Seen at Pudong’s Cape Nanhui on Sun. 4 June 2017: Kamchatka Leaf WarblerPhylloscopus examinandus. Veteran British birder Michael Grunwell and I found our 4 Kamchatkas in Microforest 4 (30.953225, 121.959083), the largest of the tree plantations on the landward side of the sea wall. The species is an all-time first for the Shanghai eBird list.
Just after sunrise, Michael and I, as is our wont, were doing “drive-by birding”–creeping along the edge of the road, listening out for birds. Suddenly, I heard an unfamiliar sound.
My gut said, “Hard, loud–Taiga Flycatcher?”
Taiga was not even close, of course. Note, however, what my gut was not saying: “Arctic Warbler,” a bird whose call I know well. This call was decidedly not an Arctic’s, though it soon dawned on us that we were hearing some type of leaf warbler.
To see why my gut did not say Arctic, compare my recordings of the tight “tzit” call of Arctic Warbler with the looser call of Kamchatka Leaf Warbler:
Kamchatka Leaf Warbler P. examinandus, Microforest 4 (30.953225, 121.959083), Cape Nanhui, 4 June 2017 (00:25; 4.9 MB)
Michael and I skidded to a stop and poked our heads into the green tangle of locust trees. The call was being followed by a song. Only upon hearing the song did I think of Arctic Warbler. But here too, the song, though similar, was distinctive–wavier than the straight trill of Arctic. Look at the spectrograms below.
After hearing several song-call cycles, Michael, my more experienced partner and the man who has taught me more than anyone about birding, first said the words “Kamchatka Leaf Warbler.”
Michael has birded the Indonesian islands of Flores and Komodo, where Kamchatka Leaf Warbler winters. Michael said that, last winter, walking through the forests there, he heard dozens of times the call of P. examinandus.
“I know that call,” Michael said.
I whipped out my Olympus DM-650 voice recorder and recorded the calling and singing warbler. Meanwhile, we caught our first glimpse of the individual. It was clearly an “Arctic-type” leaf warbler.
What is an “Arctic-type” leaf warbler? An Arctic-type leaf warbler is a member of one of four closely related taxa divided among three species: Japanese Leaf Warbler Phylloscopus xanthodryas, Kamchatka Leaf Warbler P. examinandus, and Arctic Warbler P. borealis borealis and P. b. kennicotti.
Arctic Warbler is by far the most widespread breeder in the complex. P. b. borealis breeds across northern Eurasia, from Scandinavia to northeast China and the Russian Far East. P. b. kennicotti breeds in western Alaska.
In 2010 Shanghai Birding member Per Alström et al. proposed the current way of viewing the Arctic-type warblers. Previously, the taxon examinandus was putative, not even reaching the subspecies level; Alström and his team showed that examinandus, with its distinctive song and call, merits recognition not as a subspecies of Arctic Warbler but as a species in its own right.
Of the three Arctic-type species, Japanese Leaf Warbler most stands out, being on average yellower than the two others. Arctic and Kamchatka look much more alike.
There are, however, some slight differences. Kamchatka is said to have a “marginally longer bill, tarsi and tail” than Arctic (del Hoyo & Collar). Sure enough, the Kamchatka I photographed is long-billed. Take a look below.
Michael and I heard our loudest song and calls during that first, early morning encounter. However, we heard Kamchatka calling throughout the day.
Our new Shanghai record, combined with late-May and early-June records from nearby Zhejiang, suggests that in this region, once the wave of Arctics passes through around 15 May, Kamchatka Leaf Warbler may be the Arctic-type to look out for.
Alström P., T. Saitoh, D. Williams, I. Nishiumi, Y. Shigeta, K. Ueda, M. Irestedt, M. Björklund & U. Olsson. 2011. The Arctic Warbler Phylloscopus borealis — three anciently separated cryptic species revealed. Ibis 153:395-410.
Brelsford, Craig, moderator. Shanghai Birding, a WeChat group. Discussions with various birders, chief among them Hangzhou birder Cheng Qian, who had information about sightings of P. examinandus in Zhejiang. Beijing-based Swedish birder Jan-Erik Nilsén also provided timely advice. To join Shanghai Birding, fill out the form on the shanghaibirding.com Sightings page. Please state that you wish to join Shanghai Birding. You may also friend Craig Brelsford (WeChat ID: craigbrelsford). In your friend request, please make it clear that you wish to join Shanghai Birding.
del Hoyo, J. & Collar, N. (2017). Kamchatka Leaf-warbler (Phylloscopus examinandus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona, Spain. (retrieved from http://www.hbw.com/node/1343935 on 6 June 2017).
Featured image: Kamchatka Leaf Warbler Phylloscopus examinandus. On 4 June 2017 at Cape Nanhui, birders Michael Grunwell and Craig Brelsford found the individual pictured here and three others. Photos by Craig Brelsford.
“I have thought a lot about yesterday and can honestly say, it must be one of my all-time ornithological highlights.”
— Dr. Mike May, message to Craig Brelsford, 14 May 2017
Those are the words not of a new birder, but of a highly experienced visiting birder with thousands of birds on his life list who resides in bird-rich Extremadura, Spain.
Birding Cape Nanhui at the height of the spring migration left Mike May open-mouthed. Should anyone be surprised? The southeastern-most point of Shanghai is a world-class birding site.
Mike’s 92-species day, Sat. 13 May 2017, with Beijing-based Swedish birder Jan-Erik Nilsén and me included ultra-rarities such as Orange-headed Thrush as well as Pallas’s Grasshopper Warbler and Lanceolated Warbler. A pair of sub-adult Black-faced Spoonbill were getting by on the ever-shrinking pools at the beleaguered site.
Let me say that again: Of the thousands of birding spots in this vast, mega-diverse nation, the cape 60 km southeast of People’s Square is second only to Baihualing in Yunnan in species noted.
Sound unbelievable? Let me say something even more unbelievable: Not only is this rich spot completely unprotected, with not even a square meter preserved in any legal way; but it is, to the contrary, being actively destroyed, even as I tap out these words.
The backdrop to the work of Mike, Jan-Erik, and me was fleets of bulldozers and backhoes, busy throughout the weekend. They clattered and clanged, and the pumps transferring water into the newly dug canals whirred and chugged.
The pace of transformation is faster than ever now.
“Nanhui is gone,” my partners and I said.
A major ecological area, a place combining ease of access to millions of residents of Earth’s largest city and a favorable position on Earth’s greatest migratory flyway, is being utterly transformed.
While the Cape Nanhui that I have long known falls, huge tracts of adjacent tidal mudflat are being reclaimed, adding dozens of square kilometers to the land area of Cape Nanhui. Birding there in theory could have a future. A Cape Nanhui Nature Reserve could be set up in the new area.
But even as the Cape Nanhui we know falls, no one, to my knowledge, has hastened to reassure conservationists that areas in the newly reclaimed land will be set aside for birds.
In the city-province of Shanghai, which is the size of the U.S. state of Delaware, a few places have indeed been set aside, among them Chongming Dongtan. But those reserves are small, on remote islands far from mainland Shanghai, and practically unreachable by the millions of middle-class Shanghainese who lack a car.
Cape Nanhui, by contrast, is easily reachable from the city. And it is the one place where masses of bird lovers can conveniently get a taste of the grand spectacle that is spring migration along the east coast of the Eurasian supercontinent.
That opportunity is being taken away, not only from the birders alive today, but also from the birders of the future.
THE THRILL OF NANHUI IN MAY
Our agony over the fate of Nanhui was tempered by the joy of birding. Orange-headed Thrush showed up Saturday at the Magic Parking Lot (30.884898, 121.968229). With the two vertical bars on its face, our specimen was either of race melli (breeds Guangdong, etc.) or courtoisi (Anhui).
On Sunday the Magic Parking Lot delivered singing Grey-crowned WarblerSeicercus tephrocephalus, and in Microforest 2 (30.926013, 121.970705) an appearance was made by Alström’s WarblerS. soror. Neither breeds in the region; both are very rare vagrants to Shanghai.
Iron Track (31.003613, 121.907883) gave us singing Yellow-breasted Bunting in full breeding finery and singing Pallas’s Grasshopper Warbler. I captured the latter’s song, rarely heard in Shanghai.
Pallas’s Grasshopper Warbler Locustella certhiola, 13 May 2017, Iron Track (31.003613, 121.907883) (00:13; 2.1 MB)
The Marshy Agricultural Land (30.850707, 121.863662) near Eiffel Tower was highly productive, yielding Lanceolated Warbler, Forest Wagtail, and Striated Heron.
Other highlights from Saturday along the 30-km stretch of coastline:
Shanghai Birding is the WeChat companion to this Web site. Our 126 members include everyone from persons brand-new to birding to some of the most knowledgeable birders in China. We discuss everything from the most common species to the most arcane.
You can join Shanghai Birding. Just friend me on WeChat (WeChat ID: craigbrelsford). Let me know that you want to join Shanghai Birding. I will add you.
Here is an edited transcript of a recent conversation on Shanghai Birding about the Seicercus warblers at Cape Nanhui:
Paul Holt: Can you post your recording of yesterday’s [14 May 2017] Alström’s Warbler as well please, Craig?
Craig Brelsford: Will post after I get home. Meanwhile, have you assessed the recording I posted yesterday morning? Do you agree it’s Grey-crowned Warbler? Jonathan Martinez, I’d like your view, too!
Craig Brelsford had earlier posted these sound recordings:
Grey-crowned Warbler Seicercus tephrocephalus 1/3, 14 May 2017, Magic Parking Lot (30.884898, 121.968229), Nanhui (00:36; 3 MB)
Grey-crowned Warbler 2/3 (00:49; 3.6 MB)
Grey-crowned Warbler 3/3 (01:08; 4.3 MB)
PH: Yes, Grey-crowned Warbler!
PH: For what it’s worth, while there are probably 30+ records of “golden-spectacled warblers” from coastal Hebei, very, very few have been as well documented as Craig’s and team’s recent Grey-crowned. Many have been photographed but far fewer sound-recorded. Alström’s is so far the only one so far known to breed north of the Qinling Shan (it’s a scarce and very local breeder at two, possibly three, sites in Beijing). Personally I’ve never seen soror in coastal Hebei (nor am I aware of any being sound-recorded there), but I have noted (and sound-recorded) 2 Bianchi’s S. valentini and 1 Martens’s S. omeiensis in coastal Hebei. I understand that the only (?) three coastal Hebei birds that have been captured and had their DNA compared have all been omeiensis. We’re very, very far from ascertaining the true statuses of these Seicercus in our area, but you perhaps should/might see more in Shanghai and coastal Zhejiang. As many of you already know, there are some excellent sound recordings of these on Per’s site.
CB: Great analysis, Paul, and great that you point out the resources on Per’s site. Jan-Erik and I got good sound recordings of the purported soror yesterday, and Charles Wu and I got some good shots, among them images of the outer tail feathers, which definitely had some white in them.
PH: Excellent, Craig. As you know they’ve all got white in their outer tails. Alström’s (aka Plain-tailed) doesn’t have much …
CB: Right, Paul; thanks. The discussion yesterday was one of comparison and degree. How little must the white be in the tail, we were asking ourselves, for a Seicercus to “qualify” as Alström’s/Plain-tailed? Was the white in our photos a little or a lot? We ended up thinking a little, and that and the song we recorded led us to a determination of soror. I’ll post my photos and recordings as soon as I’m home.
PH: Personally, Craig, I find it very difficult to judge the amount and distribution of white on the tails of these Seicercus in the field and think that a good photo with the tail splayed would really be necessary. Even then, the differences are small and subtle. Tricky group!
Jonathan Martinez: Regarding the ID of these Seicercus, I have found that call is by far the easiest way to ID them. They all have a characteristic call. Some of them, like Alström’s or Bianchi’s, are usually quite vocal; others not as much. It requires much more experience or use of sonogram to ID them by song, but a few of them (Alström’s especially) include their call in their song, and some of them (Grey-crowned, Martens’s) include a trill in their song. Others do not (Alström, Bianchi’s). ID-ing them on plumage is, of course, a level up.
Here is the voice of the Alström’s Warbler that I recorded with my Olympus DM-650 pocket recorder:
Editor’s note: The image above shows three cuckoos of the Shanghai region. Clockwise from L: Rufous Hawk-Cuckoo, Chestnut-winged Cuckoo, and Large Hawk-Cuckoo. Join us as we study the rich array of cuckoos that passes through Earth’s greatest city.
It is spring, and one of the most thrilling moments of the bird migration in Shanghai is upon us–the passage of the Cuculinae, the Old World brood-parasitic cuckoos. Nowhere in the world is the diversity of this group greater than in eastern Eurasia, and here in Shanghai we get an enviable selection. Let us examine our Shanghai-area parasitic cuckoos and learn how to tell them apart.
We can divide the Shanghai-area brood-parasitic cuckoos into two categories: the mainly grey, slender-bodied Cuculus cuckoos and the non-Cuculus cuckoos. We will look at the non-Cuculus cuckoos first.
MASTER MIMICS: THE HAWK-CUCKOOS
The non-Cuculus parasitic cuckoo that one is most likely to see in Shanghai is Large Hawk-CuckooHierococcyx sparverioides. In the microforests at Cape Nanhui and once, to my surprise, in inner-city Zhongshan Park, I have heard the scream of “Brain fever!” The species breeds in nearby Jiangsu and Zhejiang.
The hawk-cuckoos mimic sparrowhawks, an amazing feat of evolution. The resemblance serves, scientists say, not to increase stealth but to decrease it. Passerines, mistaking the intruder for a sparrowhawk, mob it, thereby giving away the location of their nest. After the tumult dies down, the hawk-cuckoo quietly swoops in and lays her egg.
When it comes to the business of eating, however, the masquerade ends. The hooked bill of a sparrowhawk is a butcher’s tool, made for stripping the flesh of vertebrates from bone. The bill of a hawk-cuckoo is blunt, the utensil of a caterpillar-eater. Need a quick differentiator between “sprock” and hawk-cuckoo? Look to the bill.
Another separation we Shanghai birders need to make is that between Large Hawk-Cuckoo and Rufous Hawk-CuckooHierococcyx hyperythrus. If seen clearly, adult Large Hawk-Cuckoo and Rufous Hawk-Cuckoo are readily separable. Rufous Hawk-Cuckoo shows a belly washed rufous with faint streaks. Large Hawk-Cuckoo is heavily barred and streaked and has the rufous coloring confined to the upper breast.
Adult Rufous Hawk-Cuckoo shows a white spot on the nape, white neck-sides, and white scapular crescents. These features may also be visible in sub-adult Rufous Hawk-Cuckoo. Large Hawk-Cuckoo shows none of these in any plumage.
Size differences may be appreciable. An average Large Hawk-Cuckoo is 15 percent larger than Rufous Hawk-Cuckoo. The tails differ, with the black subterminal band of Rufous Hawk-Cuckoo being bordered by a rufous line above and by the rufous tail-tip below. These rufous areas may be visible in immature cuckoos.
ASIAN KOEL AND CHESTNUT-WINGED CUCKOO
The other non-Cuculus parasitic cuckoos of the Shanghai region are Asian KoelEudynamys scolopaceus and Chestnut-winged CuckooClamator coromandus. Neither poses great ID challenges.
In China, Asian Koel ssp. chinensis breeds mainly south of the Yangtze River. With its familiar “koh-EL” song, Asian Koel is as easy to hear as it is hard to see in the dense forests where it is almost invariably found. It shows strong sexual dimorphism, with the male entirely glossy bluish-black and the female brown with whitish streaks, bars, and spots.
Five Cuculus cuckoos have been claimed for Shanghai: Lesser CuckooCuculus poliocephalus, Indian CuckooC. micropterus, Himalayan CuckooC. saturatus, Oriental CuckooC. optatus, and Common CuckooC. canorus.
The latter breeds in the area, parasitizing the nests of Oriental Reed Warbler in the reed beds at Cape Nanhui. Its famous song, perhaps the best-known bird sound in the world, is hard to miss at Nanhui in May.
Lesser Cuckoo and Indian Cuckoo breed in the region and are recorded on passage in Shanghai. Himalayan Cuckoo and Oriental Cuckoo may pass through Shanghai, but inasmuch as in size, plumage, and bare parts they are nearly identical to each other and very close to Common Cuckoo, and because they rarely (if ever) sing in our region, it is impossible to know how common they are.
Hear the song of any of these Cuculus, and you will have your ID; even the similar songs of Himalayan and Oriental are readily separable. If your cuckoo is silent, however, then you will need a closer look. Lesser Cuckoo and Indian Cuckoo have a brown iris, Common a bright-yellow iris. Lesser Cuckoo is the size of a thrush; Indian Cuckoo is a third larger; Common Cuckoo is larger still, approaching the size of a female Eurasian Sparrowhawk.
In autumn, juveniles pass through Shanghai. They are silent and nearly impossible to identify to species. If one gets a close look at juvenile Lesser Cuckoo, however, one may appreciate its thrush-like size. If you happen to be on the breeding grounds, then you can attempt an ID according to the species of the foster parent.
Lesser CoucalCentropus bengalensis is the good guy of the Shanghai cuckoo world. Unlike all the other cuckoos recorded in Shanghai, but like most of the cuckoos in the world, the coucals are not brood parasites. Lesser Coucal, resident in Shanghai, builds a dome nest on the ground.
Lesser Coucal may be the only non-Cuculinae cuckoo in Shanghai, but it shares at least one trait with the brood parasites: It is very unobtrusive. Look for Lesser Coucal in areas of thick vegetation near water, such as the strips of reed bed along the canals at Cape Nanhui. If you find one, count yourself lucky.
Greater CoucalCentropus sinensis occurs south of our region. It is nearly half again as large as Lesser Coucal and has a cleaner and glossier mantle, a thicker bill, and a redder iris.
RESOURCES ON CUCKOOS
The Sounds of Shanghai’s Cuckoos, by Craig Brelsford
All cuckoos from the Shanghai area are covered here. I make my recordings with my handy little Olympus DM-650.
In Shanghai, the best birding occurs on the coast, 80 km from the city center. Getting there can be a chore. Birding Pudong’s Century Park, by contrast, only requires a ride on Metro Line 2. Your day list from Century will only be about a third as long as a list from Cape Nanhui, but good birding can occur there, and at little cost.
On Sat. 15 April 2017, my partners Larry Chen, Komatsu Yasuhiko (“Hiko”), Hiko’s biology teacher Zeng Qiongyu, and I had a bout of good birding at Century Park.
I had never heard Eastern Crowned Warbler sing in Shanghai. I am however very familiar with the song, because in my wife Elaine Du’s hometown of Boli, Heilongjiang, the song of Eastern Crowned Warbler is one of the most common sounds in the remnant Manchurian forest. Elaine and I have birded Boli on three occasions, most recently in May-June 2016.
We were in the heavily wooded area near Gate 7 when I heard the wheezy song. It sounded just like this recording I made in Heilongjiang:
It was just a snatch of song, and it occurred but once. I knew immediately that it was Eastern Crowned Warbler. The song was coming from the surprisingly high canopy of the wood.
All four of us strained to find the bird. The sun shone brightly through the canopy and into our eyes. Finally, Hiko saw movement. Through the glare we focused in and got a clear view of Eastern Crowned.
It was a shot of birding as good and satisfying as I get anywhere. And it just goes to show–good birding can occur anywhere, even in a busy city park.
THANKS AGAIN TO KAI PFLUG
In this post I used several of Kai Pflug’s bird images. Kai and I have worked together from the earliest days of shanghaibirding.com, and I have published dozens of Kai’s photographs on this site. Kai’s work is regularly on view on our Sightings page, and Kai made a notable contribution to my October 2016 post “ID Workshop: Paradise Flycatchers.” In September 2016 I wrote about Kai’s work cleaning up the litter at Nanhui.
Kai is from Germany, lives in Shanghai, and is an active member of the Shanghai Birding WeChat group.
Thanks also to Shanghai Birding member Jonathan Martinez for his advice on Fork-tailed Drongo-Cuckoo and Plaintive Cuckoo.
Century Park (Shìjì Gōngyuán [世纪公园]; 31.219361, 121.551900), Pudong New Area (Pǔdōng Xīn Qū [浦东新区]), Shanghai, China. Includes records from Bird Island (31.217405, 121.554936). Mostly sunny; low 14° C, high 25° C. Visibility 10 km. Wind SSE 18 km/h. PM2.5 AQI: 112 (unhealthful). Sunrise 05:26, sunset 18:23. SAT 15 APR 2017 06:20-10:10. Craig Brelsford, Larry Chen, Komatsu Yasuhiko, & Zeng Qiongyu.
Little Grebe Tachybaptus ruficollis 7
Black-crowned Night Heron Nycticorax nycticorax 3
Common Moorhen Gallinula chloropus 4
Spotted Dove Streptopelia chinensis 12
Long-tailed Shrike Lanius schach 4
Azure-winged Magpie Cyanopica cyanus 35
Japanese Tit Parus minor 9
Light-vented Bulbul Pycnonotus sinensis 40
Pallas’s Leaf Warbler Phylloscopus proregulus 3 (2 singing)
Yellow-browed Warbler P. inornatus 1
Eastern Crowned Warbler P. coronatus 1 singing
Vinous-throated Parrotbill Sinosuthora webbiana 12
Japanese White-eye Zosterops japonicus 5
Chinese Hwamei Garrulax canorus 1
Red-billed Starling Spodiopsar sericeus 5
Chinese Blackbird Turdus mandarinus 50
Pale Thrush T. pallidus 4
Eurasian Tree Sparrow Passer montanus 10
White Wagtail Motacilla alba leucopsis 3
Olive-backed Pipit Anthus hodgsoni 16 (some singing)
Chinese Grosbeak Eophona migratoria 10
Tristram’s Bunting Emberiza tristrami 1
Black-faced Bunting E. spodocephala 6
Featured image: Clockwise from L, Rufous Hawk-Cuckoo Hierococcyx hyperythrus, Yangkou (Rudong), Jiangsu, October 2010; Chestnut-winged Cuckoo Clamator coromandus, Nanjing, Jiangsu, July 2009; and Large Hawk-Cuckoo Hierococcyx sparverioides, Nanhui, Shanghai, May 2016. All by Craig Brelsford.
Editor’s note: Dr. Nial Moores is director of Birds Korea and an authority on gulls. In this guest post, written especially for shanghaibirding.com, Moores describes the three widespread Herring-type gulls of East Asia. One of these is Taimyr Gull Larus (heuglini) taimyrensis. Moores points to the photos above to support the recognition, contested by some, of Taimyr Gull as a separate taxon. The panels show two Herring-type gulls, both adults, photographed on the Huangpu River in downtown Shanghai on 18 March 2017. The panels at left show Mongolian Gull Larus mongolicus. The right-hand panels show Taimyr Gull. The Mongolian is in full breeding plumage, as evidenced by its spotless white head. The Taimyr, by contrast, still shows streaking on its head, an indication that it has not yet attained full breeding plumage. The Taimyr shows as well upperparts darker grey than those of the Mongolian. These differences, Moores writes, show that the birds in question are two species.
Experts agree that Taimyr Gull is distinctive; what they disagree on is how to classify it. The IOC does not even recognize taimyrensis as a taxon, let alone a full species. Moores laments this state of affairs. The disagreements, Moores maintains, would melt away if more were known about these gulls. Moores wrote the post, and I am proudly publishing it, with a view toward fostering new knowledge. Birders, fear not the Herring-type gulls! Learn here from Moores, arm yourself with knowledge, and record and spread your observations. — Craig Brelsford
In his post “Loons Near Pudong Airport” (20 March 2017), Craig Brelsford posted an image of a Slaty-backed Gull and of a wing-tagged gull, referring to all the gulls in the background as Larus vegae vegae or Larus vegae mongolicus. In a public comment, I asked about Craig’s omission of Taimyr Gull Larus (heuglini) taimyrensis, leading to an exchange of e-mails between us and an invitation by Craig to post about this taxon. Below, therefore, are a few thoughts on Taimyr Gull, as depicted in Craig’s images taken 18 March 2017 on the Huangpu River in Shanghai, and a brief explanation of why many gullers no longer consider taimyrensis, vegae, and mongolicus to be the same species.
Visit a local river mouth, coastal wetland, or beach in winter, and the chances are high that you will see gulls. Some of the species found in East Asia, such as the Black-headed Gull Chroicocephalus ridibundus and Mew (or Common) Gull Larus canus, have a very wide geographic range and should be as familiar to domestic birders as they are to visiting birders from Europe and parts of North America. There are also a few gulls which are much more likely to stand out as different in structure and plumage. These include Relict Gull Ichthyaetus relictus and Saunders’s Gull Chroicocephalus saundersi. Both are highly distinctive East Asian “specials”; both are dependent on tidal flats in winter; both are globally Vulnerable; and both are confined entirely to this region and lack any counterpart elsewhere in the world (compelling evidence of the importance of the East Asian tidal flats to biodiversity).
And then there is a group that seems to fit neither of these categories: the so-called “Herring-type” gulls. There are three main Herring-type taxa found in this region, which the IOC Checklist effectively treats as one and the Birds Korea Checklist (Moores & Kim 2014) treats as three species: the Mongolian Gull Larus mongolicus, the Vega Gull Larus vegae and the Taimyr Gull Larus (heuglini) taimyrensis. All three of these gulls are widespread in this region in winter and can even be locally abundant. Importantly too, all three also have some kind of counterpart in other, better-researched regions. The Mongolian Gull in many ways looks most similar to the Caspian Gull Larus cachinnans of western Eurasia–most especially in that adults can look almost white-headed in mid-winter (at a time of year when more northern-breeding Herring-type gulls usually have densely spotted or streaked heads) and in their first-winter plumage. The Vega Gull looks more similar to the European Herring Gull Larus argentatus or the American Herring Gull Larus smithsonianus. As adults, all three have heavily streaked or mottled heads in non-breeding plumage, and all three are typically pink-legged at all ages (though with local exceptions–including in East Asia the paler-backed, yellow-legged individuals sometimes considered to be birulai, a subspecies of Vega Gull).
There are many similarities between Vega, European Herring, and American Herring Gulls in juvenile and immature plumages too, including, e.g., obvious notching on the tertials in the vast majority of juveniles and first-winters (first cycle), and in flight an obvious paler area on the inner primaries–often called a “window” by gullers–contrasting with a darker outer wing. The Taimyr Gull instead looks closest to the Lesser Black-backed Gull Larus fuscus of northern Europe in that adults are quite dark grey above and can have bright-yellow legs. The juvenile upper wing of both species also looks rather similar too, in that this pale area across the inner primaries is less obvious than in Vega or either of the Herring Gulls, while both Taimyr and Lesser Black-backed Gulls also have darker secondaries and a dark band across the greater coverts (though less striking in Taimyr than in Lesser Black-backed Gull).
NOTES ON TAIMYR GULL
In Craig’s image above from the Huangpu River in Shanghai, it is easy to see that at more or less the same angle, the upperpart grey of the adult to the rear is darker and a little slatier-looking than that of the wing-tagged gull in the foreground. A few other differences should be easy to pick out. One is the colour of the bare parts. The adult to the rear has extremely bright yellow legs and a vividly coloured bill, with the red on the gonys unusually bleeding up onto the upper mandible. The bird in the foreground, known by that wing tag to be from the breeding grounds of Mongolian Gull, has much weaker yellow-pink tones to the legs and the red confined to the lower mandible.
Leg colour can change seasonally, and bill markings change with age and apparently season too, but structure is more constant. The rear bird has a thicker-based bill and thicker-looking legs and also longer-looking wings, with at rest a rather more obvious extension of the primaries beyond the tail than shown by the Mongolian Gull in the foreground. There is another obvious difference: the streaking on the nape of the bird to the rear. Extent and density of head streaking is also a feature that changes seasonally and individually in gulls. What is important here is that on the same date, two apparently similarly aged gulls show several marked differences from each other, including that one of them still has a lot of streaking on the hind-nape and some grey wash near the eye; while the other, the Mongolian Gull, is already unstreaked and white-headed.
The combination of these differences (in structure, plumage tone, coloration of the bare parts, and head streaking) gives me confidence that these are adults of two species. And to be sure, while the adult Mongolian Gull in the foreground could perhaps be overlooked as a dark-looking American Herring Gull if seen in North America (where leg colour is more variable than in much of Europe: see here) or a big Caspian Gull if seen in Europe, an adult like the one just behind, with such yellow legs and such grey upperparts, would never be identified by any serious birder in Europe or North America as a Herring Gull. This bird would much more likely be identified as a Lesser Black-backed Gull instead–even if an odd-looking one. Notably, although the Lesser Black-backed Gull is largely restricted to breeding and wintering in Europe (with small numbers occurring in North America), the kind of gull in the image is quite common in East Asia. Here in Korea, I have seen several “pure” flocks of 40 to 50 birds looking just like this in March and April, and I counted a single flock of several hundred in Rudong a couple of Septembers ago. And often adults like these are accompanied by immatures of different ages–almost all of which after years of observation similarly fit neatly into an expected pattern of structure and plumage. Yes: The adult bird standing next to the Mongolian Gull is what an increasing number of birders now call Taimyr Gull.
The Taimyr Gull is a far northern-breeding species (confined, as far as we know, to breeding only on the Taimyr Peninsula: see van Dijk et al. 2011). Most adults do not attain full breeding plumage with gleaming white heads and bright bare parts until the middle or end of April. The most direct route from the Yellow Sea to their breeding grounds entails a flight of about 4,500 km (2,800 mi.) across land and environments which are hostile to gulls all the way. These gulls should not reach their breeding grounds too early, of course, either, because much of the Taimyr Peninsula will still be under snow and ice until the middle of May–a cold and deadly place for a gull until the summer thaw begins. Therefore, many adult Taimyr Gulls remain in the Yellow Sea until late April and early May, acquiring their full breeding plumage late before migrating rapidly, perhaps more or less non-stop, up to the northwest.
It is at least in part the huge distance that Taimyr Gulls need to fly over land between their breeding grounds and the rich fishing grounds of the Yellow Sea and south China coast that requires them to be so long-winged; and the brevity of the Arctic summer also determines when juveniles can start to moult into their next plumage and how much of their plumage they then need to moult. As in Lesser Black-backed Gull and Heuglin’s Gull Larus heuglini (the latter for now listed by the IOC as Larus fuscus heuglini, i.e., a subspecies of Lesser Black-backed), it appears that this moult is much more extensive in Taimyr Gull than in Vega, American Herring, or European Herring Gull.
Their first great transformation–from brown juvenile into a grey, white, and black first-winter–starts quite late, however. Most Taimyr Gulls, like Vega Gulls, are in juvenile plumage through December. Sometime in January or February of their second calendar year, Taimyr Gulls begin a rapid moult, with many by the end of February starting to look white-headed, and some showing patches of dark adult-type grey plumage in the scapulars and mantle by March and especially by April. For one or two months (from mid-February to mid-April), these young Taimyr Gulls can then start to look quite similar to young Mongolian Gulls, a few of which also seem to start to show some adult grey in their upperparts. The upper wing still looks different, though (especially the pattern on the inner primaries), and among the other differences visible on birds on the ground is that the base grey on the scapulars is quite dark; and the anchors and barring that overlie this grey area are much coarser than in Mongolian Gull. Most Taimyr Gulls have very coarse streaking on the nape, too. And all this new plumage, being so new, looks really fresh. They therefore do not have worn-out looking tertials like most Mongolians, especially locally bred birds. Of interest perhaps to those who enjoy studying gulls, in my 25 years in this region, and although both second-calendar-year Taimyr (regularly) and second-calendar-year Mongolian (sometimes) can show adult-type grey, I have not yet seen a single second-calendar-year Vega Gull in March or April with obvious adult grey in the plumage.
MONGOLIAN GULL, A MORE SOUTHERLY BREEDER
The Mongolian Gull (as far as we know) has a rather wider breeding distribution than Taimyr Gull and probably than Vega Gull. Mongolian is the species that breeds, or used to breed, north to Lake Khanka on the Sino-Russian border, northwest at least to Lake Baikal, and southeast to our region. This, after all, is the Herring-type gull that nests alongside Black-faced Spoonbills and Chinese Egrets on Yellow Sea islands in Korea and presumably very locally in China too. Breeding further south, their breeding grounds thaw earlier than those of the Taimyr Gull, which in turn means that Mongolian Gulls have to progress into breeding plumage much earlier than either Taimyr or Vega Gull.
By mid-February many adults are white-headed, and many are already prospecting nest sites. Here in Korea, by March many are paired up, giving their distinctive nasal braying courtship calls; birds can be sitting on eggs in April; and many of the young will have fledged by early June–this is before many Taimyr and Vega Gulls will have even started egg-laying! Mongolian Gulls (at least those born and raised in Korea) retain their dark brown juvenile plumage only until August or early September, before they start to moult rapidly into a quite pale-looking first-winter plumage. And by January, because this plumage is already several months old, young Mongolian Gulls already show a lot of wear, with extensive pale areas across the inner primaries contrasting with darker internal markings, which sometimes suggest black golf clubs.
Look carefully at the edges of the tertials, too: These often have uniquely frayed edges in mid-winter and early spring. These pale young Mongolian Gulls are the birds that look a lot like young Caspian Gulls, and are presumably much of the reason why Malling Olsen and Larsson (2004) treated Mongolian Gull as a subspecies of Caspian rather than lumping the taxon with Vega. They just look so different. In this region, we also get to see these young Mongolians accompanying adults on the tide-line and also often in freshwater habitats–along rivers and in lakes. This is an ecological niche they occupy which is largely avoided by both Taimyr and Vega Gulls. This is therefore the large gull of the Han River in Seoul and the Taedong in Pyongyang; and presumably of floodplain wetlands of the Yangtze River (and possibly of the Huangpu River in downtown Shanghai). As early as January, many of these young birds are already largely white-headed, with beautifully patterned scapulars (pale grey bases with dark rows of anchors), and often pale breasts and bellies: beautiful and strikingly different from either Taimyr or Vega Gulls at this time of year–both of which in January (as described above) are still mostly washed brown above and below, with heavily patterned heads and all-dark bills.
Structurally too, most Mongolian Gulls can be pretty obvious, being rather bulkier and more powerful-looking than Vega or Taimyr Gulls: a modest counterpart to the Great Black-backed Gull Larus marinus of the North Atlantic. And just like Great Black-backeds, Mongolians are often aggressive too. They sit in wait near to eagles on the Han River, and on multiple occasions I have seen them try to rob fish from Common Mergansers and harass groups of dabbling ducks. Here in Korea, they are often found patrolling rivers near flocks of roosting Baikal Teal, and at least a half-dozen times I have watched one swoop down to whack a hapless duck on the back of the head. I have seen this kind of aggressive behaviour only by birds that show multiple features of Mongolian Gull and never by birds showing multiple features of Vega or Taimyr Gull. And if you live and bird in eastern China, you have probably seen similar behaviour too, right?
VEGA GULL: NORTHEAST ASIAN BREEDER
The third of these Herring-type gulls is Vega Gull. From experience in Korea and southwestern Japan, I would be surprised if birders could find many Vega in a muddy river-mouth in Shanghai–especially on a date as late as mid-March. For at least on this side of the Yellow Sea, the Vega Gull is much more a species of fishing harbours, mariculture platforms, and sandy beaches. They do occasionally show up on rivers, but they are primarily a coastal species, strongly associated with, and perhaps now even dependent on, human fisheries when away from the breeding grounds. Much of their breeding range lies to the far northeast of Asia, not to the west or northwest. As a result, their migration and moult appear to be more staggered than that of Taimyr or Mongolian Gulls. After all, they have the option of remaining close to the coast and to fishing harbours along most of their migration route, with the potential to stop off en route to feed when they need to. This is presumably one reason why there are not so many Vega left in the Yellow Sea by mid-March. Many have already migrated out of the Yellow Sea and through the Korean Strait past Busan in early March, with much of the return migration back into the Yellow Sea in November (when thousands can be seen around fishing boats) and in December.
It is not only habitat and behaviour that helps in the identification of Vega Gull. Most adults are easy to pick out from Taimyr and Mongolian in mid-winter: sloping-backed and rather weaker looking than Mongolian; pink-legged and with pale yellow bill bases; dirty grey upperparts lacking slate tones; often heavily streaked and mottled on the head and down the breast sides. The ones easiest to ID also have a nice and distinctive primary pattern–showing a weak string of pearls and a more jagged edge of grey, black, and white than in Slaty-backed Gull. If you find a juvenile or immature gull in this region that looks pretty much like an American or European Herring Gull, then the chances are very high that it is a Vega.
Much is still to be learned, of course. But from what we can see in this region Taimyr, Mongolian, and Vega Gulls have their own preferred ecological niches; their own migration phenology and moult timing; and their own plumage characters and distinctive bare-part coloration. It also seems very likely that they have their own distinctive vocalisations, too. They also have distinct, separate breeding areas. And yet despite this, all three remain stuck in taxonomic controversy. The IOC does not list taimyrensis, for example, and UK-based BirdLife International (2017) recently even went the extra step and lumped Mongolian, Taimyr, Vega, and American Herring Gull into a single species, which they then named Arctic Herring Gull Larus smithsonianus (this seems worth repeating: a species that nests as far south as the Yellow Sea is now called Arctic Herring Gull by the world’s premier bird-conservation organisation).
A PAUCITY OF RESEARCH
The lack of understanding of these Asian gulls in Europe and North America is in large part owing to a paucity of research. Most of these gulls migrate huge distances between areas that are very hard to travel to for logistical and geopolitical reasons, and most of the research that has been done on them is not published in English or in peer-reviewed journals. Some of the problem also likely comes from gull experts based in Europe and North America then trying to make what little evidence they can access on these taxa to conform neatly to perceived counterpart European and North American species– taxa that are now pretty well-known after decades of study. This to me seems to be a major reason for the IOC’s inconsistency as well as BirdLife’s peculiar decision. By this I mean, this is why the IOC currently recognises the European Herring Gull, the American Herring Gull, and the Caspian Gull as three separate species, while not recognizing Taimyr Gull at all, and while also treating heuglini as a subspecies of Lesser Black-backed Gull and mongolicus as a subspecies of Vega. A more consistent approach might perhaps be instead to lump all Herring-types together; or to split all of the Herring-types apart when there is evidence to support it. All Birds Korea materials depend on the excellent recommendations of Gill and Donsker (2017) and the IOC Checklist–but not in the case of these gulls. To do so would require ignoring what appear to be consistent differences shown by these three taxa which are easily observable within this region.
Much still does need to be learned about these gulls, of course, whatever list you decide to follow and however you choose to organise your observations. Without doubt though, Mongolian, Vega, and Taimyr Gulls are a major part of the coastal birding experience in East Asia, and they offer great potential for pushing the frontiers of ID. It would therefore be very helpful for more birders to spend time on these and other gulls–looking for wing tags and bands, documenting moult progression with photographs, and generating ever-better information on this group of fascinating and under-appreciated birds.