Crested Goshawk Invades Shanghai

Crested Goshawk has sunk its talons into Shanghai. In the past year, records of the species have come from various locations throughout the city, in all four seasons. This past spring, a pair may have bred at Gongqing Forest Park.

It is remarkable that Crested Goshawk, a species of tropical and subtropical Asia, is even as far north as the Yangtze River. Most field guides show Accipiter trivirgatus indicus, the mainland form, occurring no farther north than Hangzhou. However, members of Shanghai Birding, the WeChat companion to this Web site, have reported Crested Goshawk in Nanjing and Nantong (Jiangsu). Other authorities record Crested Goshawk in Anhui, Henan, and even Beijing.

If the forest-loving goshawk has invaded the coastal, little-wooded, highly urbanized world of Shanghai, then it is not surprising that it would be using urban parks. Some of the parks of Shanghai, such as 102-year-old Zhongshan Park, where I found a pair of Crested Goshawk on 8 Sept., have massive trees and resemble old-growth forests.

Like the avifauna of islands, the birds of urban Shanghai’s green islands live in isolation. Except for stray cats and an occasional Siberian Weasel, urban residents Eurasian Tree Sparrow, Light-vented Bulbul, and Chinese Blackbird have few predators and are abundant.

With the imbalance comes an opportunity for raptors that can tolerate the noise and bustle of Earth’s Largest City. For Crested Goshawk, the pluses of urban living are apparently outweighing the minuses. It has come to feed on the rich store of passerines as well as mammals such as Pallas’s Squirrel.

On 16 May 2017 at Pudong’s Century Park, Shanghai Birding member Xueping Popp captured a Crested Goshawk exploiting the imbalance.

Crested Goshawk attacking Chinese Blackbird. Century Park, Shanghai, 17 May 2017. © 2017 by Stephan Popp & Xueping Popp
Crested Goshawk devouring Chinese Blackbird, Century Park, 17 May 2017. About this incident, photographer Xueping Popp wrote: ‘I went to Century Park early in the morning to look for Black Bittern. Nothing happened, so I decided to walk a little in the park. Suddenly I heard the cries of Chinese Blackbird. I looked up and saw a Crested Goshawk standing in the nest and eating a chick piece by piece. The scene was brutal, but Crested Goshawk was doing what raptors are supposed to do. I observed the whole process silently until the goshawk finished its meal.’ © 2017 by Stephan Popp & Xueping Popp.

Shanghai Birding member Wāng Jìn Róng (汪进荣) was one of the first birders to record Crested Goshawk in Shanghai. Jìn Róng has seen the species at Zhongshan Park and Gongqing Forest Park as well as on the grounds of the Shanghai Zoo. Jìn Róng took the photo at the top of this post as well as the photos immediately below. All were taken at Zhongshan Park–the photo above this past May, the photos below last December.

In December 2016 this Crested Goshawk made a very rare appearance in Zhongshan Park, Shanghai. Photo by Wāng Jìn Róng (汪进荣).
Crested Goshawk, Zhongshan Park, 18 Dec. 2016. Note the dark mesial stripe on white throat, heavy brownish to rufous streaking on the breast, and heavy rufous barring on the belly. The small nuchal crest is not seen here, being most obvious when the goshawk is in profile. (Wāng Jìn Róng).

The Crested Goshawk below, photographed by Shanghai Birding member Kai Pflug at Cape Nanhui, may have been in transit. Cape Nanhui has little tree cover beyond its famous microforests (where Kai got this photo), and Crested Goshawk is rarely recorded there.

Crested Goshawk, Cape Nanhui, April 2017. (Kai Pflug)
Crested Goshawk, Cape Nanhui, April 2017. Note large size but slim build and wings whose tips barely exceed the base of the tail. The short, rounded wings and long tail are adaptions to maneuvering through thick forest. (Kai Pflug)

Have you seen Crested Goshawk or other raptors in your city? Tell us your story in the comments below.

RESOURCES ON CRESTED GOSHAWK

Most field guides to Shanghai birds show outdated range maps for Accipiter trivirgatus indicus. Among them are Birds of East Asia (Brazil), A Field Guide to the Birds of China (MacKinnon & Phillipps), Handbook of the Birds of the World Vol. 2, and Raptors of the World (Ferguson-Lees & Christie).

The media below offer a clearer picture of the current status in China of Crested Goshawk.

Join Shanghai Birding for the very latest bird sightings in Shanghai.
Join Shanghai Birding for the very latest bird sightings in Shanghai.

Brelsford, Craig, moderator. Shanghai Birding, a WeChat group. The subject of Crested Goshawk generated discussions with various birders, among them Jiangsu birders Scoter and maidong, who had information about Crested Goshawk in Nanjing and Nantong. Hangzhou birder Cheng Qian reported on the distribution of Crested Goshawk in Zhejiang. Beijing-based member Paul Holt alerted us to scholarship on the changing distribution of Crested Goshawk and shared records of the species from Anhui and Beijing. Guangdong-based member Jonathan Martinez wrote about breeding Crested Goshawk in Hunan.

There are two ways to join Shanghai Birding. First, you need WeChat, the platform on which Shanghai Birding runs. Once you have installed WeChat, (1) fill out the form on our Sightings page or (2) friend Craig Brelsford on WeChat (ID: craigbrelsford). State that you wish to join the group.

eBird. 2017. eBird Range Map–Crested Goshawk. eBird: An online database of bird distribution and abundance [Web application]. eBird, Ithaca, New York. (Accessed: Sept. 14, 2017).

The eBird Range Map shows points on the Earth where checklists with Crested Goshawk have been submitted. The map shows Crested Goshawk in Zhejiang, Jiangsu, Anhui, and Henan as well as Shanghai.

Fei, Y.-L., Lei, M., Zhang, Y. and Lu, C.-H. Geographic Distribution Change of Crested Goshawk (Accipiter trivirgatus). Chinese Journal of Zoology 45 (2010): 174–175. Available here. (Accessed: Sept. 14, 2017).

Late Summer Shanghai

As summer melts into fall, Pudong’s Cape Nanhui continues to prove to be one of the best birding locations in China. In the period 26 Aug. to 8 Sept. 2017, I birded four days at the most southeasterly point of Shanghai, as well as at other key locations in Earth’s Greatest City. I noted 106 species.

Highlights were Brown-chested Jungle Flycatcher at Microforest 1, beautiful white-morph Amur Paradise Flycatcher at Binhai Forest Park, Fairy Pitta in the Cape Nanhui microforests, Greater Painted-snipe holding on in a canal near the coast, Asian Dowitcher at South Pond, Chinese Egret at North Pond and on South Beach, and Pacific Golden Plover at the sod farm south of Pudong Airport. Sakhalin Leaf Warbler and Pale-legged Leaf Warbler were calling in the Magic Parking Lot, and endangered Far Eastern Curlew and Great Knot were recorded at Nanhui. Crested Goshawk appeared in inner-city Zhongshan Park.

Here are some of the best birds:

Brown-chested Jungle Flycatcher
Cyornis brunneatus

Brown-chested Jungle Flycatcher, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
Brown-chested Jungle Flycatcher, Microforest 1 (30.923889, 121.971635), 4 Sept. 2017. Cyornis brunneatus is a very scarce vagrant to Shanghai. The species breeds in southeast China and spends the winter in Malaysia and Indonesia. (Craig Brelsford)

After nearly 10 years in Shanghai and countless visits to Cape Nanhui, I still occasionally score life birds there, a testament to the richness of the hot spot. Such was the case 4 Sept. with Brown-chested Jungle Flycatcher. The bird, an adult, was in Microforest 1 (30.923889, 121.971635).

Brown-chested Jungle Flycatcher is a very scarce vagrant to Shanghai. Cyornis brunneatus breeds in southeast China and spends the winter in peninsular Malaysia, Sumatra, and Borneo. It is uncommon even in its core range and virtually unknown in the Shanghai region outside Cape Nanhui; the place closest to Shanghai where I have heard of it occurring is Emeifeng, 635 km southwest of Shanghai in Fujian.

The IUCN lists the species as Vulnerable because of the loss of mature primary lowland forest throughout its range.

Brown-chested Jungle Flycatcher, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
I shoot in manual mode for fuller control. Here, using my seven-year old Nikon D3S and eight-year old Nikon 600 mm f/4, I chose the following settings: 1/160, f/11, ISO 1250. I used no tripod; instead, I steadied my rig on my knee. (Craig Brelsford)

Amur Paradise Flycatcher
Terpsiphone incei

Japanese Paradise Flycatcher
T. atrocaudata

Amur Paradise Flycatcher, Dongzhai, Henan, 2010. (Craig Brelsford)
Amur, Dongzhai, 2010. (C. Brelsford)

3 Amur found 27 Aug. at Binhai Forest Park, the heavily wooded green space near Cape Nanhui, 4.5 km inland from the East China Sea. A stunning white-morph male and rufous-morph were continuously together, and we found a single rufous-morph in another part of the park. The white-morph as well as the rufous-morph accompanying it were calling. I have seen dozens of paradise flycatchers in Shanghai over the years and heard only one call (a Japanese for 1 or 2 seconds). Why were the Amur at Binhai Forest Park calling?

Binhai Forest Park is visited little and birded even less; could this quiet, thickly wooded park hold breeding Amur Paradise Flycatcher? As the white-morph male looks like something out of a fairy tale and is a bird even a non-birder would recognize, I asked park employees whether they had seen it. All said no.

The white-morph Amur that U.S. birder Tom Hurley and I saw was only the second I had ever beheld and a first for me in Shanghai. At Dongzhai National Nature Reserve, Henan, on 5 June 2010, I photographed the white-morph shown right. The Binhai white-morph lacked the long tail feathers of the bird I saw at Dongzhai but was still an unforgettable sight.

Amur (top) and Japanese Paradise Flycatcher, Aug. 2017, Cape Nanhui. (Craig Brelsford)
Dorsal views of Amur (top) and Japanese Paradise Flycatcher. ​If the mantle, back, and tail have a purplish-brown hue, then you are likely looking at Japanese Paradise Flycatcher, known helpfully in Chinese as ‘Purple Paradise Flycatcher.’ If the upperparts are cinnamon-brown, then it is likely Amur. White-morph males are never Japanese, as the white morph does not occur in that species. 26-27 Aug. 2017, Cape Nanhui. For more on Amur-Japanese ID, see my post ‘ID Workshop: Paradise Flycatchers.’ (Craig Brelsford)

Japanese Paradise Flycatcher is the more common of the two paradise flycatchers in Shanghai. The photo above shows the differences in upperpart coloration between rufous-morph Amur Paradise Flycatcher and Japanese Paradise Flycatcher.

Fairy Pitta Pitta nympha

Fairy Pitta, Microforest 4, Cape Nanhui, Shanghai. 4 Sept. 2017. (Craig Brelsford)
Fairy Pitta, Microforest 4 (30.953225, 121.959083), Cape Nanhui, 4 Sept. 2017. The first week of September seems to be peak season for these passage migrants in Shanghai. The pitta shown here is a juvenile, discernible as such by the pinkish tip to its bill. The IUCN lists Fairy Pitta as Vulnerable. (Craig Brelsford)

On 4 Sept. at Nanhui, Elaine and I sneaked away from the action in Nanhui’s Microforest 1, where the photographers were set up. Microforest 4 was devoid of humans and peaceful. I tiptoed in. I scanned the undergrowth before me and, to my surprise, found a Fairy Pitta.

The pitta was standing on the ground, almost completely blanketed by a tangle of leaves, branches, and vines. Its big black eye was fixed on me. It didn’t move. I looked at the pitta, the pitta at me.

We stared at each other for 10 minutes.

Thus roosts the pitta during migration. It parks itself in thickets and waits. It bides its time, conserves its energy. Somewhere south of Shanghai, it will veer off the coast and fly non-stop across the South China Sea to Borneo, where it will spend the winter.

The pittas are mainly tropical species. Most are short-distance migrants. Not Fairy Pitta. No pitta invades the temperate world as deeply as Fairy Pitta; none makes so audacious an incursion into the north. None makes so long and daring a migration across hundreds of miles of sea.

My pitta was saving up its energy for its life-or-death run across the sea. Good luck, you explorer, you risk-taker! Good luck, Fairy Pitta.

Greater Painted-snipe
Rostratula benghalensis

Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
Nikon D3S, 600 mm f/4, 1/500, f/5.6, ISO 1000, hand-held (steadied on door of car). (Craig Brelsford)

Viewed with my wife Elaine Du at dusk 3 Sept. then viewed again the next morning at dawn. For weeks, the painted-snipes have been found at a single spot (30.939534, 121.955370) in a trash-strewn canal. Earlier, when news of the painted-snipe at Cape Nanhui first broke, I wrote a post in which I regretted sharing the location where were found the painted-snipes, a rare species in Shanghai. As things stand now, I can breathe easier; the many photographers who have visited the location have had no ill effect. The birds I found 4 Sept. were aware of me but behaved normally. They fed, drank, and preened. I used my car as a blind and never got out. The painted-snipes at Nanhui tolerate photographers confined to their cars.

Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
1/400, f/5.6, ISO 6400. (Craig Brelsford)
Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
1/250, f/10, ISO 1000. (Craig Brelsford)
Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
1/500, f/7.1, ISO 1000. (Craig Brelsford)
Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
1/400, f/5.6, ISO 6400. (Craig Brelsford)
Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
1/250, f/5.6, ISO 6400. (Craig Brelsford)
Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
1/320, f/10, ISO 1000. (Craig Brelsford)
Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
1/200, f/5.6, ISO 6400. (Craig Brelsford)
Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
1/200, f/5.6, ISO 6400. (Craig Brelsford)
Greater Painted-snipe Rostratula benghalensis, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
1/250, f/9, ISO 1000. (Craig Brelsford)

Asian Dowitcher
Limnodromus semipalmatus

27 Aug., South Pond. Juvenile. Videoed by me using my iPhone 6, adapter by the U.S. company PhoneSkope, and my Swarovski ATX-95 spotting scope:

Chinese Egret Egretta eulophotes

Below, video of Chinese Egret 26 Aug. at Cape Nanhui showing differences between Chinese Egret and Little Egret.

Other highlights:

Yellow Bittern Ixobrychus sinensis

Photographed by me in gorgeous morning light 4 Sept. at Cape Nanhui.

Yellow Bittern, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)
Yellow Bittern, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)

Black Bittern Ixobrychus flavicollis

Uncommon in Shanghai. Found 26 Aug. at Cape Nanhui.

Striated Heron Butorides striata

Uncommon in Shanghai. Found 27 Aug. at Binhai Forest Park.

Crested Goshawk Accipiter trivirgatus

Adult plus another goshawk calling unseen at inner-city Zhongshan Park on 8 Sept.

I videoed the goshawks:

Pacific Golden Plover Pluvialis fulva
Grey-headed Lapwing Vanellus cinereus

27 Aug. at sod farm south of Pudong Airport.

Great Knot Calidris tenuirostris

In high-tide roost 4 Sept. on South Beach (30.860673, 121.925113), just north of Donghai Bridge at Cape Nanhui.

Curlew Sandpiper C. ferruginea

South Pond, Cape Nanhui, 26 Aug. Video:

Pin-tailed Snipe Gallinago stenura

Pin-tailed Snipe, 3 Sept. 2017, Cape Nanhui. (Craig Brelsford)
Pin-tailed Snipe, 3 Sept. 2017, Cape Nanhui. (Craig Brelsford)

Party of 3 on 26 Aug. at Cape Nanhui. When flushed, made loud, raspy, memorable call. I quickly compared the call I had just heard to calls of Pin-tailed Snipe downloaded from xeno-canto.org to my iPhone. The match was perfect. Lookalike Swinhoe’s Snipe rarely calls when flushed. Dark underwing clear in my many photographs of the trio. Flew high when flushed, then returned to land at point only 50 m from where originally flushed.

Gull-billed Tern Gelochelidon nilotica

Gull-billed Tern, 4 Sept. 2017, Cape Nanhui, Pudong, Shanghai. (Craig Brelsford)
Gull-billed Tern, 4 Sept., Cape Nanhui. Note the thick bill. (Craig Brelsford)

The canals on the inland side of the sea wall were resounding with the characteristic yaps of this passage migrant. A clear photo is especially useful for discerning the thick bill.

Lesser Cuckoo Cuculus poliocephalus

Lesser Cuckoo, 26 Aug. 2017, Cape Nanhui, Shanghai. (Craig Brelsford)
Lesser Cuckoo, 26 Aug., Cape Nanhui. (Craig Brelsford)

Non-hepatic adult 26 Aug. at Cape Nanhui. See photo above. Reasoning behind ID of Lesser Cuckoo:

(1) No suggestion of brighter yellow iris that is characteristic of Eurasian Cuckoo as well as Oriental and Himalayan Cuckoo (darker iris more characteristic of Indian Cuckoo and Lesser Cuckoo)

(2) Dark rump and uppertail coverts contrast little with dark tail, while dark tail and rump contrast markedly with paler back, all pointing to Lesser Cuckoo

(3) On tail, very likely no subterminal black band (as in Indian Cuckoo), pointing again to Lesser Cuckoo

Cuculus sp., 4 Sept. 2017, Cape Nanhui. (Craig Brelsford)
This cuckoo, seen 4 Sept. 2017 at Cape Nanhui, has the dark eye, well-defined and widely spaced barring, and small size suggestive of Lesser Cuckoo. (Craig Brelsford)

Pale-legged Leaf Warbler
Phylloscopus tenellipes

Sakhalin Leaf Warbler

P. borealoides

In the wake of my post of 31 Aug. 2017 about distinguishing Pale-legged from Sakhalin Leaf Warbler by call, I was hoping to find more members of this species pair. On 4 Sept. 2017 at Pudong‘s Cape Nanhui, I was richly rewarded. For more, see my 10 Sept. 2017 post, “Pale-Sak Calls: An Addendum.”

Sand Martin Riparia riparia

Sand Martin, Cape Nanhui, 4 Sept. (Craig Brelsford)
Sand Martin, Cape Nanhui, 4 Sept. 2017. (Craig Brelsford)

Riparia riparia is an uncommon passage migrant in Shanghai. Note the well-defined breast band on my bird, distinguishing it from Pale Martin Riparia diluta, which has an ill-defined breast band.

Siberian Blue Robin Larvivora cyane

It’s worth stressing how good is our opportunity here in Shanghai to view Siberian Blue Robin for a few short weeks each spring and fall. On the breeding grounds up in northern China, the males sing loudly and beautifully but are very hard to see; no Siberian Blue Robin I experienced on the breeding grounds ever sang from anything like an exposed perch. The few I was able to see in Elaine’s hometown of Boli, Heilongjiang sang on or near the ground. Females are almost impossible to see; in fact, I saw not one in Heilongjiang in May-June 2016. Siberian Blue Robin are also apparently hard to see on their wintering grounds in south China and Southeast Asia. Places such as Cape Nanhui are probably among the best places in the world to view this common but shy species. We Shanghai birders have yet another reason to count ourselves lucky.

Also noted by me in Shanghai 27 Aug.-8 Sept. 2017:

Garganey Spatula querquedula
Common Pheasant Phasianus colchicus
Little Grebe Tachybaptus ruficollis
Grey Heron Ardea cinerea
Purple Heron A. purpurea
Great Egret A. alba
Intermediate Egret A. intermedia
Little Egret Egretta garzetta
Eastern Cattle Egret Bubulcus coromandus
Black-crowned Night Heron Nycticorax nycticorax
Chinese Pond Heron Ardeola bacchus
Common Moorhen Gallinula chloropus
Eurasian Coot Fulica atra
Black-winged Stilt Himantopus himantopus
Pied Avocet Recurvirostra avosetta
Kentish Plover Charadrius alexandrinus
Lesser Sand Plover C. mongolus
Greater Sand Plover C. leschenaultii
Little Ringed Plover C. dubius
Whimbrel Numenius phaeopus
Far Eastern Curlew N. madagascariensis
Eurasian Curlew N. arquata
Black-tailed Godwit Limosa limosa
Ruddy Turnstone Arenaria interpres
Red Knot Calidris canutus
Broad-billed Sandpiper C. falcinellus
Sharp-tailed Sandpiper C. acuminata
Long-toed Stint C. subminuta
Red-necked Stint C. ruficollis
Sanderling C. alba
Dunlin C. alpina
Common Snipe Gallinago gallinago
Red-necked Phalarope Phalaropus lobatus
Common Sandpiper Actitis hypoleucos
Grey-tailed Tattler Tringa brevipes
Spotted Redshank T. erythropus
Common Greenshank T. nebularia
Marsh Sandpiper T. stagnatilis
Wood Sandpiper T. glareola
Common Redshank T. totanus
Oriental Pratincole Glareola maldivarum
Black-tailed Gull Larus crassirostris
White-winged Tern Chlidonias leucopterus
Whiskered Tern C. hybrida
Common Tern Sterna hirundo
Feral Pigeon (Rock Dove) Columba livia
Red Turtle Dove Streptopelia tranquebarica
Spotted Dove S. chinensis
Himalayan Swiftlet Aerodramus brevirostris
Lesser Coucal Centropus bengalensis
Oriental Dollarbird Eurystomus orientalis
Eurasian Wryneck Jynx torquilla
Common Kingfisher Alcedo atthis
Common Kestrel Falco tinnunculus
Black-winged Cuckooshrike Coracina melaschistos
Tiger Shrike Lanius tigrinus
Brown Shrike L. cristatus
Long-tailed Shrike L. schach
Black-naped Oriole Oriolus chinensis
Japanese Tit Parus minor
Black-throated Bushtit Aegithalos concinnus
Japanese White-eye Zosterops japonicus
Barn Swallow Hirundo rustica
Light-vented Bulbul Pycnonotus sinensis
Arctic/Kamchatka Leaf/Japanese Leaf Warbler Phylloscopus borealis/examinandus/xanthodryas
Eastern Crowned Warbler P. coronatus
Oriental Reed Warbler Acrocephalus orientalis
Thick-billed Warbler Iduna aedon
Zitting Cisticola Cisticola juncidis
Plain Prinia Prinia inornata
Reed Parrotbill Paradoxornis heudei
Vinous-throated Parrotbill Sinosuthora webbiana
Javan Myna Acridotheres javanicus
Crested Myna A. cristatellus
Chinese Blackbird Turdus mandarinus
Grey-streaked Flycatcher Muscicapa griseisticta
Asian Brown Flycatcher M. dauurica
Oriental Magpie-Robin Copsychus saularis
Blue-and-white Flycatcher Cyanoptila cyanomelana
Yellow-rumped Flycatcher Ficedula zanthopygia
Chinese Grosbeak Eophona migratoria
Eurasian Tree Sparrow Passer montanus
Eastern Yellow Wagtail Motacilla tschutschensis tschutschensis
White Wagtail M. alba

Featured image: All-star birds of late summer 2017 at Pudong’s Cape Nanhui: Clockwise from top left, Brown-chested Jungle Flycatcher, Fairy Pitta, Greater Painted-snipe, and Great Knot. The Brown-chested Jungle Flycatcher and Greater Painted-snipe were photographed 4 Sept. 2017 at Cape Nanhui. Fairy Pitta photographed 5 June 2010 in Dongzhai, Henan, and Great Knot photographed 11 Sept. 2014 at Yangkou, Rudong, Jiangsu. All by 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.

Separating Pale-legged & Sakhalin Leaf Warbler on Call

Editor’s note: In the photo above, a Pale-legged Leaf Warbler emits its characteristic “tink” call in Microforest 4, Cape Nanhui, Pudong, 27 Aug. 2017. The tink call of Pale-legged is appreciably higher-pitched than that of Sakhalin Leaf Warbler. Distinguishing the two calls is the subject of this post. — Craig Brelsford

Last September, in “Pale-legged Leaf Warbler & the Shanghai Big 5,” I asserted that “Pale-legged Leaf Warbler is safely separable from Sakhalin Leaf Warbler only by song.” I was wrong. Call as well as song is a reliable separator. In this post, I am going to tell you how I arrived at this insight, and I will show you how you too can achieve clear, indisputable ticks of these tricky species through call alone.

Experts since at least as far back as 1989 have been arguing that Pale-legged Leaf Warbler Phylloscopus tenellipes and Sakhalin Leaf Warbler P. borealoides are separable not only by their distinctive songs but also by their calls. Thailand-based birder and shanghaibirding.com contributor Phil Round is among those making that argument. Round and his co-authors write: “[T]he call of P. tenellipes is markedly higher in frequency than that of P. borealoides” (Round et al., “Addition of Kamchatka Leaf Warbler Phylloscopus examinandus and Sakhalin Leaf Warbler P. borealoides to Thailand’s Avifauna,” downloadable through shanghaibirding.com).

If your ear is good, or even if your ear is just average and you have a sound-recorder, then you too can appreciate the higher frequency of the call of Pale-legged. A sound-recorder is very important, because if you upload your recordings to databases such as eBird and the Macaulay Library, then you will be able to “see” the sound in the audio spectrogram.

Our first exhibit is the spectrogram of a call I sound-recorded of Sakhalin Leaf Warbler on 8 May 2016 in Cape Nanhui’s Microforest 4 (30.953225, 121.959083). The frequency is 4.8 kilohertz, a number that matches closely the frequency of Sakhalin calls on xeno-canto.org.*

Audio spectrogram of call of Sakhalin Leaf Warbler.

Here is the sound-recording:

Sakhalin Leaf Warbler, call, Microforest 4 (30.953225, 121.959083), 8 May 2016 (00:15; 1 MB)

Now consider the spectrograms and sound-recordings of Pale-legged Leaf Warbler below. The spectrogram immediately below was recorded by me on 10 June 2016 in my wife Elaine Du’s hometown of Boli, Heilongjiang, part of the breeding range of Pale-legged Leaf Warbler. The call (here a grace note) and song both clock in at about 6 kHz, a frequency a full 25 percent higher than the call of Sakhalin Leaf Warbler and, as with Sakhalin, consistent with the frequencies of Pale-legged calls on xeno-canto.org.

Audio spectrogram of call plus song of Pale-legged Leaf Warbler.

Here is the sound-recording:

Pale-legged Leaf Warbler, call and song, Xidaquan National Forest (45.727751, 130.317316), Boli, Heilongjiang, 10 June 2016 (01:59; 6 MB)

The spectrogram below is of a brief sound-recording I made in Microforest 4 this past Sunday. The song element of this passage migrant is absent (though note that I have heard Pale-legged and Sakhalin singing in Shanghai in spring). The call has a frequency of 5.9 kHz and clearly belongs to Pale-legged Leaf Warbler.

Audio spectrogram of call of Pale-legged Leaf Warbler.

The sound-recording:

Pale-legged Leaf Warbler, call, Microforest 4 (30.953225, 121.959083), 27 Aug. 2017 (00:01; 193 KB)

Why should you care about all this? Because prepared birders have a chance to get solid ticks of “Pale-Saks” that are merely calling and not necessarily singing. If you hear a Pale-Sak calling and trust your ear (or better yet, sound-record the call and later analyze the spectrogram), then you may be able to go beyond the safe, boring record of “Pale-legged/Sakhalin Leaf Warbler” to a more satisfying full tick.

Pale-legged Leaf Warbler Phylloscopus tenellipes pumping its tail vigorously while remaining otherwise motionless and while standing (as is its wont) on a thick branch (top panels); and a second individual making its high-pitched "tink" call (bottom panels). Microforest 4 (30.953225, 121.959083, top panels) and Microforest 1 (30.923889, 121.971635, bottom panels), Cape Nanhui, Pudong, Shanghai, China, 27 Aug. 2017.
Pale-legged Leaf Warbler Phylloscopus tenellipes performing typical behaviors. Top panels: pumping tail vigorously while remaining otherwise motionless on a sturdy branch. Bottom panels: making the high-pitched ‘tink’ call, again on a thick branch. Microforest 4 (30.953225, 121.959083, top panels) and Microforest 1 (30.923889, 121.971635, bottom panels), Cape Nanhui, 27 Aug. 2017. (Craig Brelsford)

Accurate, plentiful records from Shanghai will help researchers such as Round get a clearer picture of the movements and population of these understudied species. As Round et al. write: “Increased sampling of migrants may also resolve the differences in timing of passage between P. examinandus and P. borealis on the one hand, and P. borealoides and P. tenellipes on the other” (“Addition”; hyperlink mine).

My trusty Olympus DM-650 sound recorder. In May, the height of migration season, my sound recorder is like the American Express card: 'Don't Leave Home Without It!'
My Olympus DM-650

What’s more, you do not need to spend much or even know much to record good audio. My Olympus DM-650 costs less than US$250. I have no microphone other than the one built into my pocket recorder, I possess no parabola, and I use no editing software. My editing is limited to snipping off the unusable beginnings and endings of my sound-recordings, which I record in lossless 48kHz .wav. The very scientific-looking spectrograms displayed in this post are generated automatically by eBird and Macaulay.

In Shanghai in 2017, important facts about common birds such as Pale-legged Leaf Warbler and Sakhalin Leaf Warbler remain unknown. This ornithological semi-wilderness is both difficult and exciting. If we rise to the challenge and become better birders, then we will make new discoveries and blaze a trail of knowledge for future birders to follow.

* Audio spectrograms are available for every sound-recording on xeno-canto.org. On the unique page created for each recording, find the section “Actions” and click “Download full-length sonogram.”