Threatened Asian Species - Case Studies
Crisis in Sundaic forests hits Rhinoceros Hornbill
One of the most critical conservation issues in Asia is the wholesale clearance of lowland rain forest in the Sundaic (or Sundaland) region in Indonesia, Malaysia, southern Thailand, southern Myanmar and Brunei. As a result of rapid forest loss through commercial logging, clear felling for paper production, and plantation establishment, these lowland forests now contain 28 Threatened and 79 Near Threatened species. These include once relatively common and widespread birds such as Crestless Fireback Lophura erythrophthalma and Large Green-pigeon Treron capellei which are now listed as Vulnerable, and Rhinoceros Hornbill Buceros rhinoceros which is Near Threatened. Nowhere is the crisis facing Sundaic lowland forest more severe than in the Indonesian Island of Sumatra, where the World Bank recently predicted that virtually all lowland forest will have been cleared by 2005.
Wetland loss means Siberian Crane loses ground
Siberian Crane Grus leucogeranus is now listed as Critically Endangered, having previously been listed as Endangered in 1994. Its population is estimated to be 2,500-3,000 and comprises three separate populations. The western population breeds in western Siberia and winters in Iran, and the central population breeds in western Siberia and winters in India. Both the western and central populations are on the verge of extinction as a result of habitat loss and hunting. The much larger eastern population breeds in eastern Siberia and winters in the lower Yangtze basin in south-east China. The main threats to this population are wetland destruction and degradation at staging areas and wintering sites caused by agricultural development and the development of oil fields. The main wintering site in China, Poyang Lake in Jiangxi Province, holds 95% of the global population but is potentially threatened by future hydrological changes resulting from the construction of the Three Gorges Dam and other dams. If the operation of these dams prevents the development of suitable winter feeding conditions for waterbirds at Poyang Lake and other wetlands, Siberian Crane and other threatened species could undergo extremely rapid population declines in the near future.
Black-faced Spoonbill making headway
Black-faced Spoonbill Platalea minor was listed as Endangered in 2001 having previously been Critically Endangered in 1994. It is estimated to number just over 1,000 birds, breeds on islets off the west coast of Korea and China, and has major wintering wetland sites in Taiwan, Hong Kong and Vietnam. An action plan and workshops involving all major range countries has resulted in co-ordinated actions, including satellite-tracking and field surveys which have added considerably to knowledge of the migratory movements and identified some important breeding and passage sites. The satellite-tracking located several important breeding colonies in the Demilitarised Zone (DMZ) which separates North Korea and South Korea, where the current security situation provides a safe haven for wildlife. The Tsengwen estuary in Taiwan, which supports almost half of the global wintering population, was designated as a new protected area in 2002. However, it is feared that the species may be losing feeding habitat on its breeding grounds because of reclamation of the inter-tidal mudflats around the Yellow Sea, and coastal development may also be affecting its poorly known wintering grounds along the coast of mainland China.
Crested Ibis’ small population increases
Crested Ibis Nipponia nippon is now listed as Endangered having been Critically Endangered in 1994. It appeared to be close to extinction in the early 1980s, but a small wild population was discovered in 1981 in a remote region of central China. This has steadily increased as a result of careful protection by the government and local people, including protection of nest sites and maintenance of rice-fields as feeding sites. The estimated wild population at the end of the breeding season in 2002 was 200 birds.
Vultures in peril
Three species of vulture – White-rumped Gyps bengalensis, Indian G. indicus and Slender-billed G. tenuirostris – have suffered extremely rapid declines in the Indian subcontinent, and are now listed as Critically Endangered. These birds play a crucial role in the disposal of carrion, and where they have declined they are being replaced by packs of feral dogs, which could lead to an increased rabies problem. Large number of dead and dying vultures have been found, leading researchers to consider the possibility of a mystery disease, but recent research in Pakistan has indicated that a veterinary medicine might be the cause. The on-going research needs to be continued, to determine the emergency measures needed to prevent the extinction of these three species.
Straw-headed Bulbul – a victim of the cage-bird trade
Once widespread and common in suitable habitat throughout the Sundaic (or Sundaland) lowlands, the Straw-headed Bulbul Pycnonotus zeylanicus has declined dramatically. It is now thought to be extinct in peninsular Thailand, virtually extinct throughout Indonesia, and is much reduced in numbers elsewhere leading to its listing as Vulnerable. The principal reason is large-scale trapping for the cage-bird trade, because of its celebrated song.
Chinese-crested Tern – surveys required
Chinese Crested-tern Sterna bernsteini was known only by a handful of scattered records in east Asia, and was feared extinct until four nesting pairs were located in a tern colony on the Mazu Dao (or Matsu) islands off the coast of Fujian Province in China in 2000. The Taiwanese authorities which administer the islands are taking measures to prevent disturbance at the nesting site. Surveys are required to locate further nesting colonies on other potentially suitable islets off the coast of China. It is now listed as Critically Endangered.
Red-crowned Crane – still needs better protection
The Endangered Red-crowned Crane Grus japonensis has a resident population in eastern Hokkaido, Japan, which declined to near extinction at the turn of the twentieth century, but has since gradually recovered thanks to careful conservation measures. The larger, migratory continental population is thought to be declining because of habitat loss on the breeding grounds in north-east China and the Russian Far East, and at the wintering sites on the Korean peninsula and the east coast of China. Improved protection of these sites, including through the work of the North-East Asia Crane Site Network, is essential for this species and several other threatened waterbirds.
Habitat loss & hunting hit Green Peafowl
The Vulnerable Green Peafowl Pavo muticus is a spectacular pheasant that was once widespread and abundant in South-East Asia and the island of Java in Indonesia. It has declined alarmingly in many parts of its former range as a result of habitat loss, hunting and persecution. For example, it is believed to be extinct in peninsular Thailand and Malaysia and to have declined substantially in China and Indochina, while there is little recent information on its status in Myanmar. The remaining populations need to be rigorously protected, in particular to minimise hunting pressure.
Forest Owlet rediscovered
The Critically Endangered Forest Owlet Heteroglaux blewitti was known only by a handful of nineteenth-century records from central India, until preliminary investigations for Threatened Birds of Asia: the BirdLife International Red Data Book helped guide the survey that led to its rediscovery in 1997. There are now recent records from four localities, including two of those where it had been recorded in the nineteenth century. None of these four sites is in a protected area, and improved protection and forest management is required, backed up by further research and community awareness initiatives.
Gurney’s Pitta back from the brink
Gurney’s Pitta Pitta gurneyi was listed as Critically Endangered in 2001, as the only known population was of 23 individuals at a single locality in Thailand, where forest degradation is a continuing threat. However, the species was rediscovered in southern Myanmar in 2003, following a gap in records of almost 90 years. It was found at four localities in a region of Myanmar with a low human population density and extensive lowland forests. Many of these forests are scheduled to be converted to oil palm plantations, and in the longer term it is likely that the human population will increase and forest will be converted to agricultural land. It is vital that new protected areas are established to ensure the long-term future of some extensive areas of Gurney’s Pitta's lowland forest habitat.
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