Warbler ID, Hainan, China (1 Viewer)

[Hainan on the fly]

This looks like Hartert's Leaf Warbler to me. Combination of double yellow wingbar, wide and long supercilium, pale legs and long orangish beak seem to separate it from other local species. As always, please let me know if I should be looking a different species or if I've missed something.

Thanks,

Brian

 

[KenM]

You’ll need other opinions Brian, but it certainly appears to compare with Hartert’s Leaf Warbler imo.

Cheers

 

[Grahame Walbridge]

The extent and strength of yellow saturation including supercilium, face, throat, breast and under tail coverts looks good for nominate (goodsoni) Hartert's IMO. It looks too bright and heavy-billed for Kloss's Leaf Warbler. That said, I have no personal experience of Hartert's so hopefully John will confirm.

Grahame

 

[bouncerhero]

I don't live in China and I don't know about China's warblers, but I agree. When I look up Grahame's and KenM's opinon, it matches closely to a Hartert’s Leaf Warbler.

 

[Hainan on the fly]

The extent and strength of yellow saturation including supercilium, face, throat, breast and under tail coverts looks good for nominate (goodsoni) Hartert's IMO. It looks too bright and heavy-billed for Kloss's Leaf Warbler. That said, I have no personal experience of Hartert's so hopefully John will confirm.

Grahame

Thanks Grahame. I did look at Kloss’s as well, which I don’t believe is as common in Hainan. I think your separation descriptions make sense. I also noticed that the legs of my bird appear to be more dull that what I saw on KLW. Anyways, I always appreciate your input and find it very helpful as I'm learning.

Cheers,

Brian

 

[johnallcock]

I agree that this looks like it's Hartert's. It has fairly extensive yellow below, long bill, double wing bar and seems to have a rear crown stripe (although this isn't clear).

I don't have a lot of experience with Kloss's to compare. But as Grahame suggests, I'd expect them to look smaller-billed and to be whiter on the underparts.

Behaviour is often a good clue, that you can't pick up from the photos - Kloss's would normally be in the smaller twigs and leaves whereas Hartert's is usually among the larger branches, and often shows the 'nuthatch' behaviour of feeding on the sides of main trunks. But be warned that this isn't always the case, and Hartert's does sometimes feed in the canopy.

The exact extent of yellow on Hartert's is fairly variable - in my experience, most individuals of nominate goodsoni are brighter yellow below than this bird but there seems to be a lot of intergrades with whiter fohkiensis and it's not too unusual to have this combination of yellow face/supercilium, throat, breast and undertail coverts but whiter belly. I think that more work is needed on the regional variation between goodsoni and fohkiensis, and it's possible these may really be extremes of a cline rather than clear-cut subspecies.

 

[Hainan on the fly]

I agree that this looks like it's Hartert's. It has fairly extensive yellow below, long bill, double wing bar and seems to have a rear crown stripe (although this isn't clear).

I don't have a lot of experience with Kloss's to compare. But as Grahame suggests, I'd expect them to look smaller-billed and to be whiter on the underparts.

Behaviour is often a good clue, that you can't pick up from the photos - Kloss's would normally be in the smaller twigs and leaves whereas Hartert's is usually among the larger branches, and often shows the 'nuthatch' behaviour of feeding on the sides of main trunks. But be warned that this isn't always the case, and Hartert's does sometimes feed in the canopy.

The exact extent of yellow on Hartert's is fairly variable - in my experience, most individuals of nominate goodsoni are brighter yellow below than this bird but there seems to be a lot of intergrades with whiter fohkiensis and it's not too unusual to have this combination of yellow face/supercilium, throat, breast and undertail coverts but whiter belly. I think that more work is needed on the regional variation between goodsoni and fohkiensis, and it's possible these may really be extremes of a cline rather than clear-cut subspecies.

Thanks John! I find the tips on behavior particularly interesting. This bird was kind of bouncing around in bamboo and some small trees with sparse leaves which given your comments seems to further support Hartert's.

Cheers,

Brian