.5 m. C.f. its validity there are, I believe, juvenile specimens and a PhD thesis established Yellowbrow as a sister taxon (c.f. my reply to a post above for a reference of sorts, it is unpublished). Have tried repeatedly to reply specifically to the post that included the photos but my efforts keep appearing here.

 

[amears]

Very interesting info, custard. Do you know where Frank saw the species and where the juvenile specimens were taken from? (Or any other specimens for that matter that aren’t held at Tring...?). A first hand account from Frank would be really good to hear.

 

[custard]

I am not certain Frank Hawkins has seen it but he is listed as the sole author of a CI survey report which appears to be the source of one one of the few recent records regarded as reliable. It is from Zahamena NP, a locality not really visited by non-resident birders. I spent two months surveying lemurs there in 1999 with Sam Woods, hence my interest in the species. We saw a couple of birds we wondered about briefly but concluded they were Spectacled. It appears that we were correct as I don't think Dusky has been recorded in the sector of the park in which we were working, which I think was probably a little high for it (HBW gives elevation for Dusky as up to 950m). There is a voice recording listed on Hawkins and Ranft, Bird Sounds of Madagascar. There is some specimen data in Birds of Africa, which as I say is the best reference. I don't have it but managed to find some pages on line and it appears there are 3 specimens in AMNH, New York and the 2 juveniles, which are actually referred to as 'presumed this species', are in MNH, Paris. Don't now where they were taken.