Each spring and autumn, two species of paradise flycatcher pass through Shanghai: Japanese Paradise Flycatcher Terpsiphone atrocaudata atrocaudata and Amur Paradise Flycatcher T. incei. The two species can seem confusingly similar, especially in the poor light of a wood. With a little practice you can tell the males apart, and with a lot of practice you should be able to separate the females. Here is what you need to know:
— If in Shanghai you see a white-morph paradise flycatcher, then by definition you are not looking at Japanese Paradise Flycatcher, and you are almost certainly looking at Amur Paradise Flycatcher.
No white morph exists in Japanese (Brazil). Regarding Amur, among my sources only Brazil expresses doubt about the existence of a white morph. shanghaibirding.com contributor John MacKinnon (A Field Guide to the Birds of China) and C.W. Moeliker (Handbook of the Birds of the World, Vol. 11) assure us that Amur white morph does exist. MacKinnon says that Amur white morph accounts for less than half of adult males.
We know that Amur white morph exists because we have seen it ourselves. On 30 May 2016, Kai Pflug photographed an Amur white morph at Cape Nanhui, the coastal birding site in Shanghai. In May 2010 at Dongzhai, Henan, 680 km (423 mi.) inland from Shanghai, I found an Amur white morph.
Could a white morph from a third species occur in Shanghai? Although the movements of paradise flycatchers are “complex and not fully understood” (Moeliker), I think we can presume that it is unlikely. The nearest third species is Oriental Paradise Flycatcher T. affinis saturatior, which according to MacKinnon winters no closer to Shanghai than Guangdong.
— The mantle, wings, rump, and tail of rufous-morph male Amur are rufous-brown; in Japanese, the mantle, wings, and rump are purplish-brown, and the tail is black.
The pictures speak for themselves. In good light you should have little trouble telling the two apart. The cinnamon tones of Amur are often what Shanghai birders notice first.
— Male Japanese has a black head and a black breast, forming a large hood. Amur rufous morph has black head and grey breast, forming a two-tone hood.
The hood of Amur has in addition more of a bluish tint than that of Japanese. Note the blue tint in the hood of Amur bottom left. Note also that the cobalt-blue eye ring of Japanese (top left) tends to be larger than the eye ring of Amur.
The females require more care to separate. Be persistent, get a good view, and try to get a photo. Note the following:
— Compared to Amur female, Japanese female has darker, duller, and less rufous mantle, wings, rump, and tail. Japanese has much darker (nearly all-black) flight feathers and sooty primary coverts.
For the bit about the sooty primary coverts, I am indebted to David Gandy of Bangkok City Birding.
— In their head and breast coloring, female Japanese and Amur show a pattern similar to that of the males. Whereas Japanese is more concolorous (panels 3 and 4), Amur shows more of a contrast between head and breast (1a, 1b, 2). Both Japanese and Amur female have whitish bellies, but the darker breast of Japanese contrasts more with the whitish belly than is the case with Amur. The head is glossier in Amur than in Japanese, whose crown is dull (inset, Panel 3). Japanese has faint rufous flanks, unlike Amur.
MAINLY SILENT IN SHANGHAI
In Shanghai, you will almost never hear a paradise flycatcher utter a sound. I have a single recording:
Japanese Paradise Flycatcher, call, Nanhui, May (00:01; 848 KB)
BACKGROUND ON THE SPECIES
Japanese Paradise Flycatcher Terpsiphone atrocaudata and Amur Paradise Flycatcher T. incei breed farther north than any other species in their mainly tropical genus. T. atrocaudata atrocaudata breeds in Korea, Japan, and Taiwan and is highly migratory, wintering as far south as Sumatra. (Birds in Taiwan, however, are largely resident.) T. incei, a monotypic species, is also highly migratory, with a breeding range extending into the Russian Far East and wintering grounds as far south as Java (Moeliker). Japanese is listed by the IUCN as Near Threatened, mainly because of habitat loss on its wintering grounds.
I have discovered two more photos of female Amur Paradise Flycatcher. The photos above were taken in July at Laoshan (32.071265, 118.560699), a site in Nanjing, Jiangsu 290 km inland from Shanghai. Note again in this Amur the contrast between bluish-black head and bluish-grey breast, the poorly defined border between the bluish-grey breast and the whitish belly, the lack of rufous coloration on the flanks, and the rufous-brown upperparts and tail, obviously brighter than in Japanese Paradise Flycatcher.
Brazil, Mark. Birds of East Asia. Princeton University Press. Studied entries on Asian Paradise Flycatcher and Japanese Paradise Flycatcher, p. 302.
del Hoyo, Josep, et al., eds. The Handbook of the Birds of the World. Lynx Edicions. Vol. 11, “Old World Flycatchers to Old World Warblers.” Species accounts for Asian Paradise Flycatcher (p. 289) and Japanese Paradise Flycatcher (p. 290) written by C.W. Moeliker.
MacKinnon, John & Karen Phillipps. A Field Guide to the Birds of China. Oxford University Press, pp. 284-5.
Robson, Craig. Birds of Southeast Asia. Princeton University Press. Helpful insights on Terpsiphone atrocaudata, T. incei, and T. affinis saturatior on p. 180.
Special thanks to Kai Pflug. Kai’s images of Amur Paradise Flycatcher are a valuable record of this poorly known species.
Featured image: The featured image above shows a stunning male Japanese Paradise Flycatcher and serves to introduce our theme: How can birders tell apart the two species of the remarkable genus Terpsiphone that migrate through Shanghai? (Craig Brelsford)
On the afternoon of 28 Sept. 2016, I saw in the drizzle an opportunity. In urban parks, light rain has little effect on the birds but a big effect on the humans. The parks are nearly empty. Elaine and I made the short walk from our apartment to Shanghai’s Zhongshan Park (31.221888, 121.420066). We had 15 species, 5 of them migrants: Yellow-browed Warbler 1, Arctic-type Warbler 2, Eastern Crowned Warbler 1, Grey-streaked Flycatcher 2, Dark-sided Flycatcher 2. To our Shanghai-area autumn 2016 list we added Black-throated Bushtit and Oriental Magpie-Robin.
When nearly empty, Zhongshan Park shows its natural side. The park is more than a century old, and some of the trees qualify as old-growth secondary. The many trees absorb the city’s sounds. The decibel level is low; one feels one has left the city. When a drizzle keeps the crowds out, this effect is magnified.
The illustration above shows Shanghai’s Big 5 Leaf Warblers: Pale-legged Leaf Warbler (1), Arctic Warbler (2), Eastern Crowned Warbler (3), Pallas’s Leaf Warbler (4), and Yellow-browed Warbler (5). In this post, I tell you how to separate Pale-legged and its lookalike Sakhalin Leaf Warbler from the others.
Recently at Cape Nanhui, the birding hotspot in Pudong, my object of observation was Pale-legged Leaf Warbler, one of the Big 5 Leaf Warblers in Shanghai. In both spring and autumn, Phylloscopus tenellipes passes through Earth’s greatest city in considerable numbers. A lookalike species, Sakhalin Leaf WarblerP. borealoides, also has been noted in Shanghai.
In this post, I shall outline the difficulty of distinguishing Pale-legged Leaf Warbler from Sakhalin Leaf Warbler on anything but call and song, and I will show you some of the traits of “Pale-Sak” that set this species pair apart from other leaf warblers.
SONG CAN SAFELY SEPARATE PALE-LEGGED FROM SAKHALIN
Pale-legged Leaf Warbler is safely separable from Sakhalin Leaf Warbler only by song and call. Every other trait of each can occur in the other. Numerous authorities confirm this. Swedish ornithologist Per Alström calls the two species “almost identical” and “virtually indistinguishable except by song” (Alström 2012). Mark Brazil says field separation of Pale-Sak is “uncertain,” and he warns readers to “beware light conditions” (2009). Clement writes that Pale-legged and Sakhalin are “very similar” and claims, dubiously, that the latter is distinguishable from the former “mainly by greener upperparts and lack of wingbars” (2006). Clements goes on to describe juvenile Pale-legged as being “more greenish on upperparts,” which begs the question of whether the greenish Pale-Sak one is observing is an adult Sakhalin or a juvenile Pale-legged. Moreover, a quick look at Oriental Bird Images shows many Sakhalin Leaf Warbler with wing bars.
Thankfully for us birders, the songs of the two species are distinctive and provide the basis for a safe ID. The song of Pale-legged, occasionally heard in Shanghai in May, is a cricket-like trill, that of Sakhalin a high-pitched, three-note whistle.
One day in May, I heard Pale-legged and Sakhalin singing together in Zhongshan Park—proof that Sakhalin passes through Shanghai. Usually, however, birders here are forced to perform the less than satisfying task of assigning the individuals they see to the category “Pale-legged/Sakhalin Leaf Warbler.”
Bottom line: In Shanghai, any Pale-Sak one sees is probably Pale-legged Leaf Warbler, the continental breeder, and not Sakhalin Leaf Warbler, the breeder from the eponymous Russian island plus Hokkaido and Honshu; but to claim certainty about any non-singing individual is the taxonomical version of Russian roulette.
DISTINGUISHING PALE-SAK FROM OTHER LEAF WARBLERS
The Pale-Sak species pair is readily distinguishable from other leaf warblers, in particular the other four members of Shanghai’s Big 5: Pallas’s Leaf WarblerPhylloscopus proregulus, Yellow-browed WarblerP. inornatus, Arctic WarblerP. borealis, and Eastern Crowned WarblerP. coronatus.
Here are a few principles:
— Pale-legged Leaf Warbler and Sakhalin Leaf Warbler are plain, mid-sized to large leaf warblers without even the hint of a coronal stripe.
— Pale-legged/Sakhalin Leaf Warbler has distinctive pink legs and a short bill with a black smudge on the lower mandible, which is pink at the base and tip.
Even on a fast-moving Pale-Sak in poor light, the pink of the bill and especially of the legs is readily seen. The distinctive pale color of these bare parts is a handy tool for distinguishing Pale-Sak from birds in the Arctic Warbler Complex, which like Pale-Sak lack a crown stripe and usually show one or two wing bars. (The Arctic Warbler Complex consists of Arctic WarblerPhylloscopus borealis, Kamchatka Leaf WarblerP. examinandus, and Japanese Leaf WarblerP. xanthodryas. In Shanghai, Arctic Warbler is the most common of the three, migrating through Shanghai every spring and autumn.) The pink coloration also distinguishes Pale-Sak from Dusky WarblerP. fuscatus, an uncommon migrant and winter visitor in Shanghai, and the scarce passage migrant Two-barred WarblerP. plumbeitarsus.
— Pale-legged/Sakhalin Leaf Warbler constantly pumps its tail.
The tail-pumping of Pale-legged/Sakhalin is one of the most distinctive behavioral traits of the species pair. The steady movement usually occurs independently of other muscular actions and is slow enough for the eye to see. The tail-flicking of Arctic Warbler, by contrast, is more spasmodic and is often accompanied by wing-flicking.
— Pale-legged/Sakhalin Leaf Warbler is often found on the lower, thicker branches of trees.
With its ability to forage along thick branches and not just glean from the underside of leaves, Pale-legged/Sakhalin can remind one of a nuthatch. Other species such as Arctic Warbler use the lower branches, but sustained observation shows Pale-Sak more often in those areas. Note: In May and June 2016, I studied Pale-legged Leaf Warbler on its breeding grounds in Heilongjiang. There, amid trees older and taller than one usually sees in Shanghai, I most often noted the species far above my head, in the mid-canopy.
A NOTE ON CALLS
Except for the mainly silent migrant Eastern Crowned Warbler, Shanghai’s Big 5 Leaf Warblers all call in both spring and autumn. The calls are distinctive. The metallic “tink” of Pale-Sak contrasts markedly with the “tzit” of Arctic Warbler, the “dweet” of Pallas’s Leaf Warbler, and the “sweet” of Yellow-browed Warbler.
Sakhalin Leaf Warbler, Cape Nanhui, Shanghai, May (00:15; 1.4 MB)
Arctic Warbler, Jiangsu, May (00:09; 1.9 MB)
Pallas’s Leaf Warbler, Jiangsu, May (00:05; 1.6 MB)
Editor’s note: This post caught the attention of Philip D. Round, a professor at Mahidol University in Bangkok and an expert on leaf warblers. In an e-mail to me, Round writes that as discoveries are made and papers published, separating Pale-legged Leaf Warbler from Sakhalin Leaf Warbler on call may become more widespread. Separation on morphology, by contrast, will be much more difficult, though it may eventually turn out to be possible in the hand.
The following paragraphs are from Round’s e-mail to me:
“I enclose a paper that details the first records of both Kamchatka Leaf Warbler and Sakhalin Leaf Warbler from Thailand. [Editor’s note: the paper, “Addition of Kamchatka Leaf Warbler Phylloscopus examinandus and Sakhalin Leaf Warbler P. borealoides to Thailand’s Avifauna,” is available for download through shanghaibirding.com (708 KB).] This has been rather overtaken by events, as we have now caught into the hundreds of Sakhalin LW, mostly on spring passage, and quite a few more Kamchatka. I have an undergraduate student who has carried out DNA assay on about ten percent of all the Pale-legged and Sakhalin LW caught. For many of these we have also recorded call notes on release. When she comes back from overseas study in January 2017 I hope we’ll get a paper out which publishes details of call-note frequency and DNA results for this large sample, which should show the correlation between species and call-note frequency clearly. (Actually this is moderately and anecdotally well-known already. I think either Frank Lambert or Jonathan Martinez was the first to draw my attention to the difference, and it is mentioned by Yap et al. in BirdingASIA with reference to an overwintering Singapore bird.) [Note: Round is referring to Yap, Francis et al., “First wintering record of the Sakhalin Leaf Warbler Phylloscopus borealoides in South-East Asia, with notes on vocalisations,” BirdingASIA 21 (2014): 76–81.]
“I am a bit less sanguine on finding means (other than by call frequency or song) to separate all birds. Even in the hand, it is by no means clear. We can pick out long-winged male Sakhalin, and short-winged female Pale-legged. But there is more overlap than previously realized, and most are in between. There don’t appear to be any 100% consistent wing-formula differences, and plumage and bare-part features, while somewhat indicative, are again less than 100% reliable—especially under field conditions. But probably we are missing something. The next thing to do is to apply PCA or some other multivariate analysis to figure out reliable means of separation of birds in the hand from our large sample, and also to use the information we have to figure out differences in the timing of passage of the two spp.”
Alström, P. (2012). Identification of Phylloscopus & Seicercus Warblers in China. Notes from presentation given to Beijing Birdwatching Society in November 2012. PDF downloadable here (13 MB). Click here for a 5 MB zip archive containing all 40 pages of the report in JPEG form. Those pages can be synced to your smartphone like photographs and consulted in the field. (Accessed: 27 Jan 2020)
Brazil, M. (2009). Birds of East Asia. Princeton, New Jersey: Princeton University Press.
Clement, P. (2006). Family Sylviidae (Old World Warblers). Pp. 663-4 (Pale-legged Leaf Warbler, Sakhalin Leaf Warbler) in del Hoyo, J., Elliott, A. & Christie, D.A. eds. (2006). Handbook of the Birds of the World. Vol. 11. Old World Flycatchers to Old World Warblers. Lynx Edicions, Barcelona, Spain.
Featured image: Shanghai’s Big 5 leaf warblers. (Craig Brelsford)
Stimulating discussions about leaf warblers enlivened the lulls on Sat. 24 Sept. 2016, a day in which my wife Elaine Du and I once again partnered with veteran British birder Michael Grunwell. We noted 69 species, starting at the sod farm south of Pudong airport then spending the rest of the day at Cape Nanhui. Highlights:
Juvenile spotted on mudflats at high tide. A far-northern, trans-Eurasian breeder, Philomachus pugnax is a scarce passage migrant in Shanghai. Amid the greenshanks and godwits, the Ruff stood out with its buff-washed head and scaly upperparts. Juvenile Ruff resembles Buff-breasted Sandpiper, a much smaller American bird that we quickly ruled out.
A week ago ca. 2500, on Saturday only 10. Coastal birding is a parade of change, especially in migration season.
Other goodies: Eurasian Wryneck 2, Japanese Paradise Flycatcher 6, Amur Paradise Flycatcher 1, Richard’s Pipit 5, White’s Thrush 5 first-of-season, Rufous-tailed Robin 1 first-of-season. We introduced Benjamin to Reed Parrotbill calling unseen from the reeds below, we had a strong count of 16 Blue-and-white Flycatcher, and we noted two endangered species: Far Eastern Curlew and Yellow-breasted Bunting.
Distinguishing non-breeding Nordmann’s Greenshank from Common Greenshank is a tricky task, but one that reaps rewards. With practice you too can feel the rush that comes when you realize that the greenshank you are viewing is not one of the most common shorebirds in Eurasia, but one of the rarest. At Cape Nanhui in Pudong, our team experienced that thrill, picking out a Nordmann’s in a roost holding a few hundred shorebirds.
We noted the following:
— Tibiae of Nordmann’s Greenshank are noticeably shorter than those of Common Greenshank.
The picture above makes it clear. The biggest reason Nordmann’s is known as the stockier bird, the rugby player compared to the ballerina that is Common Greenshank, is tibia and leg length.
— Nordmann’s has a thicker neck that it often holds closer to its body and has a pronounced ventral angle (protruding belly), giving Nordmann’s a more hunched appearance than Common.
As with many of the characters of these species, the hunched stance of Nordmann’s is not always obvious, especially when the bird is active. Likewise, even a Common sometimes can appear stout. But as one’s observation time grows, the classic features of both species will emerge.
— Nordmann’s has a thicker, more obviously bi-colored bill than Common.
Because the Nordmann’s at our Nanhui roost did not fly, we missed the following key characteristics:
— The toes of Nordmann’s project just beyond the tail-tip; the toes of Common project farther.
This difference can be subtle, and a good camera is sometimes needed to appreciate it. But it is consistent.
— Nordmann’s has a cleaner tail and underwing than Common.
Even if your Nordmann’s is roosting, you can sometimes note the white underwing. Wait for the bird to stretch out its wing.
— The calls of Nordmann’s Greenshank and Common Greenshank are markedly different. The well-known “chew-chew-chew” call of Common is never made by Nordmann’s.
— In breeding plumage the species are more readily distinguishable. Nordmann’s Greenshank is also known as Spotted Greenshank for good reason. The heavily spotted underparts of breeding Nordmann’s are diagnostic. Unfortunately for birders in Shanghai, however, Nordmann’s in full breeding plumage is rarely seen.
Nordmann’s Greenshank Tringa guttifer is an endangered species. Only 500 to 1,000 of these birds are thought to remain. Development along the East Asian coast is the main reason for its decline. Nordmann’s breeds in Russia, passes through China, and winters in Southeast Asia. It is present in the Shanghai area for several months each year.
Featured image: Nordmann’s Greenshank stands among wader roost at Cape Nanhui, Shanghai. Using the principles described in this post, our team was able to ID this Nordmann’s. (Komatsu Yasuhiko/Craig Brelsford)