Mystery Bird: Ashy Drongo, Dicrurus leucophaeus

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[Mystery bird] Ashy Drongo, Dicrurus leucophaeus, photographed at the small village of Muang Khong, near Chiang Dao Mountain, northern Thailand. [I will identify this bird for you in 48 hours]

Image: Dirk S. Schmeller, November 2009 [larger view].

Nikon d90 with a Nikon lens 80-400, 1/400 s f/16 at 400mm iso400.

Please name at least one field mark that supports your identification.

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More used to identifying inverts than birds, but I am pretty sure its an Ashy Drongo (Dicrurus leucophaeus), saw one during my time in Tailand last year, im more than willing to accept a differing I.D. though.

By Aberdeen23 (not verified) on 18 Dec 2009 #permalink

The long forked tail leads to it being a Drongo. There appears to be some greyish makings on the undersides so I agree with Aberdeen, an Ashy Drongo. Also I saw them in India last year.

Iâm going to have to take a couple of stabs at this, but my first impression also is of a Drongo, although I've only ever seen the Madagascar Crested Drongo, Dicrurus forficatus (I think "drongo" is actually a Malagasy word), and the one from Sulawesi, Dicrurus montanus.

From the 26 species I can find, I think 21 can be excluded for range, but because drongos are highly migratory, I have included those recorded as common in Myanmar (Burma) and Laos, both countries bordering northern Thailand where this photo was taken, as well as Thailand itself.

Of the 5 remaining, both the Lesser and Greater Racket-tailed Drongos (D. remifer/D. paradiseus) can be eliminated because of the shape of the tail (although the juveniles lack the âracketsâ, their tails are still not forked) leaving us with: the Ashy, Dicrurus leucophaeus (14 subspecies across South and Southeast Asia); the Crow-billed, Dicrurus annectans (monotypic in Bangladesh, Bhutan, Brunei, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, the Philippines, Singapore, Thailand, and Vietnam); and the Hair-crested , Dicrurus hottentottus (14 subspecies throughout Bangladesh, India and Bhutan through Indochina to China, Thailand, Cambodia, Laos, Indonesia, Brunei, and the Philippines).

Until I do a little more digging and work out whether what I see is coloration or sunshine, Iâm working on one of those three.

By David Hilmy (not verified) on 18 Dec 2009 #permalink

Hi David
To help you along, there is also Black (Common) D. macrocercus and Bronzed D. aeneus present here. The tail of the bird in the photo doesn't appear to be deeply forked enough for the first and Bronzed doesn't show brown in the wings though, Crow-billed does have a heavy crow-like bill which this bird does not and Spangled (aka Hair-crested) doesn't have a forked tail. On shape alone it's either Black or Ashy and even if the greyish colour is an effect of sunlight on Black it should appear shiny which this doesn't, so I'll stick with Ashy Drongo.

Thanks Adrian!

I see that three of the 7 subspecies of the Black do venture into Thailand (albirictus, cathoecus, and thai) and although major range distributions do not include Thailand, that there are records (and photos) of the Bronzed (ssp. aeneus) from Doi Ang Khang in the north-west (unsurprising because of constant references to the strong "migratory nature" of this genus.)

When I enlarged the photo this morning I decided that the sun must be shining from the upper left and therefore the light look to the underparts of this bird's left wing must be color and not illumination- the sun's angle also highlights the glossy blue color to the nape, consistent with Ashy, Hair-crested, and Crow-billed- I'm not sure that the "crow-like" bill would be excluded from our photo because of the photographic angle, but would have expected to make out the white rictal spot if this were indeed a Black.

(Differentiating between the fork in the tail of all 5 of these species is taking me back down that dark Quasimodoesque path from which I thought I had escaped when looking at the wrens! Are there differences between the species we are considering?)

I must of course bow to your personal observations and so accepting that this is very probably an Ashy, time to explore which form: the various subspecies of Ashy have varying amounts of grey (and several have distinctive white markings on the head), I get the impression of a bird with mid-grey below, and the distinctive blue-black above (nape), so...

we can exclude a number of the 14 subspecies because of range and of the 5 recorded for Thailand in particular, because of variations in coloring, we can exclude both leucogensis and salangensis because they are the white-faced forms, and also mouhoti which is a uniformly light grey (upper and lower), and also bondi which is reputedly one of the very light greys... looking at a range map of the subspecies of Ashy Drongo, I think we'll find that Chiang Dao Mountain in the North falls between nigrescens, mouhoti, and bondi leaving us really with the first as a possibility plus hopwoodi, too far north according to the map but historically recorded in Phuket (Smithsonian Museum of Natural History Checklist of the Birds of Thailand, 1963) with a number of sightings recorded for the northern mountains via GlobalTwitcher.

Therefore Ashy Drongo, Dicrurus leucophaeus nigrescens or hopwoodi.

By David Hilmy (not verified) on 19 Dec 2009 #permalink

Hi David,
My Birds of Thailand by Craig Robson gives the following; "Mouhoti breeds NW, northern NE and visitor elsewhere, dark steely-grey somewhat paler below darker lores and shallower tail-fork than Black. Nigrescens resident in South, salangensis visitor central, SE and S. Bondi resident W, southern NE and SE, hopwoodi winter records from NW and NE." As Chiango Do is in the NW I think this is most probably D. leucophaeus mouhoti, although a better photo might prove me wrong!

Thanks again Adrian, you are probably right.

I found this reference to D.l.nigrescens:

"Extreme southern Myanmar, southern Thailand and Malaysia. Plumage is black with slight gloss above and darker below. Resembles Black Drongo in shape and proportions but is never as black."

And this record describing the discovery of D.l.bondi which I may have misread as describing mouhoti as pale grey when in fact the author appears to have been comparing how much paler bondi was to mouhoti:

"the resident grey drongo of the district in which bondi was collected, it differs in its very much paler coloration both above and below, absence of black on the forehead, plae grety instead of black outer webson the outer tail feathers and dusky brownish instead of black primaries"

By David Hilmy (not verified) on 19 Dec 2009 #permalink