Chinese crested tern
Chinese crested tern (scientific name: Thalasseus bernsteini): Is a medium-sized waterbird with a body length of 38–42 cm. The forehead, crown and crown feathers are black, the upperparts are pale grey, the wings are gray, and the outer primary flight feathers are black. The tail is white and deeply forked. The underparts are white. The mouth is yellow with a wide black tip. Feet black. Non-breeding feathers are similar to summer feathers, but the forehead and crown are white. Iris brown. The beak is slightly thicker than that of terns, and slightly curved, yellow in color, with black subterranous spots at the tip.
It inhabits coastal islands, breeds on the coast of Shandong, China, and migrates and winters off the coasts of Guangdong, Fujian, the Philippines, Borneo and the Malay Peninsula. It is a summer migratory bird in the northeast of China and a winter migratory bird in the south. It feeds mainly on fish. It also eats crustaceans, molluscs, and other marine invertebrates. Foraging is mainly on the surface of the water. It is found in China, Indonesia, South Korea, Malaysia, the Philippines and Thailand.
The Chinese crested tern, the rarest bird in China, is listed as a critically endangered species on the Red List of Birds of the World, and is the most severe level of danger of extreme extinction. It was first discovered and recorded in 1861, but remained very rare until 2000, when it was generally considered extinct. However, in 2000, 4 adult birds and 4 young birds were rediscovered in the Matsu Archipelago off the coast of Fujian Province, which became the great news of the ornithological community that year. In 2004, another breeding colony was also found in the Leek Shan Archipelago off the coast of Zhejiang Province, two of the remaining groups in the world.
The risk factors for the Chinese crested tern are pollution and damage to their habitat. Global dependency protection (Collar et al., 1994). Very rare. It was previously thought to breed off the coast of Shandong, China. In 2000, it was found to breed in Matsu, Fujian Province. The species is a critically endangered species that was considered extinct in 2000 before four adult birds and four chicks were discovered near a colony of large crested terns in Lianjiang County, Fujian Province, China. They have also been found off the northern coast of China's Shandong province, the Philippines, Thailand, Indonesia, and Sarawak. Another breeding ground was discovered in the Lishan Archipelago of Zhejiang Province in 2004.
The decline in its number was blamed on the indiscriminate collection of bird eggs. They were able to survive in Matsu, possibly because Matsu used to be a military restricted area and access to the area was restricted. Matsu has become a nature reserve. They are still possible off the coast of Chinese mainland and Taiwan: migrating terns were once found in Bapao Creek.
The Chinese crested tern is the rarest of the gulls and is one of the most endangered bird species in the world. Since they were named in 1863, by 2000, there have been only 6 definitive observations of them. Because of their rarity and mystery, they are called "mythical birds" by scholars and experts. In addition to the summer specimens collected in Shandong, China, specimens were also collected in Guangdong, Fujian, Indonesia, Malaysia, Thailand and the Philippines during the spring and autumn and winter. It breeds on matsu islands in Taiwan and the coastal area of Zhejiang, and forages and moves in the wetlands of Minjiangkou in Fuzhou, Fujian Province. Migrating and overwintering in the southern coast of China and Southeast Asia. Since there have been no reliable reports since 1937, it is thought that the species may have been extinct, but in 1978 and 1980 it was found in Hebei and Thailand, respectively, and three were seen in the Yellow River estuary wetlands in 1991. It was not until 2000 AD that its breeding record was discovered in the Matsu Islands Tern Sanctuary, which was the first place in the world to find a breeding record. There are fewer than 100 left in the world, and due to their scarcity, they are endangered, and they are often mixed in flocks of crested terns and are not easy to observe, so they are also known as "mythical birds".
For the first time, the Chinese scientific expedition conducted an expedition to the Chinese crested tern in five consecutive breeding seasons. The results show that the global total number of this rare bird has halved in three years and has fallen to less than 50 (2010).
The indiscriminate collection of bird eggs is a major threat to the species, leading to breeding failures in the Chinese crested tern on Matsu Island in China and in Jiushan Island in 2007 in 1999, 2001, 2002, 2003 and 2005. For 45 nesting breeding attempts between 2004 and 2013, bird egg harvesting accounted for 44% of nest failures (Chen et al., 2015). Between 2005 and 2007, the market value of bird eggs in Zhejiang Province more than doubled, spurring more people to enter the egg picking industry (Anon 2007a). Despite increased patrols, poaching continues to occur. Typhoons also lead to higher nesting failures, with studies found that 48% failed between 2004 and 2013. Many factors attributed to typhoons (58%). The synergistic effects that these two threats may have on species. Protecting breeding sites can reduce mortality, for example, during a typhoon during the 2015 breeding season, Tideun Dao reduced chick mortality by 5% simply because the maintenance of vegetation enabled chicks to move to shore, but not all breeding sites were protected in this way.
Fishing for shellfish near breeding grounds can also interfere with bird reproduction. Fishing activities in the wintering areas of eastern Indonesia, including explosives fishing, pose an additional threat, but their extent is unclear. Tourism interferes with the breeding of seabirds in Matu, and although people are forbidden to go to the island, there is no direct evidence of a quantitative impact. Human activities also attest to the loss of species in the coastal areas of Shandong, China, which is related to human activities and development on the island since the 1950s. Due to the construction of houses, wind farms, lighthouses and other buildings, the Chinese crested tern lacks suitable breeding habitat.
Fish deaths due to the proliferation of harmful "red tide" algae caused by industrial pollution in areas where the species live has reduced the food supply needed to breed seabirds. Invasive species also pose a threat, with the Emperor Cobra King and King Snake both devouring tern eggs, chicks and adult birds trapped on nesting islands. Rats have been recorded and found at breeding sites (Mazu, Jishan and Wuzhishan Islands) that prey on tern eggs and chicks, with no direct evidence of an effect on Chinese crested terns, but it has been found that rats affect mixed flocks of birds, including Chinese crested terns. Due to the small size of the species population, even very low predatory levels can have a significant impact.
The Chinese crested tern has always been a rare and mysterious bird, and the Chinese expedition has stepped up its efforts to protect it, but it does not seem optimistic, hoping for better news. Hybrids of the Chinese crested tern and the great crested tern have been documented and photographed since 2008 at the mouth of the Minjiang River and at all 3 breeding grounds off the coast of China. Given the very small size of the population, this could be a major threat to the Chinese crested tern