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Water rail sp in Mongolia (1 Viewer)

Liebzi

New member
Hi,

What will you call this water rail? Eastern or western water? Seen in Western Mongolia 4th of September 2019. First thoughts and fellings were Brown-cheeked Rail (Eastern) due to the very brownish look. Headpattern looks great for Brown-cheeked too with a strong white supercilium in front of the eye and a very clean white throat. Doesn't have the western water rail's dark greyish blue face color. Also, the breast appears to be washed brownish.

For me, it looked great for a Brown-cheeked Rail at the moment but I have realized after looking at the photos that the bird shows very clean white undertail coverts without any barring at all which should only occur on Western. The question is then - can Eastern show undertail coverts like that or is the undertail coverts the most reliable field mark to separate Brown-cheeked Rail and Water Rail?? I still have a feeling that we are dealing with an Brown-cheeked Rail (Rallus Indicus)

Best regards,

Anton
 

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Valéry Schollaert

Respect animals, don't eat or wear their body or s
I'm a bit confused with you names. AFAIK, Rallus indicus is Eastern Water Rail (or Brown-cheeked as a synonym), the only Rallus rail supposed to occur in Mongolia. Did I miss something ?

I've no experience of Eatern Water Rail, but you bird looks like Western Water Rail. I might be a overlooked visitor to the West ?

Interesting post, for sure.
 

DMW

Well-known member
I can't give a definitive answer, but the bill looks very robust for (Western) Water Rail, and seems a better match for Brown-cheeked.
 

johnallcock

Well-known member
Do you have any more photos of the bird, perhaps showing it from the side?

Besides the head pattern and undertail, there also seem to be differences between the two species in the strength of streaking in the upperparts and in the black/white patterning on the flanks, which are not visible on these photos. Some plumage features are also affected by the age of the bird.

This is an interesting-looking bird. I would say that the head pattern is not as obvious as I'd expect on Brown-cheeked (ear coverts are no very brown, lores are not very dark) and although there is a slight brown wash on the breast, this is not as obvious as I would normally expect on Brown-cheeked. The streaking seems very weak on the crown and breast sides compared to the usual pattern for Brown-cheeked. Combined these give it a much cleaner face pattern than I would normally expect on Brown-cheeked.

Juvenile (western) Water Rails are browner than adults, and often show a white supercilium and throat. The bill is also often shorter than on adults, because it may not be fully grown.
https://www.alamy.com/western-water...aquaticus-greece-juvenile-image211613947.html

The range map in HBW shows Water Rail occurring in the extreme west of Mongolia, and extends east almost as far as Baikal. It is therefore perhaps more likely than Brown-cheeked in the far west of Mongolia. It has also occurred as a vagrant at several locations in far east Asia.

So on balance, I think the most likely explanation is that your bird is a juvenile (Western) Water Rail, but if you have more photos these might be informative.
 

rollingthunder

Well-known member
England
The bird does look to have a thick driller but that could be the two-toned appearance and/or individual variation. I have no experience other than Common Water Rail and it looks like a youngish bird. I do not know the moult pattern so will refrain from juvenile or 1st-Winter and leave it to those with knowledge of such things:t:

Laurie -
 

MacNara

Well-known member
Japan
I can't say which of these species this bird is - it's a juvenile whichever it is.

I'd just like to give a few comments which I hope may be of interest to some people looking at this thread.

Background: Where I live in Nara, near Osaka in west-central Honshu, Japan, 'Eastern Water Rail' are fairly common wintering birds (although the number of individual birds in one area is, of course, small). Near my house, in a very small reedbed (in a park) birds often come out into the open in February or March, and you can sometimes get pictures of two birds together. (Ruddy Crake are also found in the same spot.)

1. The Rails arrive here for the winter in late October or November. But I have never knowingly seen a juvenile-looking bird.

2. As Liebzi says, the undertail coverts are supposed to be white on the Western Water Rail and barred on the Eastern (aka Brown-eared), I have attached two photos (same bird), one of which shows a bird in almost the same posture as Liebzi's photo showing the undertail coverts, and you can see the difference from Liebzi's bird.

3. Unfortunately (I suppose because they don't breed here) none of my books, either in English or Japanese, show the juvenile undertail coverts. Handbook of Birds of the World is not very informative on these two species, either, in my opinion. But Liebzi's bird looks very white, and I would be surprised if Eastern juvenile was so white.

4. I have three different Japanese-language guides to (all) the birds of Japan published between 2014 and 2017, by well-known and respected authors, and none of them splits Eastern from Western (all give just Rallus aquaticus; no indicus). It has to be said that the brown cheek patch is not always that obvious, and not a particularly clear feature - on my first photo it's obvious but not extreme and in the other it's much less obvious. Why would that not be just a racial variation, not a species variation? On the other hand, the barred versus white undertail covert difference on adults (at least) is very striking (I'm judging Western on photos as I have never seen one myself).

5. Unlike my Japanese-language books, Mark Brazil's 'Birds of East Asia' from 2009 does recognise the split and has an entry for 'Eastern Water Rail', Rallus indicus (only, no aquaticus). Unfortunately, the illustration (adult, no juvenile) clearly shows snow-white undertail coverts; maybe the publisher re-purposed a painting of unsplit Water Rail by painting a smudge on the face and leaving the rest unchanged. (I don't have Brazil's more recent Birds of Japan - would anyone who does have it like to look and see if this error has been corrected?)
 

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johnallcock

Well-known member
MacNara's pictures are very useful for comparison here. As well as the undertail colour, compare the darkness and the strength of streaking on the crown and the sides of the breast. The lores are much darker and the ear coverts and breast are much browner than the OP bird, so that from behind the grey is restricted to the supercilium and a small area on the throat - this is fairly typical of Brown-cheeked.

MacNara's bird is probably an adult, judging by the brightness of the bill and the lack of white in the supercilium - remember that a young bird would be even duller and browner than this.


These two species are actually very different (probably more distinct than some of the American Rallus). This distinctiveness is probably confused by the fact that they used to be lumped, and not helped by the continued use of the name 'Eastern Water Rail' in some lists.

I'm surprised that your recent field guides don't split them, especially as Water Rail is a potential vagrant to Japan, and it would be useful to ensure that observers know what to look for. The split is well supported morphologically and genetically.

I agree that the illustration in Birds of East Asia is an adapted (Western) Water Rail - besides the undertail, this bird differs from Brown-cheeked in head pattern, breast pattern, flank pattern and bill length.
 

MacNara

Well-known member
Japan
I'm surprised that your recent [Japanese-language] field guides don't split them, especially as Water Rail is a potential vagrant to Japan, and it would be useful to ensure that observers know what to look for. The split is well supported morphologically and genetically.

Well, Mark Brazil's book covers a larger area and has only 'Eastern' and no 'Western'. So, presumably Brazil didn't think 'Western' was likely to come into the area he covered. And strangely, the Japanese-language books that I mention include not just birds which have been reported as seen once or twice in Japan over 100 years (but photo evidence is a much more recent thing than many of these sightings), but also a lot (maybe as many as 100) which have never been seen in Japan, but which the authors claim might be seen sometime soon (mainly, I think, a sales gimmick to up the number of birds shown on the cover of the book) - one of the guides from an extremely reputable bird expert whom I have met, has gone from 570 species for the previous edition of his book to 670 in the current (2014) edition - but he also doesn't split Water Rail.

I agree that the illustration in Birds of East Asia is an adapted (Western) Water Rail - besides the undertail, this bird differs from Brown-cheeked in head pattern, breast pattern, flank pattern and bill length.

Yes, this seems odd, and makes me wonder about some of the other illustrations in 'Birds of East Asia' which I have thought 'not quite right'.
 

DMW

Well-known member
This has been a very informative thread. Is there any (possibly age-related) overlap in the undertail pattern between the two species? Looking at photos online, the extent of undertail streaking seems quite variable in Brown-cheeked, from seemingly rather limited to very heavy (as in McNara's excellent photos).

Perhaps also worth mentioning that vocalisations are quite distinct.
 

Larry Sweetland

Formerly 'Larry Wheatland'
Yes, IOC names are clear, I think OP names are not that clear, like if he is asking how to separate Brown-cheeked from Eastern Rail, which is the same bird. ;)

If you reread the OP, you'll see he's talking about Eastern/Brown-cheeked cf Western. He's just used both common names for R. indicus scattered around the post
 

MJB

Well-known member
For info, i recorded Western Water Rail in mid-Mongolia in May this year, as well as seeing it in the same place two years ago but without documentation. See the eBird checklist at

https://ebird.org/checklist/S58136449


I was kinda hoping for Brown-cheeked!

BirdLife Datazone maps indicate that Western Water Rail is a regular summer breeder in westernmost Mongolia. Also Eastern Water Rail likewise breeds in north-central Mongolia (adjoining a much larger area of Russia to the north and east) and just into easternmost Mongolia from northwest China. Given the relative paucity of observers, it seems quite likely that outlier Western Water Rail populations might regularly or sporadically occur south to Khar Us Lake and east to Khovsgol Lake.
MJB
 

johnallcock

Well-known member
Well, Mark Brazil's book covers a larger area and has only 'Eastern' and no 'Western'. So, presumably Brazil didn't think 'Western' was likely to come into the area he covered. And strangely, the Japanese-language books that I mention include not just birds which have been reported as seen once or twice in Japan over 100 years (but photo evidence is a much more recent thing than many of these sightings), but also a lot (maybe as many as 100) which have never been seen in Japan, but which the authors claim might be seen sometime soon (mainly, I think, a sales gimmick to up the number of birds shown on the cover of the book) - one of the guides from an extremely reputable bird expert whom I have met, has gone from 570 species for the previous edition of his book to 670 in the current (2014) edition - but he also doesn't split Water Rail.

I think Birds of East Asia was published at around the time of the split, so it was probably a last minute change. And I think it was assumed at that time that Western didn't come this far east. I remember being surprised when I found the first HK record back in December 2006 (documented with ID notes on pp 232-239 here: https://www.hkbws.org.hk/web/chi/documents/bird_report/2007-08_birdreport_protected.pdf), because it seemed so far out of the published range. But there has also been an earlier HK sighting uncovered when reviewing records. There are also sightings in Beijing (https://birdingbeijing.com/2012/02/17/eastern-or-western-water-rail/) and Korea (http://www.birdskorea.org/Birds/Identification/ID_Notes/BK-ID-Western-Water-Rail.shtml) and I think elsewhere in China. So I would say it is a very likely vagrant to Japan.


Yes, this seems odd, and makes me wonder about some of the other illustrations in 'Birds of East Asia' which I have thought 'not quite right'.

There are a few errors (Lesser Sand Plover is another one that sticks in my mind, largely because of my interest in the species) but overall I still think it's a useful book to cover the region.
 

johnallcock

Well-known member
This has been a very informative thread. Is there any (possibly age-related) overlap in the undertail pattern between the two species? Looking at photos online, the extent of undertail streaking seems quite variable in Brown-cheeked, from seemingly rather limited to very heavy (as in McNara's excellent photos).

Perhaps also worth mentioning that vocalisations are quite distinct.

I'm not aware of any overlap. Although the extent of the white fringes varies a bit in Brown-cheeked, I think they always have black centres to the feathers. Note that the difference in pattern is not just on the undertail coverts, but also extends along the central underparts as far forward as the legs, as can be seen by comparing Liebzi's photo with MacNara's.


For info, i recorded Western Water Rail in mid-Mongolia in May this year, as well as seeing it in the same place two years ago but without documentation. See the eBird checklist at

https://ebird.org/checklist/S58136449


I was kinda hoping for Brown-cheeked!

BirdLife Datazone maps indicate that Western Water Rail is a regular summer breeder in westernmost Mongolia. Also Eastern Water Rail likewise breeds in north-central Mongolia (adjoining a much larger area of Russia to the north and east) and just into easternmost Mongolia from northwest China. Given the relative paucity of observers, it seems quite likely that outlier Western Water Rail populations might regularly or sporadically occur south to Khar Us Lake and east to Khovsgol Lake.
MJB

I suspect that both species are more widespread in Mongolia (and in fact China and Russia) than is currently known. There are not many observers in that area, it's a difficult species to see, and it's probably not a priority for most visiting birders.
 

Frenchy

Well-known member
BirdLife Datazone maps indicate that Western Water Rail is a regular summer breeder in westernmost Mongolia. Also Eastern Water Rail likewise breeds in north-central Mongolia (adjoining a much larger area of Russia to the north and east) and just into easternmost Mongolia from northwest China. Given the relative paucity of observers, it seems quite likely that outlier Western Water Rail populations might regularly or sporadically occur south to Khar Us Lake and east to Khovsgol Lake.
MJB

The Birdlife map shows Western as basically stopping at the Mongolian border, although they almost certainly do breed in western Mongolia, as does Little Crake. Birdlife map Brown-cheeked as entering central Mongolia from the north and extending down to the Khangai mountains. My record was just south of this, so Brown-cheeked would, probably, have been more expected in that area.
 
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