|Scientific Name:||Thalasseus bernsteini|
|Species Authority:||(Schlegel, 1863)|
Sterna bernsteini Schlegel, 1863
|Taxonomic Notes:||The BirdLife Taxonomic Working Group is aware that phylogenetic analyses have been published which have proposed generic rearrangements which may affect this species, but prefers to wait until work by other taxonomists reveals how these changes affect the entire groups involved.|
|Red List Category & Criteria:||Critically Endangered C2a(i,ii); D ver 3.1|
|Contributor(s):||Chan, S., Hansbro, P., He, F., Kennerley, P., Liao, S., Liu, Y., Morning, F., Morris, P., Nisbet, I. & Yang, L.|
|Facilitator/Compiler(s):||Benstead, P., Bird, J., Calvert, R., Crosby, M., Lascelles, B., Peet, N., Pilgrim, J., Symes, A. & Taylor, J.|
This poorly known species qualifies as Critically Endangered because it is estimated to have a tiny population, which is in decline owing to egg-collection, disturbance and the loss of coastal wetlands.
Thalasseus bernsteini is a poorly-known species, recorded breeding recently at only two sites on the eastern coast of China: Zhejiang and Fujian Provinces and, outside the breeding season, in Indonesia, Sarawak, Malaysia, Taiwan (China), Thailand and the Philippines (BirdLife International 2001). In June-July 1937, a total of 21 specimens were collected on islets off the coast of Shandong, where it was presumably breeding, indicating that it was locally not uncommon in the past; however, surveys conducted in June-July 2006 suggest that the regional breeding population has been extirpated from the coast of southern Shandong (Chen Shuihua et al. 2009, Liu Yang et al. 2009). Until the rediscovery of the breeding sites on Matsu Islands, Fujian and Jiushan Islands, Zhejiang, the only records were from China, in Hebei in 1978 and Shandong in 1991, with a possible record from peninsular Thailand in 1980.
In summer 2000 four adults and four chicks were found amongst a tern colony in the Matsu Archipelago off the east coast of mainland China (but administered by Taiwan). Breeding again took place in 2003, and in 2006 5-7 birds, including a pair of adults and a juvenile, were present (Candido 2006), with a total of 20, including three chicks, reported in 2008 (Hansbro in litt. 2008). In 2010 there were 15 adults and three nestlings at Matsu; there were six adults in 2011 and only four adults (with no successful breeding) in 2012 (S. Chan in litt. 2013).
A small group was also found breeding at Jiushan off the Zhejiang coast in 2004 (Kejia et al. 2004), but none bred there in 2005 or 2006; four pairs were recorded in 2007 but all eggs were collected by local people (Chen Shuihua 2007). Two pairs raised two young in 2008, but there was no breeding at Juishan from 2009-2012 (S. Chan in litt. 2013). However, a small group, considered to be a former breeding group of the Jiushan birds, were found breeding at the Zhoushan Wuzhishan Archipelago nature reserve in 2008 (Shuihua Chen 2008, Chen Shuihua et al. 2010), with a maximum of 12 adults and three nestlings there in 2011 and eight adults and four nestlings in 2012 (S. Chan in litt. 2013). In 2013 Tiedun Dao islet in the Jiushan Islands was restored as a seabird colony (BirdLife International 2013). Vegetation was cleared, 300 tern decoys were placed on the island and solar-powered playback systems were used to play contact calls of Great and Chinese Crested Terns. By late July 19 adult Chinese Crested Terns (the largest count since rediscovery) and 2,600 Great Crested Terns were present, and by September at least one juvenile Chinese Crested Tern had successfully fledged.
Surveys of the coasts of Shandong and Zhejiang in 2003-2007 suggested that the breeding colonies on the Matsu and Jiushan Islands were the only ones still extant (Chen Shuishua et al. 2009). One to 11 birds (thought to be birds from the Matsu colony) are present from April to September at the Min Jiang estuary, Fujian. Since 2008, a small number of putative hybrid S. bernsteini x S. bergii have also been recorded and photographed at Min Jiang estuary (Chen Lin and He Fenqi 2011), with two recorded at the Matsu Archipelago in June 2011 (Wang Jianhua and He Fenqi in press). The species's movements and wintering grounds remain poorly understood, but heightened awareness in Taiwan (China) has resulted in several records of 1-2 birds using the Pachang River outside the breeding season since 1998 (P. Kennerley in litt. 2003), and more recently in 2004 at Chongming Dongtan National Nature Reserve, Shanghai (Kejia et al. 2004), and the Xisha Archipelago, indicating that it may winter around islands in the South China Sea. An individual was recorded on Palau Lusaolate, north Seram, Indonesia in December 2010 (C. Robson in litt. 2010, Robson 2011).
It is thought that the species's known population can be divided into three small flocks: the Taiwan Straits flock, Zhoushan Archipelago flock and northern Chinese coast flock (Jiang Hangdong et al. 2010).In addition, a record of three birds at Rizhao, southern Shandong, in September 2011 adds support to the theory that another flock still exists along the coast of northern China (Qin Yupin and He Fenqi 2011), although these may be post-breeding stragglers from a known colony (Liu Yang in litt. 2012). There is also a very northern record from Tangu, Tianjin, in September 2008 (per Liu Yang in litt. 2012). The total current population is unknown, but is presumably tiny given the paucity of recent records.
Native:China; Indonesia; Malaysia; Philippines; Taiwan, Province of China; Thailand
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The number of breeding adults varies each year, ranging from 12 in 2012 to 26 in 2004. Given this the total number of mature individuals is likely to number fewer than 50, and perhaps most likely 30-49 (S. Chan in litt. 2013).|
|Habitat and Ecology:||Records indicate that it is exclusively coastal and pelagic in distribution. In China (including Taiwan), it has been found on offshore islets (breeding) and tidal mudflats.|
|Major Threat(s):||Many coastal wetlands in its presumed breeding range in eastern China are affected by large-scale development projects and, in China, seabirds are exploited for food. The apparent extirpation of the population that formerly bred along the coast of southern Shandong is thought to be linked to the colonisation and development of its breeding islands since the 1950s (Liu Yang et al. 2009). Breeding failures in 1999, 2001, 2002, 2003 and 2005 at the Matsu tern colonies, and in 2007 in Zheijang Province may have been attributed to fishermen landing to collect shellfish and tern eggs (Candido 2006, Anon 2007a, Chen Shuishua et al. 2009) and this is probably by far the most serious immediate threat to the species. The going rate for one seabird egg in Zhejiang more than doubled between 2005 and 2007, encouraging more people to enter the egg-collecting trade (Anon 2007a). Putative S. bernsteini x S. bergii hybrids have been recorded and photographed at Min Jiang estuary since 2008 at least, thus hybridisation may be a significant threat to the population (Chen Lin and He Fenqi 2011). Oil spills are another potentially serious threat: a partly-oiled pair were present on the Min Jiang estuary in 2010 (P. Morris in litt. 2010). Rats are possibly present on Matsu and may predate nesting terns (Anon 2007b). Given its tiny population, natural disasters represent an additional threat, with tern colonies on the Jiushan Islands devastated by two large typhoons in August 2004 (Chen Shuishua et al. 2009, Chan et al. 2010). Over-fishing and disturbance associated with fishing activities and tourism are additional potential threats (Chen Shuishua et al. 2009, Chan et al. 2010). The potential threat from the impact of pollution from domestic sewage and industrial effluent on the species's food supply is no longer considered likely (I. C. T. Nisbet in litt. 2010).|
Conservation Actions Underway
The Matsu colony and surrounding islands were declared a national nature reserve in 2000 and eight islets have been declared 'preserved areas', with no-one allowed to land during the breeding season (Chang Shouhwa and Wang Dustin 2008). The Taiwanese Coast Guard patrols waters around the Matsu Islands and has recently begun seizing fishermen's nets if they are caught egg-collecting - this appears to be a major deterrent as there has been no recorded egg loss since (Anon 2007b). Reclamation at Min Jiang estuary was halted in 2006 and the site is now a provincial-level reserve (F. Morning in litt. 2008). In Thailand, it is nationally protected, and the locality where it was historically recorded is protected as the Laem Talumphuk Non-Hunting Area. A Special International Meeting of the Pacific Seabird Group was held in Lukang, Taiwan, in October 2007, at which the Chinese Crested Tern Working Group was formed and various conservation actions were discussed (Anon. 2007b).
An 18-month 'Critically Endangered Chinese Crested Tern' project began in July 2008, aiming to locate undiscovered breeding colonies and feeding areas in Fujian Province, and is also conducting education and awareness work at schools and local communities around key sites in northern Fujian, and raising awareness of the need for strengthened law enforcement and other actions among stakeholders in Fujian and Zhejiang Provinces (BirdLife International 2009). In April 2009, 20 participants attended the Chinese Crested Tern Conservation Meeting across the Taiwan Straits in Fuzhou City, Fujian (Cheung 2010). Amongst the coordinated conservation actions agreed were synchronised surveys to be carried out twice a month from June to August 2009 in the Matsu Islands and Min Jiang estuary to confirm the total number of individuals off the coast of Fujian, surveys for new breeding sites along the eastern coast of mainland China in the next few years, and investigation of migration routes and basic training for nature reserve staff and volunteers. A public seminar and photo exhibition were held in the public library of Fujian in the same month to raise awareness of the species and major threats. In October 2009, further awareness-raising activities were conducted in schools in coastal areas of Zhejiang and Fujian (Cheung 2010). Environmental education work is on-going (Hong Kong Bird Watching Society in litt. 2011). In November 2009, an international symposium on the Chinese Crested Tern was held in the Matsu Islands and was attended by almost 100 delegates (Chen Shuihua 2009, Gill 2010). A Species Action Plan was published in 2010 (Chan et al. 2010).
In 2013 Tiedun Dao islet in the Jiushan Islands was restored as a seabird colony (BirdLife International 2013). Vegetation was cleared, 300 tern decoys were placed on the island and solar-powered playback systems were used to play contact calls of Great and Chinese Crested Terns. By late July 19 adult Chinese Crested Terns and 2,600 Great Crested Terns were present, and by September at least one juvenile Chinese Crested Tern had successfully fledged.
Conservation Actions Proposed
A CMS International Single Species Action Plan (Chan et al. 2010) recommended a number of actions, including to: Conduct surveys at its former localities, both in the presumed breeding and non-breeding ranges, and at other potentially suitable breeding sites in China. Take immediate conservation measures to safeguard any sites found, especially nesting colonies. Upgrade the level of protection afforded to Min Jiang Estuary. Monitor the known breeding colonies, while taking care to avoid disturbance. Enforce a ban on landing on the breeding islands. Stop exploitation of the species, ensuring no eggs are taken - posting a warden at the Matsu Islands would be ideal; however this may not currently be possible for political reasons. Survey potential wintering areas and migration sites, including islands in the Seram Sea and Banda Sea (Robson 2011). Lobby to reduce the amount of pollution from industry. Strengthen the species's legal protection status. Conduct an education/awareness raising campaign to raise the profile of the species. Implementation of suggested actions is needed by all range countries. Study the species's breeding ecology, movements and genetic diversity (Liu Yang et al. 2009). Monitor the breeding colony on the Wusishan Archipelago.
|Citation:||BirdLife International 2013. Thalasseus bernsteini. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 07 July 2015.|