Phylloscopus warblers, either one of the joys of Sichuan or a constant pain in the neck! These species are not adequately dealt with in any existing field guide, though there are some online resources that cover the warblers of south-west China, for example, Per Alström‘s overview is essential reading. So out of the chaos of wingbars, supercilia and a multitude of shades of olive, I have tried to create order in the species that we recorded.
There are over 25 species of phylloscopus warbler frequently recorded in Sichuan and they are all very similar: the size and colour of a leaf, but so much more mobile. They advertise and recognise each other through vocalisations, so it makes sense that we should do the same. The good news: in order to simplify the field identification of so many very similar species I have grouped the species of phylloscopus warbler that we saw into 5 basic types. Being a UK based birder I have used the following warbler species as headline species, the species within each type share some plumage characteristics:
Pallas’s Warbler types
Hume’s Warbler types
Greenish Warbler types
Eastern Crowned Warbler types
Dusky Warbler types
This model is not perfect, but it gave me a handle on getting to grips with this difficult group and may be useful for those planning to visit Sichuan. I have also embedded recordings of the song of each species from the fabulous Xeno Canto website. The bad news: I have illustrated this blog post with my own pictures. Don’t want to make it too easy for you….
1. Pallas’s Warbler types: Bright supercilium+ bright medial crown stripe, double wing bars, dark tertials and a pale rump. The whole shebang.
Sichuan Leaf Warbler Phylloscopus forresti
Sichuan Leaf Warbler: a muted Pallas’s Warbler. It has the rump and the seven stripes, but none of the vivid greens or yellows of Pallas’s Warbler. The song is a series of rapid high pitched trills, each ending with a Eurasian Wren-like rattle:
[Frank Lambert, XC111060. Accessible at www.xeno-canto.org/111060.]
Chinese Leaf Warbler Phylloscopus yunnanensis
Even duller than Sichuan Leaf Warbler! A Pallas’s Warbler type, but with a completely different song to Sichuan Leaf or Pallas’s. One of my favourite sounds from Jiuzhaigou National Park, Chinese Leaf Warbler sounds like a tiny sewing machine rattling away, quite Locustella-like.
[Oscar Campbell, XC285252. Accessible at www.xeno-canto.org/285252]
Buff-barred Warbler Phylloscopus pulcher
Not really so Pallas’s Warbler-like in real life, though it shares many features. However, the crown is grey, contrasting with the green mantle; the bright buff greater covert bar stands out and the pale rump is present. The white outer tail feathers are distinctive.
[Frank Lambert, XC161371. Accessible at www.xeno-canto.org/161371]
2. Hume’s Warbler types: Bright supercilium, faint (at best) medial crown stripe; double wingbars, dark tertials and no rump patch.
Hume’s Warbler Phylloscopus humei mandellii
The Hume’s Warblers in south west China are mandellii rather than humei. We heard calling rather than singing birds.
[Frank Lambert, XC113239. Accessible at www.xeno-canto.org/113239]
3. Greenish Warbler types: Bright supercilium, but no real medial crown stripe; double wingbars, greenish tertials and no rump patch.
Greenish Warbler Phylloscopus trochiloides
One of commoner leaf warblers, we found them at a number of different sites.
[Mike Nelson, XC266546. Accessible at www.xeno-canto.org/266546]
Large-billed Warbler Phylloscopus magnirostris
The long bill can be distinctive in the field. Thanks to James Eaton on Birdforum for noting the weak wing bars and mottled ear coverts of this species. A common, easily recognisable song: a single, followed by two double, melancholy descending notes:
[Guy Kirwan, XC324805. Accessible at www.xeno-canto.org/324805]
4. Eastern Crowned Warbler types: Larger warblers with a bright supercilium + medial crown stripe, double wings bars, greenish tertials, no pale rump.
Emei Leaf Warbler Phylloscopus emeiensis
We only saw this species in Longcanggou. Can flick both wings simultaneously (see Kloss’s and Claudia’s Leaf Warblers, below). The song is a distinctive shimmering trill:
[Oscar Campbell, XC282711. Accessible at www.xeno-canto.org/282711]
Kloss’s Leaf Warbler Phylloscopus ogilviegranti disturbans
Very similar to both Emei Leaf and Claudia’s Leaf. Flicks both wings simultaneously (see Claudia’s Leaf Warbler, below). The song is a pleasant burst of notes, delivered with even spacing:
[Mike Nelson, XC267134. Accessible at www.xeno-canto.org/267134]
Claudia’s Leaf Warbler Phylloscopus claudiae
One of the commoner leaf warblers. Has the habit of flicking a single wing (see picture) or alternates flicking one wing and then the other. The song is a rapid burst of high pitched notes, longer and faster than Kloss’s Warbler:
[Frank Lambert, XC183391. Accessible at www.xeno-canto.org/183391]
Sulphur-breasted Leaf Warbler
A lower altitude species, only seen in Tangjihae National Park. A feast of strong head stripes, recalling Worm-eating Warbler, but much more yellow! Song consists of a few well spaced bursts of liquid notes, sung at a moderate pace:
[Nick Athanas, XC23034. Accessible at www.xeno-canto.org/23034]
5. Dusky Warbler types: Buff warblers, with an obvious supercilium, plain wings and plain rump.
Dusky Warbler Phylloscopus fuscatus fuscatus
[Frank Lambert, XC113518. Accessible at www.xeno-canto.org/113518]
Yellow-streaked Warbler Phylloscopus armandii
The Radde’s Warbler sister species that we await to discover one autumn in the UK! Seen in scrub in lower level river valleys.
[Mike Nelson, XC191320. Accessible at www.xeno-canto.org/191320]
Alpine Leaf Warbler Phylloscopus occisinensis
A high altitude species, seen foraging for insects in snow covered bushes at Balangshān at over 3000m.
[Yong Ding Li, XC144887. Accessible at www.xeno-canto.org/144887]
Buff-throated Warbler Phylloscopus subaffinis
We only encountered this species in Longcanngou. A simple repeating song:
[Frank Lambert, XC187023. Accessible at www.xeno-canto.org/18702]
One of the highlights of birding the forests of Sichuan was the constant presence of Leaf Warblers. To stand on, for example, the hills above Wolong (below) and scan through the trees picking up multiple phylloscopus warblers was a fantastic, if technically challenging, experience:
My advice would be go to Sichuan in Spring when the phylloscopus warblers are singing. Otherwise you will have to leave even more species unidentified than I had to: good luck!