Pale-legged/Sakhalin Leaf Warbler Phylloscopus tenellipes/borealoides, Yangkou, Rudong, Jiangsu, China, 1 May 2014. Some authors note minor differences in plumage and bare parts, but the features overlap, making non-singing Pale-legged and Sakhalin virtually indistinguishable in the field. The species pair is distinguishable from other leaf warblers by their very pale, pink legs. The species pump the tail steadily and often cling to tree trunks, somewhat like a nuthatch. Pale-legged breeds in the Russian Far East and northeast China; Sakhalin breeds on Sakhalin Island and in Japan.

Sakhalin & Pale-legged Leaf Warbler, Singing Together

Today, 5 May 2016, I got my first-ever record of Sakhalin Leaf Warbler. The bird was singing on the tiny island at the little central pond (31.224111, 121.414194) at Zhongshan Park, Shanghai. Singing nearby was Pale-legged Leaf Warbler. These lookalike species were two of the seven species of passage migrant I noted, the others being Ashy Minivet, Yellow-browed Warbler, Eastern Crowned Warbler, at least one Turdus sp. that was not Chinese Blackbird, Asian Brown Flycatcher, Narcissus Flycatcher, and Mugimaki Flycatcher.

I saw a Pale-legged or Sakhalin Leaf Warbler, pulled out my iPhone, and played back a recording of Pale-legged. I got no response. I played Sakhalin for a while, got no response, then stopped. I knew not to walk away, but wait. As Shanghai is outside the breeding range of both species, their urge to sing may not be strong, but it is May and the testosterone is flowing. A response may come after a lag.

Pale-legged/Sakhalin Leaf Warbler Phylloscopus tenellipes/borealoides, Yangkou, Jiangsu, 1 May 2014. As is usually the case, because the bird in this photo was not singing, I was unable to identify it beyond the level of Pale-legged/Sakhalin. On 5 May 2016, I had the good luck of finding not one, but both members of the Pale/Sak species pair singing, and thus identifiable to species level. I was able to make the double ID of these poorly known East Asian species in a busy park in the middle of Shanghai. Photo taken from archives of craigbrelsford.com.
Pale-legged/Sakhalin Leaf Warbler Phylloscopus tenellipes/borealoides, Yangkou, Jiangsu, 1 May 2014. As is usually the case, because the bird in this photo was not singing, I was unable to identify it beyond the level of Pale-legged/Sakhalin. On 5 May 2016, I had the good luck of finding not one, but both members of the Pale/Sak species pair singing, and thus identifiable to species level. I was able to make the double ID of these poorly known East Asian species in a busy park in the middle of Shanghai. Photo taken from archives of craigbrelsford.com.

I was standing at the edge of the little pond, admiring Narcissus Flycatcher. My brain was barely registering the normal background noise being made by Japanese Tit, Light-vented Bulbul, Chinese Blackbird, Chinese Grosbeak, caged Chinese Hwamei, and old folks practicing qigong. Suddenly from the din came an anomalous sound. I trained my attention to the high-pitched whistle. Sakhalin! My playback had apparently been heard and had attracted a Sakhalin to the tree on the island closest to me on the “mainland.” I glimpsed the bird but saw nothing in its plumage or bare parts to tell it from Pale-legged. In the field, the only reliable element separating the two species is song. Sakhalin makes a three-note whistle, very different from the cricket-like trill of Pale-legged. The three-note whistle is exactly what I was hearing.

After a few minutes, the singing stopped, and then, as if on cue, the trill of Pale-legged surged out from the foliage. I again played back Pale-legged recordings and this time got an immediate and very strong response. Making the “tink” call, a Pale-legged flew to my side of the pond and lingered in trees near me. The tink is apparently similar to that of Sakhalin and therefore not a reliable separator. But soon the tink was followed by another trill, and I knew I was looking at Pale-legged.

What luck! There I was, in the middle of Earth’s largest city, hearing the songs of two East Asian leaf warblers, one of them (Sakhalin) little-known. Does urban birding get any better than this?

My trusty Olympus DM-650 sound recorder, the device I used to record Sakhalin Leaf Warbler and Pale-legged Leaf Warbler. In May, the height of migration season, my sound recorder is like the American Express card: 'Don't Leave Home Without It!'
My trusty Olympus DM-650 sound recorder, the device I used to record Sakhalin Leaf Warbler and Pale-legged Leaf Warbler. In May, the height of migration season, my sound recorder is like the American Express card: ‘Don’t Leave Home Without It!’

I sound-recorded both species. In all, one can hear the din from a busy inner-city park. In the first of the two song fragments of Sakhalin Leaf Warbler, among the species heard in the background is Ashy Minivet.

Sakhalin Leaf Warbler, Song Fragments 1/2 (00:51; 2.8 MB)

Sakhalin Leaf Warbler, Song Fragments 2/2 (00:36; 2.2 MB)

Pale-legged Leaf Warbler, Trill (00:03; 922 KB)

Pale-legged Leaf Warbler, Tink (00:15; 1.4 MB)

Thanks to Jan-Erik Nilsén, Jonathan Martinez, and Jason Loghry for their help in today’s project.

List 1 of 1 for Thurs. 5 May 2016 (17 species). Birds noted at Zhongshan Park (Zhōngshān Gōngyuán [中山公园]; 31.221888, 121.420066), urban green space in Shanghai, China. Cloudy; low 19° C, high 24° C. Visibility 3 km. Wind SSE 18 km/h. PM2.5 AQI: 132 (unhealthful). Sunrise 05:05, sunset 18:37. THU 05 MAY 2016 06:10-08:15. Craig Brelsford.

Feral Pigeon (Rock Dove) Columba livia 8
Spotted Dove Spilopelia chinensis 4
Ashy Minivet Pericrocotus divaricatus 8
Japanese Tit Parus minor 5 (2 begging fledglings)
Light-vented Bulbul Pycnonotus sinensis 25
Yellow-browed Warbler Phylloscopus inornatus 7 (1 singing)
Pale-legged Leaf Warbler P. tenellipes 1 singing
Sakhalin Leaf Warbler P. borealoides 1 singing
Eastern Crowned Warbler P. coronatus 2
Chinese Blackbird Turdus mandarinus 17 (4 fledglings)
Turdus sp. 4 making tseep call high in trees
Oriental Magpie-Robin Copsychus saularis 1
Asian Brown Flycatcher Muscicapa latirostris 2
Narcissus Flycatcher Ficedula narcissina 1
Mugimaki Flycatcher F. mugimaki 1
Eurasian Tree Sparrow Passer montanus 30
Chinese Grosbeak Eophona migratoria 5

Featured image: Pale-legged/Sakhalin Leaf Warbler Phylloscopus tenellipes/borealoides, Yangkou, Rudong, Jiangsu, China, 1 May 2014. Some authors note subtle differences in plumage and structure, but the features overlap, making non-singing Pale-legged and Sakhalin virtually indistinguishable in the field. The species pair is distinguishable from other leaf warblers by their very pale, pink legs. The species pump the tail steadily and often cling to tree trunks, somewhat like a nuthatch. Pale-legged breeds in the Russian Far East and northeast China; Sakhalin breeds on Sakhalin Island and in Japan. Photo by Craig Brelsford and taken from archives of craigbrelsford.com.

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Craig Brelsford

Craig Brelsford lives in Shanghai, where he runs shanghaibirding.com and studies Chinese at the Shanghai University of Engineering Sciences. Craig is the top-ranked (by species) eBirder in China, having noted more than 930 species. He is, in addition, the top-ranked eBirder in Shanghai, with more than 320 species. A 1993 graduate of the University of Florida, Craig was an award-winning newspaper editor in the United States for 10 years. In 2002, Craig earned the diplôme d'études spécialisées en sciences de gestion from the University of Liege in Belgium. Craig has lived in Shanghai since 2007.

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