Pale-legged Leaf Warbler/Sakhalin Leaf Warbler, Yangkou, Rudong, Jiangsu, China, 1 May 2014. (Craig Brelsford)

Pale-Sak Calls: An Addendum

In the wake of my recent post on distinguishing Pale-legged Leaf Warbler from Sakhalin Leaf Warbler by call, I have been hoping to find more members of this species pair in Shanghai. On 4 Sept. 2017 at Pudong’s Cape Nanhui, my hopes were fulfilled in a big way. At the Magic Parking Lot (30.884889, 121.968222), not one but both species were calling.

Below, the recordings I made with my Olympus DM-650 pocket recorder. The first Sakhalin recording was made at Microforest 4 (30.953225, 121.959083), 7.7 km north of the Magic Parking Lot on the coastal road. The others were made at the Magic Parking Lot.

Note the higher frequency of the calls of Pale-legged–on average a full kilohertz higher. The difference is discernible by the keen listener, but nothing tells the story better than the spectrograms.

To summarize what I argued in the previous post: The calls, as well as the very distinctive songs, of Pale-legged Leaf Warbler and Sakhalin Leaf Warbler are diagnostic–that is, they differ markedly and consistently and are a reliable basis for an ID. The diagnosability of the calls of the two species has been affirmed by various researchers, among them Yap et al. (2014; Birding Asia 21: 76–81).

Sakhalin Leaf Warbler Phylloscopus borealoides, call, Microforest 4 (30.953225, 121.959083), Cape Nanhui, Pudong, Shanghai, 4 Sept. 2017 (00:02; 528 KB)

Audio spectrogram of call of Sakhalin Leaf Warbler.

Sakhalin Leaf Warbler, call, Magic Parking Lot (30.884889, 121.968222), Cape Nanhui, Pudong, Shanghai, 4 Sept. 2017 (00:07; 1.4 MB)

Audio spectrogram of call of Sakhalin Leaf Warbler.

Pale-legged Leaf Warbler Phylloscopus tenellipes, call, Magic Parking Lot, 4 Sept. 2017 (00:19; 3.7 MB)

Audio spectrogram of call of Pale-legged Leaf Warbler.

Pale-legged Leaf Warbler, call, Magic Parking Lot, 4 Sept. 2017 (00:41; 7.9 MB)

Audio spectrogram of call of Pale-legged Leaf Warbler.

Pale-legged Leaf Warbler, call, Magic Parking Lot, 4 Sept. 2017 (00:10; 2 MB)

Audio spectrogram of call of Pale-legged Leaf Warbler.

Pale-legged Leaf Warbler, call, Magic Parking Lot, 4 Sept. 2017 (00:01; 332 KB)

Audio spectrogram of call of Pale-legged Leaf Warbler.

Featured image: Pale-legged/Sakhalin Leaf Warbler, Yangkou, Rudong, Jiangsu, 1 May 2014. Photo by Craig Brelsford. Some of the salient characteristics of Pale-Sak are pointed out. Separating Pale-legged from Sakhalin on the basis of plumage and bare parts is not possible; because this bird was neither singing nor calling, it cannot be determined to which of the two species it belongs.

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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 eBirder in China, having noted more than 930 species, as well as the top-ranked eBirder in Shanghai (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 a master’s in business administration from the University of Liege in Belgium. Craig has lived in Shanghai since 2007.

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