Samut Prakan, Bangkok earlier this morning (3 Viewers)

[Bertus]

I agree the wagtail is first winter Yellow. I'm not sure whether you tell if it's Western thunbergi or Eastern macronyx, which both have a dark grey head and little or no supercilium. I guess macronyx is more likely in Bangkok?

Dear John, I am a little surprised. I watched wagtails with clear yellow often in Thailand and followed Robson's guide to whether M. flava (Yellow Wagtail) or M. Cinerea (Grey Wagtail). I was convinced that they were usually Grey Wagtails cause of the grey on the back. Robson maps show that both species are found in all the country. eBird however shows no obs of M. flava in Thailand.
But eBird shows indeed M. tschutschensis (Eastern Yellow Wagtail) (https://ebird.org/species/eaywag/) and a map with many obs but also Motacilla tschutschensis macronyx (Eastern Yellow Wagtail subspecies) in addition and a map with less obs in Thailand (https://ebird.org/species/weywag9). Who is right, Robson or eBird? The name Yellow Wagtail is confusing since that should be whether Eastern or Western. And eBird shows that most of them is not macronyx but just M. tschutschensis. Robson does not mention any of these. How could Robson show a map with M. flava obs in all Thailand then?
When I look better at eBird's pics it seems that the Manchurian has some white in the supercilium, is that correct? Tnx for advice

 

[Bertus]

The swallow could be one of those. Wire-tailed??

https://birdcount.in/identifying-swallows/

Hi 01101001, not 007, I reply here since your last comment came by email but not in the thread here under. Tnx for your help. Not split in two species? Probably. But why? Robson describes a M. flava even as thunbergi, which does not exist in Thailand. We call that a Northern Wagtail in Holland (https://ebird.org/species/weywag2). According to eBird the species found in most of Thailand should be named M. tschutschensis and I guess that is what Robson meant and shows drawings of. Avibase states that ssp angarensis or plexa, that Robson mentions too as a ssp, are two of five ssp of the Eastern Wagtail. Not including macronyx. On this page (Motacilla tschutschensis macronyx (Eastern Yellow Wagtail (macronyx)) - Avibase) however the ssp M. thunbergi macronyx is suddenly called Grey Wagtail, while Robson put that under Yellow Wagtail. Difficult to follow. Where should I look for the best nomenclature youy think? Tnx again

 

[johnallcock]

Dear John, I am a little surprised. I watched wagtails with clear yellow often in Thailand and followed Robson's guide to whether M. flava (Yellow Wagtail) or M. Cinerea (Grey Wagtail). I was convinced that they were usually Grey Wagtails cause of the grey on the back. Robson maps show that both species are found in all the country. eBird however shows no obs of M. flava in Thailand.
But eBird shows indeed M. tschutschensis (Eastern Yellow Wagtail) (https://ebird.org/species/eaywag/) and a map with many obs but also Motacilla tschutschensis macronyx (Eastern Yellow Wagtail subspecies) in addition and a map with less obs in Thailand (https://ebird.org/species/weywag9). Who is right, Robson or eBird? The name Yellow Wagtail is confusing since that should be whether Eastern or Western. And eBird shows that most of them is not macronyx but just M. tschutschensis. Robson does not mention any of these. How could Robson show a map with M. flava obs in all Thailand then?
When I look better at eBird's pics it seems that the Manchurian has some white in the supercilium, is that correct? Tnx for advice

The taxonomy of yellow wagtails is slightly confusing.

Eastern and Western Yellow Wagtails were previously combined into one species, Yellow Wagtail Motacilla flava, with many subspecies. If your Robson guide dates to this time, it will only show Yellow Wagtail.

Most checklists now treat Eastern Yellow Wagtail M. tschutschensis as a separate species, with three subspecies: tschutschensis, macronyx and taivana. All three of these subspecies should occur in Thailand. The other subspecies are treated in most checklists as being part of Western Yellow Wagtail M. flava, including the subspecies thunbergi. Subspecies thunbergi (Western) is essentially identical to subspecies macronyx (Eastern), so in my earlier reply I said that it was one of these two subspecies, but I couldn't be sure which one. But it is probably macronyx - I don't think thunbergi or any other Western Yellow Wagtail subspecies occurs regularly in Thailand (but I'm not based in Thailand, so I am not familiar with local status).

As you've mentioned some authorities (eg the Dutch Birding checklist) consider there to be more species in this complex, including a separate species for M. thunbergi.

Note that most checklists do not treat subspecies angarensis and plexa as being valid subspecies - these are usually considered to represent variation in either macronyx or thunbergi, or an intergrade between these and another taxon. As you mentioned, some macronyx (Manchurian) do have a small white spot in the supercilium, but this is not consistent and is probably just individual variation.

The maps in eBird can be set up show either Eastern Yellow Wagtail (this approach includes all subspecies and any birds for which the observer didn't report the subspecies) or only subspecies macronyx (this approach includes only those records that the observer reported as this subspecies, so will always show fewer records than the other approach).

I hope this clarifies slightly. I know it is a very confusing situation!

 

[Bertus]

The taxonomy of yellow wagtails is slightly confusing.

Eastern and Western Yellow Wagtails were previously combined into one species, Yellow Wagtail Motacilla flava, with many subspecies. If your Robson guide dates to this time, it will only show Yellow Wagtail.

Most checklists now treat Eastern Yellow Wagtail M. tschutschensis as a separate species, with three subspecies: tschutschensis, macronyx and taivana. All three of these subspecies should occur in Thailand. The other subspecies are treated in most checklists as being part of Western Yellow Wagtail M. flava, including the subspecies thunbergi. Subspecies thunbergi (Western) is essentially identical to subspecies macronyx (Eastern), so in my earlier reply I said that it was one of these two subspecies, but I couldn't be sure which one. But it is probably macronyx - I don't think thunbergi or any other Western Yellow Wagtail subspecies occurs regularly in Thailand (but I'm not based in Thailand, so I am not familiar with local status).

As you've mentioned some authorities (eg the Dutch Birding checklist) consider there to be more species in this complex, including a separate species for M. thunbergi.

Note that most checklists do not treat subspecies angarensis and plexa as being valid subspecies - these are usually considered to represent variation in either macronyx or thunbergi, or an intergrade between these and another taxon. As you mentioned, some macronyx (Manchurian) do have a small white spot in the supercilium, but this is not consistent and is probably just individual variation.

The maps in eBird can be set up show either Eastern Yellow Wagtail (this approach includes all subspecies and any birds for which the observer didn't report the subspecies) or only subspecies macronyx (this approach includes only those records that the observer reported as this subspecies, so will always show fewer records than the other approach).

I hope this clarifies slightly. I know it is a very confusing situation!

Great reply, clear, lots of answers, tnx a lot, regards

 

[johnallcock]

Also, note that Grey Wagtail Motacilla cinerea is a completely different species. This is usually found along streams, not in marshes, and can be identified because it has pale pink legs, yellow undertail, broad white wingbars (in flight) and a different call. You may have seen this species in Thailand.

Young Eastern Yellow Wagtails have a grey back in their first winter, so can be confused with Grey Wagtail based only on this feature. It is useful to also consider the other features (leg colour, call, habitat, etc) as part of the identification process.

 

[Bertus]

Yes I am still sorting out years of pics and I will come up with records of wagtails asa I find them. Very helpful, great...