Riparia martins in Malaysia: What are they? (Part 3)

Riparia martin_Malim Nawar_110213_IMG_6142Having looked at the literature and evaluated published identification criteria using photos of ijimae Sand Martin and fohkienensis Pale Martin on the web, I am less optimistic than I was that the two species would ‘stand out’ as being obviously distinct from each other. I think the problem of differentiating them may be as challenging as that of identifying the ‘brown’ swiftlets.

Riparia martin_Malim Nawar_110213_IMG_6030 Riparia martin_Malim Nawar_020213_IMG_5025 Riparia martin_Malim Nawar_020213_IMG_5043 Riparia martin_Malim Nawar_110213_IMG_5641 Riparia martin_Malim Nawar_110213_IMG_5683 Riparia martin_Malim Nawar_110213_IMG_5813 Riparia martin_Malim Nawar_110213_IMG_5989Although they may be useless for identification, what these flight photos show is that the birds were in moult. Almost all had replaced the inner 7-9 primaries, and many had started tail moult, replaced tertials and a varying number of wing coverts. Their state of moult would therefore be consistent, I would have thought, with the Hong Kong Pale Martins, which have mostly completed a full moult by the time they arrive there in April. It’s also worth noting that new feathers are greyer and less warm in tone than the old ones.

Going on what I learned in the previous two posts, my starting point for trying to identify these bird is to look at tarsal feathering.

Riparia martin_Malim Nawar_020213_IMG_4868Riparia martin_Malim Nawar_020213_IMG_4864 Riparia martin_Malim Nawar_020213_IMG_4863Though over-exposed (so don’t read too much into the apparent paleness of the breastband) and distant, this bird, photographed on 2 Feb, had the most extensive tarsal feathering of any bird I saw, a continuous band all the way up the rear tarsus to the tibio-tarsal joint.

Riparia martin_Malim Nawar_110213_IMG_0975 Riparia martin_Malim Nawar_110213_IMG_0966legsIn approximate order of diminishing ‘hairiness’, a few more birds, with a close-up of their tarsi.

Riparia martin_Malim Nawar_110213_IMG_0664 Riparia martin_Malim Nawar_110213_IMG_0664legsRiparia martin_Malim Nawar_110213_IMG_0827 Riparia martin_Malim Nawar_110213_IMG_0827legs Riparia martin_Malim Nawar_110213_IMG_0891Riparia martin_Malim Nawar_110213_IMG_0890legsRiparia martin_Malim Nawar_110213_IMG_0705 Riparia martin_Malim Nawar_110213_IMG_0705legsNot quite so hairy by now, but still following the basic pattern of a continuous fringe up from the hind toe to mid-tarsus.

Riparia martin_Malim Nawar_110213_IMG_0982 Riparia martin_Malim Nawar_110213_IMG_0982legs

At the lower end of the ‘hairiness index’ were birds like this – very sparse and short, but still, the continuous ‘comb’ or ‘fan’ of feathering from base of hind toe to mid-tarsus.

This poses a potentially troublesome question – assuming these are all Pale Martins, how variable is this tarsal feathering? Is it affected by wear? I would expect burrow-nesting birds to do quite a lot of scraping in and out of their nest-holes resting on their tarsi.

Now here’s something interesting!

Riparia martin_Malim Nawar_110213_IMG_0916 Riparia martin_Malim Nawar_110213_IMG_0915legsThis bird lacks the continuous comb of feathers up the tarsus, but instead has two well-developed ‘feather spurs’ on an otherwise bare tarsus, like the Sand Martins here or here perhaps? The other interesting thing is that the legs are dark pink, more this colour (a Sand Martin).

Riparia martin_Malim Nawar_110213_IMG_0926legsI discovered 2 or 3 of these birds, unfortunately only when going through my photos, and there were no other frames to show whether there is a correlation between leg colour and tarsal tuft shape. Still, compare the blackish toes and deep pink tarsi of the bird above with the birds showing fan-like tarsal tufts below.

Riparia martin_Malim Nawar_110213_IMG_0890legs

Hmm – is leg and toe colour significant? Something to check in the future!

Riparia martin_Malim Nawar_110213_IMG_0926

The owner of the dark red legs and blackish toes above.

So – what do I think? All very tentative still, and I’m putting these images and ideas up here to give others the chance to prove me wrong, but … if forced to put my head on the block, I would suggest that the majority of the birds I photographed are Pale Martins, with the possible exception of this one bird which had ‘plume-like’ tarsal tufts, and possibly one or two others which had dark pink legs/blackish toes, which could very well be Sand Martins.

Riparia martin_Malim Nawar_110213_IMG_0722A couple of head-on shots showing the breastband and smudge.

Riparia martin_Malim Nawar_110213_IMG_0759Here’s something else new (for me at least) – dark feather shafts on the belly.

Riparia martin_Malim Nawar_110213_IMG_0759belly

I can recommend a visit to see these martins. Hopefully they’ll stay a month or so longer and we may yet get to see them complete their moult before they leave. Let me know if you need directions.

Oh, and by the way – don’t be fooled by these…

Barn Swallow_Malim Nawar_110213_IMG_5663as someone else has been! These aren’t Pale or Sand Martins, they’re juv Barn Swallows! Note the long bill and different head shape. Brown and white juv Barn Swallows are not so rare in this part of the world, but the plumage variation has not yet found its way into many field guides.

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6 thoughts on “Riparia martins in Malaysia: What are they? (Part 3)

    • Haha – does it mean you should take off Sand Martin from your life list?! If you are seriously asking – it’s your choice entirely. For me, I will only add them once I am sure enough to submit a claim to the RC, which is not yet! Right now, I have Sand/Pale Martin on my list, but not both.

  1. Pingback: Baekryeong Island, May 16 – 26 « Birds Korea Blog

  2. Hi Dave. You might remember discussing these http://www.bubo.org/gallery/list.php?exhibition=26 from south India a few years ago. I concluded at the time that I couldn’t conclude either way – primarily on lack of knowledge of the right field characters and variability! On relative wing length and extensive tarsus feathering it looks like (at least some of) these are Pale Martins. We don’t see riparia martins very often in south India but some more recent sightings (including https://www.youtube.com/watch?v=GrtDezu9pvw) include birds showing shorter wings and no tarsus feathering, which are maybe Sand therefore. Seems unlikely that, with a relative rarity, we should regularly find both species, quite possibly in mixed flocks. Still too early to make conclusions?!

    • Hi Mike, good to hear from you. In reference to your final question, I think so. In order to establish firm criteria for field separation of these two, I think we need to wait for the results of research either at monospecific breeding colonies, or further examination of (large) sets of museum specimens. Recently, Lars Svensson has questioned even whether the differences in measurements and extent of tarsal feathering are diagnostic, so at the moment, we seem to be going backwards rather than forwards! Hopefully they have really diagnostic vocalizations or something!

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