White-eye identification in Taipei (1 Viewer)

[Limeatine]

I have a White-eye identification query. The picture is from a few weeks ago (mid May 2024) in central Taipei, near Da An Forest Park. It seems as though it's either a Warbling White-eye (Zosterops japonicus) or a Swinhoe's White-eye (Zosterops simplex), but all the suggestions on how to tell them apart seem far too subtle to me. Any help would be much appreciated!

 

[redpandacat]

As no-one else has replied I'll give it a shot. Happy for others to weigh-in.

The expected subspecies seem to be Zosterops japonicus japonicus and Zosterops simplex simplex. Swinhoe's is much more commonly reported but Warbling is possibly overlooked. Swinhoe's (e.g. here and here) tends to have lighter yellow chin as well as above the beak and lores (when compared with the adjacent areas). Warbling (e.g. here and here) tends to be uniformly coloured across these areas and the adjacent areas. It also seems that Warbling sometimes has a brownish-reddish tinge to the belly whereas Swinhoe's is more often just greyish or white - I'm not certain whether presence of this tinge is diagnostic but presence seems to favour Warbling over Swinhoe's (at least when comparing these subspecies).

Looking at your photos there's contrast between chin and cheek (say) and also paler above beak compared with crown (say). Thus I'd suggest Swinhoe's.

 

[Limeatine]

Thank you very much! It does seem like Swinhoe's is more commonly reported in northern Taiwan (or at least around Taipei), and your argument makes sense, so it seems very probable that is what it is.