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Nial Moores, Birds Korea, February 6, 2005.
 1st winter, Pohang © KIM Woo Soo
Relict Gull Larus relictus
 Breeding-plumaged Relict Gull, Gangneung, April 2002, © Choi Soon-Kyoo Distribution and Numbers The Relict Gull Larus relictus is a globally rare and little-known species, breeding in Mongolia, Kazakhstan, parts of China and southern Russia (Birdlife 2003), and suspected of wintering mainly in the northern part of the Yellow Sea (Moores & Moores, 2002). Its total world population has been estimated recently at between 2 500 and 10 000 individuals and declining (Birdlife International, 2003). It is therefore classified as Vulnerable, threatened by increasing disturbance in breeding areas and by massive reclamation of intertidal areas in the Yellow Sea. In South Korea, records of wintering birds range from between ca 6 and 185 individuals (with largest numbers coinciding with very cold winters, as in 2000/2001) and extreme dates falling between late November and early March, with stragglers into April. It is quite likely that fairly significant numbers are both underreported and still overlooked, especially as the species prefers the outer parts of tidal-flats and is not well-known by Korean birdwatchers.
 Relict Gull colony, Inner Mongolia, © Dr He Fen-qi Like many threatened species, the Relict Gull is highly specialized. Although it is a bird of saline lakes in summer (nesting on temporary islands), it is very much dependent on sandy and sand-mud tidal-flats in winter, being found therefore almost exclusively in the outer parts of estuaries or more rarely on sandy beaches. It appears to prefer shallow-sloping tidal-flat areas for feeding, roosting either on sea-ice, on small sandy islands or much more rarely on the sea when other roost sites are unavailable. Typical feeding action is very distinctive once known, allowing lone birds to be picked up at very long range. Relict Gull walk rather rapidly and a little pigeon-like, covering long stretches of tidal-flat, almost tiptoeing across the sandy tidal-flats as they pick at small shells. Typically they seldom interact with other species. Although claimed by Malling Olsen and Larsson (2003) to be wintering largely along the eastern coast of China into Viet Nam, there is very little supporting evidence for this. Rather, all the highest counts of the species have come from the northern part of the Yellow (or Bohai) Sea, either from "Happy Island" on the Hebei coast in autumn, or more recently from Tianjin Municipality, where there were 1,645 Relict Gull in March 2003 at the Tianjin Paleocoastal and Wetlands National Nature Reserve (Liu Yang et al, 2003), and 3,362 along a 6-km stretch of inter-tidal flats also in Tianjin municipality, on January 3rd, 2004 (Paul Holt in lit.), both areas with very extensive sand and sand-mud mix tidal flats. Considering this distribution it is not all surprising that the highest numbers of Relict Gull in South Korea are recorded in severe winters, presumably when seas and tidal-flats are frozen further north. Birds along the east coast (including most of those wintering at the Nakdong estuary) are presumably those moving south from the Russian Maritimes or perhaps the Tumen Delta and the eastern coast of the DPRK. Identification and Behavior
 Breeding-plumaged Relict Gull, Gangneung, April 2002, with Black-headed Gull Larus ridibindus (right). © Choi Soon-Kyoo. The Relict Gull is a reasonably easy species to identify if seen well due to its feeding behavior and structure, as well as its plumage and bare parts coloration. The species is found in four main age groups in Korea: First Winter (comprising the vast majority in mild winters); Second Winter; and Adult, either in non-breeding or breeding plumage (the latter from late February). The Relict Gull falls between Black-headed Larus ridibindus and Common GullLarus canus kamtschatschensis in size, but appears rather longer-necked, more pigeon-chested, and and perhaps proportionately shorter-legged with smallish feet, than either of these species.
  1st winter Relict Gulls: with Black-headed Gull upper right © Kim Woo-Soo (left); Song Do, January, © Charlie Moores/Birds Korea (right). First Winters are most easily confused with Common Gull. However, unlike Common Gull they look almost white-headed, with a band of heavy streaking on the nape, an almost clean rather pale grey “saddle” (much paler than typical “Eastern" Common Gull”) contrasting with dark-centred tertials and a variably brown wash on the coverts of the closed wing. Diagnostically, the legs and bill appear black or blackish, and the eye-ring thick and heavy, giving birds a rather sleepy and “primitive” look. Second Winters typically have reduced head and nape markings (often peppered with light grey flecks), show only weak dark markings in the tertials, and lack obvious white tips to the primaries of the closed wing.
Adult, moving from non-breeding into breeding plumage, Song Do, Incheon, February 2003. © Nial Moores/Birds Korea.Flying birds also have a distinctive shape, appearing rather “hump-backed” and small-headed. Wintering birds appear to be superbly adapted to extreme weather conditions. A flock of 143 at Song Do, Incheon, in the very severe winter of 2000/2001, roosted on sea ice during the high-tide, waited as other birds started to feed in dense flocks on the first exposed tidal-flats, and only when extensive areas of tidal-flat were exposed and other species more spread out, did they all start to walk out from the roost, slowly fanning out towards the sea edge, picking at shellfish and other tidal-flat animals.
 1st winter Relict Gull, Pohang. Photo © Kim Sung Hyun
Unpublished South Korean counts Known to Birds Korea
The following are a list of counts made since 2000 which are not yet listed by Birdlife International (2003) in their online account, but which will be forwarded on to it by Birds Korea (Pre-2000 counts, including a peak of 65 in January 1991 (at the Nakdong estuary) are detailed at www.rdb.or.id/view_html.php?id=123&op=larureli.
2000 2001 January 12th: 25, Nakdong estuary, Busan (Nial Moores and Kim Su-Kyung) January 14th: 14, Suncheon Bay, Jeollanam Province (Nial Moores, Kim Su-Kyung) January 20th: Two first winters, Posong Bay, Jeollanam Province (Nial Moores, Kim Su-Kyung) Late-January: One, Asan Bay, Gyeonggi Bay (Nial Moores, Kim Su-Kyung) February 3rd: Peak count of 143 (at least 83 adults), Song Do, Incheon (Nial and Charlie Moores) December 8th, Two, Song Do, Incheon (Nial Moores and Sunbird) December 29th, Three, Nakdong estuary, Busan (Nial Moores). 2002 January 7th, One second-winter, Nakdong estuary, Busan (Nial Moores, Kim Su-Kyung) January 10th, One, Suncheon Bay, Jeollanam Province (Nial Moores, Kim Su-Kyung) January 19th, One first-winter, Geum River estuary, Jeollabuk Province (Nial Moores, Kim Su-Kyung) January 29th, Three, Song-Do, Incheon (Nial Moores) February 6th: One First Winter and one Second Winter, Song Do, Incheon (Nial and Charlie Moores) April 14th: Breeding plumaged adult, Gangneung, Gangwon Province (Choi Soon-Kyoo) December 13th: 2 First winters, Pohang, Gyeongsanbuk Province (Andy Stoddart and Sunbird) December 25th: 2 adults and 1 first winter, Nakdong Estuary (Sean Minns) December 27th: 8, Nakdong estuary, Busan (Nial Moores) December 31st: 10, Nakdong estuary, Busan (Nial Moores and Tim Allison) 2003 January 10th: Three, Nakdong estuary, Busan (Nial Moores) February 12th: 2, Nakdong estuary, Busan (Nial Moores) February 14th: 14, Song Do, Incheon (13 adults), (Nial Moores and Bob Walton) February 15th: 14, Song Do, Incheon (10 adults, one Second Winter, 2 First Winters, one un-aged) (Nial Moores and Bob Walton) February 19th: Ten, Song Do, Incheon (Nial Moores, Gary and Marlene Babic) March 17th: One First Winter, Nakdong estuary, Busan (Nial Moores) April 27th: One First Winter, Geum estuary, Jeollabuk Province (Tim Allison) November 23rd: Three, Song Do, Incheon (Tim Edelsten) December 28th: Four, Nakdong estuary, Busan (Nial Moores, Barry Heinrich) December 28th: Two, Song Do, Incheon (Tim Edelsten) 2004 January 9th: Two, Nakdong estuary, Busan (Nial Moores and Tim Edelsten) January 13th: 3 (one adult, 2 First Winters) Nakdong estuary, Busan (Nial Moores, Peter and Erwin Collins) February 8th: 3, Song Do, Incheon (Tim Edelsten) February 24th: One First Winter, Nakdong estuary, Busan (Nial Moores) March 18th: One First Winter, Nakdong estuary, Busan (Nial Moores) March 28th: One First Winter, Gangwol Lake, Seosan, ChungCheongnam Province (Nial Moores, Ryan and Kara Lewantowicz) October 30th: One first winter, Dongjin estuary, Saemangeum (Nial Moores and Peter Mann). 2005 January 10th: Two, Nakdong estuary, Busan (Oliver Nieheus, Berit Ullrich) January 12: One First winter, Pohang, Gyeongsangbuk Province (Kim Sung-Hyun) January 22nd: One Second Winter, Song Do, Incheon (Nial Moores) January 23rd: One adult, Song Do, Incheon (Nial Moores, Gruff and Sara Dodd, Clive and Eleanor Hurley, Kingsley and Sharon Parker) January 25th: Seven or eight, Song Do, Incheon (Mochizuki Kenji)
References
Birdlife International (2003). Red Data Book Threatened Birds of Asia. Online version (at: www.rdb.or.id). |
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