email a friend
printable version
VU
Saunders's Gull Larus saundersi

Justification
This species's moderately small population is thought to be in decline, and this is likely to become rapid over the next three generations (18 years) as a result of land reclamation on tidal flats and disturbance at colonies, resulting in its listing as Vulnerable.

Taxonomic source(s)
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Identification
33 cm. Diminutive gull with shortish, black bill. Breeding adults have black hood extending to nape and broad, broken white eye-ring. Non-breeders have white tips and small, black subterminal markings on outer primaries, small black tips to inner primaries, narrow, broken, dark secondary band and narrow black tail-band. Similar spp. Black-headed Gull L. ridibundus is larger, less compact with longer bill and white leading edge to wing.

Distribution and population
Larus saundersi breeds in eastern mainland China, and sporadically at sites on the south-west coast of South Korea (BirdLife International 2001). The most important breeding grounds are Yancheng National Nature Reserve and Shuangtai Hekou National Nature Reserve in China. A count of 1,317 birds was made at Shuangtai Hekou, Liaoning in October 2001 (Robson 2002), with 8,671 adults recorded and 399 banded in 2007 (Jiang Hongxing 2007). At the Yellow River Delta of Shandong, 801 adults were recorded and 27 juveniles banded, while in Yancheng of Jiangsu, 575 adults were recorded in 2007 (Jiang 2007). Non-breeding birds occur in North Korea, where it may also breed. It winters in eastern and southern China (9,625 individuals), from Jiangsu southwards, Hong Kong (China) (35 individuals), Macau (China), Taiwan (China) (700 individuals), along the western and southern coast of South Korea (2,000 individuals), in south-western Japan (2,000 individuals) and in Vietnam (10 individuals) (Cao et al. 2008). The coast of Dandong is an important stopover site on the flyway of Panjing-Japan, with 232 adults sighted in April 2008, 75% of which were sub-adults in their first winter (Bai Quing-Quan 2008). The key wintering grounds are Bohai Bay, where 864 birds were counted in 2005/2006 (Liu Yang et al. 2007) and Wenzhou-Yueqing bays, Guangdong and Guangxi in China and Suncheon-Kwangyang bays, with c.750 individuals recorded at Kum River estuary in January 2004 (Kim Hark-Jin in litt. 2004), in South Korea. The global population is estimated to be 7,100-9,600 birds although recent figures point to a minimum of 14,400 birds, mostly likely due to increased survey effort rather than any real increase in the population (Cao et al. 2008). However, it is likely that the population is continuing to decline, given the significant threats to habitat and high human disturbance levels occurring across the species's range (Jiang et al. 2010).

Population justification
A population estimate of 14,400 mature individuals has been derived from analysis of records and surveys by BirdLife International (2011). This is roughly equivalent to 21,000-22,000 individuals in total.

Trend justification
The species's population is presumed to be declining in line with the rate of habitat loss owing to land reclamation, which is anticipated to increase in the near future. Studies at specific sites have shown declines, for example a drop from over 900 individuals to 575 in the last 15 years at Yancheng National Nature Reserve (Jiang et al. 2010).


Ecology
It nests on the ground and is restricted to common seepweed Suaeda glauca saltmarsh habitats. Wintering birds are found on estuarine tidal flats with regular movements between different sites dependent on weather and food supply.

Threats
The key threat is reclamation of tidal flats and saltmarshes, particularly in China, Taiwan, South Korea and Japan. From 1990-1995, many former breeding sites at Yancheng were lost through reclamation and construction. Common seepweed habitat, in which the species nests, decreased in areas by 79.1% (27,358 ha) over 15 years predominantly as a result of conversion to aquaculture ponds (Jiang et al. 2010). In 2011, many chicks and eggs at a breeding colony in Panjin were lost to rising water levels associated with land conversion to aquaculture ponds, which is a potential future threat to other colonies (Liu Yang in litt. 2012). The introduction of smooth cordgrass Spartina alterniflora in 1982 has also caused considerable habitat degradation by replacing common seepweed habitats and increasing in area by 322% (11,057 ha) between 1999 and 2007 (Jiang et al. 2010). The other two breeding sites in China, Shuangtai Hekou and the Yellow River delta, are major oilfields and birds are under increasing threats from pollution and human activities. Reclamation developments associated with the Tianjin New Coastal District project (started in 2006) had seriously impacted an important wintering area by autumn 2011, resulting in a substantial loss of inter-tidal mudflats in Tianjin municipality (P. Holt in litt. 2012). Disturbance of nest-sites is a problem, particularly through the collection of lugworms on tidal flats in China, and by photographers in South Korea. The disturbance of adults results in increased predation of eggs and chicks. In China, eggs are sometimes collected by fishers. Unfavourable weather conditions threaten birds and nests at Yancheng.


Conservation Actions Underway
CMS Appendix I. The key nesting sites in China are all nature reserves. Wintering sites at Manko (Japan), Mai Po (Hong Kong), and Xuan Thuy (Vietnam) are all protected areas. The species is classed as Vulnerable in China and therefore receives full legal protection. Conservation Actions Proposed
Conduct surveys in North Korea for potential breeding sites. Expand the Yellow River Delta Nature Reserve (China), to include additional nest-sites. Establish protected areas at the wintering sites of Wenzhou-Yueqing bays (China), Tutu estuary, Hanpao and Aoku (Taiwan), Suncheon-Kwangyang bays (South Korea), Daijyu-garami, Hakata Bay and Sone (Japan). Provide management plans for coastal wetlands to promote their conservation and prevent the expansion of smooth cordgrass through active management measures (Jiang et al. 2010). Ensure full legal protection for this species.

References
Bai Qing-Quan. 2008. The finding of Kyushu banded Saunders's Gull in Dandong. China Crane News 12(1): 53.

BirdLife International. 2001. Threatened birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.

Brazil, M. 2009. Birds of East Asia: eastern China, Taiwan, Korea, Japan, eastern Russia. Christopher Helm, London.

Cao, L.; Barter, M. A.; Wang, X. 2008. Saunders's Gull: a new population estimate. Bird Conservation International 18(4): 301-306.

Jiang Hongxing. 2007. The color flag and surveys of Saunders's Gull. Newsletter of China Ornithological Society 16(2): 35-36.

Jiang, H. X.; Hou, Y. Q.; Chu, G. Z.; Qian, F. W.; Wang, H.; Zhang, G. G.; Zheng, G. M. 2010. Breeding population dynamics and habitat transition of Saunders's Gull Larus saundersi in Yancheng National Nature Reserve, China. Bird Conservation International 20(1): 13-24.

Li Xiao-Jing; Li Yu-Xiang; Li Feng-Li. 2007. A Saunders' Gull banded in Shuangtai Esturay of Liaoning was found in Gunsam Bay of POK. China Crane News 11(2): 25.

Liu Yang; Holt, P.; Zhang Zhengwang. 2007. Wintering records of Saunders's Gull in Bohai Bay, China. Journal of the Yamashina Institute for Ornithology 38(2): 100-103.

Robson, C. R. 2002. From the field - China. Oriental Bird Club Bulletin 36: 64.

Further web sources of information
Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).

Text account compilers
Anderson, O., Benstead, P., Bird, J., Chan, S., Khwaja, N., Peet, N., Pilgrim, J., Taylor, J.

Contributors
Hark-Jin, K., Holt, P., Liu, Y.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2014) Species factsheet: Larus saundersi. Downloaded from http://www.birdlife.org on 19/04/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/04/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Saunder’s gull (Larus saundersi) 0

Key facts
Current IUCN Red List category Vulnerable
Family Laridae (Gulls and terns)
Species name author (Swinhoe, 1871)
Population size 14400 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 68,200 km2
Country endemic? No
Links to further information
- Additional Information on this species