Relict Gull Ichthyaetus relictus Scientific name definitions

39–45 cm; 420–665 g. Size of L. melanocephalus and has similar summer head pattern, hooked bill tip and long legs, but differs in wingtip pattern and darker bill (1 Olsen, K. M., and H. Larsson (2003). Gulls of Europe, Asia and North America. Christopher Helm, London, UK. Close ). Breeding adult has hood black  , grading to pale brown between eye and bill; broad white eyelids  , often meeting behind eye; neck, underparts, rump and tail white; mantle, back and upperwing-coverts very pale grey; wingtip pattern distinctive , with outer 5–6 primaries largely white with pale grey base and black subterminal mark, outermost 2–3 having black outer web and p9 with broad black patch at tip; stout bill  dark red; legs red. Prior to 1970, was probably often misidentified for L. brunnicephalus, but is larger, with conspicuous eye-crescents and very different wingtip pattern. Primary pattern similar to that of L. ichthyaetus, but latter is considerably larger. Non-breeding adult loses dark hood, and has dark ear patch and streaking on crown and hindneck. Juvenile has scaly brown and white upperparts, with dark tail-band and black outer primaries; bill dark brown, legs dark grey. First-winter  has head white apart from dark brown mottling on crown and nape  ; upperwing-coverts extensively marked brown; black subterminal tail-band; dark bare parts. Second-winter plumage resembles adult winter but has more extensive black on wingtips. Second-summer shows only a trace of a hood and may have dark-centred tertials as well as a largely black wingtip with only small white primary tips. (1 Olsen, K. M., and H. Larsson (2003). Gulls of Europe, Asia and North America. Christopher Helm, London, UK. Close ).

E Kazakhstan (L Balkhash, L Alakol) (2 Rubinic, B. and Berezovikov, N.N. (2002). The fluctuation of breeding numbers of Relict Gull Larus relictus on Lake Alakol (SE Kazakhstan): a review of surveys from 1968 to 2001. Acrocephalus 23(115): 185–188. Close ), E Russia (L Barun-Torey, in S Transbaikalia), Mongolia, and China (where largest colonies thought to exist) in Inner Mongolia (Edsin Gol at Tsondol, Taolimiao–Alashan Nur, Maowusu Desert) and Shaanxi (Honjian Nur) (3 Duff, D.G., Bakewell, D.N. and Williams, M.D. (1991). The Relict Gull Larus relictus in China and elsewhere. Forktail 6: 43–65. Close , 4 He Fenqi, Zhang Yinsun, Wu Yong and Gao Tiejun (1992). The distribution of the Relict Gull Larus relictus in Maowusu Desert, Inner Mongolia, China. Forktail 7: 151–154. Close , 5 BirdLife International (2013). IUCN Red List for birds. URL: http://www.birdlife.org (download Aug 2013). Close ). Winter quarters still essentially unknown: some winter in S Korea; large numbers recorded at Bohai Bay (E China) (6 Heintzenberg, F. and Dierschke, J. (1996). Large numbers of Relict Gulls on Happy Island, China, in August–September 1994. Dutch Birding 18(2): 59–63. Close ), and there is evidence that some winter inland on the N Qinghai–Tibet plateau.

Breeds on shores or small islands of arid, usually saline, montane lakes , either on low-lying pebbly or clay rubble islands or spits; usually on islands at least 100 m from shore. Tends to avoid farms or fishing areas. Wintering birds are associated with coastal tidal mudflats (7 Yang, H.-Y., B. Chen, M. Barter, T. Piersma, C.-F. Zhou, F.-S. Li, and Z.-W. Zhang (2011). Impacts of tidal land reclamation in Bohai Bay, China: ongoing losses of critical Yellow Sea waterbird staging and wintering sites. Bird Conservation International 21(3):242–259. Close ).

Migratory. Young birds show post-breeding dispersal around their colony, before beginning migration in Sep. Part of population migrates through the E Gobi. Most birds appear to winter at coastal sites in E China. Small numbers also winter in South Korea. There are a few winter records of vagrants from Hong Kong, Vietnam and Japan (8 Collar, N. J., A. V. Andreev, S. Chan, M. J. Crosby, S. Subramanya, and J. A. Tobias, Editors (2001). Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK. Close , 9 Shimba, T. (2007). A Photographic Guide to the Birds of Japan and North-East Asia. Christopher Helm, London. Close ).

Feeds with quick, plover-like steps (1 Olsen, K. M., and H. Larsson (2003). Gulls of Europe, Asia and North America. Christopher Helm, London, UK. Close ). Known to take mainly insects, beetles, small fish and crustaceans; sometimes small birds and mammals (e.g. Microtus); occasionally eggs and young of birds. In Inner Mongolia feeds on insects and plant matter, with 90% of food items chironomid larvae. Forages in the surf zone of large lakes and in nearby grassy fields, within 5 km of colony. Wintering birds forage on mudflats.

Reportedly similar to L. melanocephalus. Breeding birds produce a short, trisyllabic “kaw kaw kaw” as well as hoarser notes; “arr”, “arrriu” and “rwiu”, like a barking dog (1 Olsen, K. M., and H. Larsson (2003). Gulls of Europe, Asia and North America. Christopher Helm, London, UK. Close ).

Highly gregarious. Returns to colonies early Apr to mid May; lays from early May. Mating reported to occur outside the colony, and also on nest. Frequently changes colony locations. Colonies  of 15–2000 pairs, often in discrete subcolonies. Generally beside Common Gull-billed Terns Gelochelidon nilotica and Caspian Terns Hydroprogne caspia; sometimes with L. cachinnans. Nest density is higher than in any other gull species, with a median inter-nest distance of 45 cm. Nest is a scrape surrounded by small stones, usually with small branches and grasses, and feathers. Clutch 2–3 eggs (mean 2·4–2·8); incubation 24–26 days; hatching from early Jun (Inner Mongolia); chick pale silvery grey, with fine dark grey spots on back and wings, pure white below; hatching weight 35–43 g; adults attack and often kill intruding chicks of other pairs; young tend to form crèche when alarmed. Chick mortality often high. First breeding at three years old.

VULNERABLE. CITES I. One of the scarcest of gulls but the discovery of more than 7000 nesting pairs in the Ordos Highlands of W Inner Mongolia and N China in 2010–2011 suggests that earlier assessments were underestimates. Global population thus now estimated at 10,000–20,000 mature individuals and up to 30,000 birds. Breeds at two localities in E Kazakhstan  (regularly at just one), one in Russia and several in Mongolia, whilst the largest colonies are thought to occur in China, at L Honjian Nur, Shaanxi (up to 5000 pairs) (8 Collar, N. J., A. V. Andreev, S. Chan, M. J. Crosby, S. Subramanya, and J. A. Tobias, Editors (2001). Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK. Close ). In China a colony of 434 nests was discovered at Gouchi wetland, Shaanxi Province, in 2013 (10 Xiao, H., Wang, K-F., Feng, N. and Xu, Z-Q. (2013). New Breeding Distribution of Relict Gulls in Gouchi Wetland, Dingbian , Shaanxi Province. Chinese Journal of Zoology. 48( 5) :776–777. Close ); in Mongolia, a colony of 383 nests at Ikhes Nuur, in the Gobi-Altai-Aimag, in 2012 (11 Buchheim, A., Kratzel, K., Langenberg, J., Langenberg, T., Schneider, A. and Tautz, S. (2015). Discovery of a Relict Gull Larus relictus breeding colony in Mongolia BirdingASIA. 24: 46–50. Close ). Non-breeding range incompletely known but large numbers recently found at Bohai Bay on coast of E China: 7880 near Tanggu, coastal Tianjin; and > 8000 in Nanpu-Caofedian area of coastal Tangshan, Hebei (7 Yang, H.-Y., B. Chen, M. Barter, T. Piersma, C.-F. Zhou, F.-S. Li, and Z.-W. Zhang (2011). Impacts of tidal land reclamation in Bohai Bay, China: ongoing losses of critical Yellow Sea waterbird staging and wintering sites. Bird Conservation International 21(3):242–259. Close ); up to 10,652 birds counted around Hangu, Tianjin, in Mar 2015 (12 Sykes, B. (2015). Boom or bust? Ten thousand Relict Gulls Larus relictus: record numbers seen at Hangu, Tianjin, China. BirdingASIA. 24: 51–53. Close ). At least six Chinese coastal sites held internationally important numbers during 2005–2013 (13 Bai, Q., J. Chen, Z. Chen, G. Dong, J. Dong, W. Dong, V. W. K. Fu, Y. Han, G. Lu, J. Li, Y. Liu, Z. Lin, D. Meng, J. Martinez, G. Ni, K. Shan, R. Sun, S. Tian, F. Wang, Z. Xu, Y. T. Yu, J. Yang, Z. Yang, L. Zhang, M. Zhang, and X. Zeng (2015). Identification of coastal wetlands of international importance for waterbirds: a review of China Coastal Waterbird Surveys 2005–2013. Avian Research 6(1):1–16. Close ). Small numbers also winter in South Korea, where most found on Nakdong estuary (8 Collar, N. J., A. V. Andreev, S. Chan, M. J. Crosby, S. Subramanya, and J. A. Tobias, Editors (2001). Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK. Close ).  Some apparently winter inland on N flank of Qinghai-Tibet plateau, China. Both breeding and wintering ranges are known to change markedly in response to weather conditions. Populations at some breeding sites, e.g. L Honjian, have increased, whilst others have declined dramatically. The breeding lakes are shallow and ephemeral, and potentially vulnerable to climate change. Colonies suffer high chick mortality due to adverse weather and predation; L. cachinnans may eliminate entire colonies. The species is reported to be extremely sensitive to disturbance in any form but some of the breeding lakes suffer from human disturbance for recreational and other purposes. The principal wintering locations are also under severe threat. In particular, Yellow Sea sites are threatened by the burgeoning human population, resulting in heavy pollution, unsustainable harvesting of shellfish and other natural resources, and the threat of reclamation of a large proportion of the remaining intertidal area (14 Barter, M. (2003). The Yellow Sea and its shorebirds. Bull Oriental Bird Club. 37: 35–42. Close , 7 Yang, H.-Y., B. Chen, M. Barter, T. Piersma, C.-F. Zhou, F.-S. Li, and Z.-W. Zhang (2011). Impacts of tidal land reclamation in Bohai Bay, China: ongoing losses of critical Yellow Sea waterbird staging and wintering sites. Bird Conservation International 21(3):242–259. Close ). Mudflat reclamation has also reduced the suitability of the Nakdong estuary, S Korea, for this species.