Birds of the world call Taiwan home

By Derek Lee
STAFF REPORTER
Sunday, Jul 08, 2001, Page 17

Steer's liocichla is one of Taiwan's endemic birds. This tiny bird, with a body length of about 17cm, lives mainly in mid-elevation forests. PHOTO: COURTESY OF ZAN WEN-HUI

One of the most overlooked aspects of Taiwan's natural environment is its astounding number of bird species.

Taiwan at the midpoint of the migration routes for many birds flying sometimes as far south as Indonesia, Australia and New Zealand during the winter season or as far north as Siberia during the summer season. As a result, a great number of migrating birds land in Taiwan, including the outlying islands of Penghu, Kinmen, Matsu, Orchid Island, as well as dozens of small surrounding islets, for breeding during spring and summer.

One the most important recent discoveries in bird watching was made in June last year, when a Chinese crested tern, once thought extinct, was spotted on an uninhabited island near Matsu. A year later, on June 6, the global organization Bird Life International sent Richard Thomas, an acclaimed expert in bird watching, to conduct a field survey of these birds in Taiwan.

The discovery made Taiwan the spotlight of the international conservation community, as it had been following the discovery of 130 black-faced spoonbills (黑面琵鷺) in 1985. Partly in response to the discovery of the Chinese crested tern, an international conference on endangered wild bird species will be held in Taipei and Matsu next year.

The tiny Daurian redstart, only 15cm in length, stays in Taiwan during winter. PHOTO COURTESY OF HUANG WEN-SHIN

According to local bird-watching experts Wu Chun-shien (吳尊賢) and Hsu Wei-pin (徐偉斌), at least 450 bird species inhabit Taiwan, either permanently or temporarily. The number represents about one 20th of the more than 9,700 known bird species, which translates to the world's second-highest concentration of bird species per square kilometer after Madagascar. In contrast, China, which is 260 times larger than Taiwan, has only 1,200 bird species.

Wood sandpipers are winter visitors to Taiwan and can frequently be spotted in rice fields, marsh lands and sandbars. PHOTO: COURTESY OF HUANG WEN-SHIN

Varied topography attracts many birds

Taiwan's diverse topography provides the island with vast climatic differences, ranging from tropical and sub-tropical to temperate and cold zones on the more than 200 mountains over 3,000m. The temperature range provides ample food and nesting area for some 158 species of birds. Of these, 14 are Taiwan's so-called endemic species, or species found only in Taiwan.

Among Taiwan's summer visitors, the Oriental cuckoo distinguishes itself by laying its eggs in other bird's nests and leaving the adoptive parent birds to raise its young. The bird can easily be seen in hilly and high- or low-elevation mountain areas in summer PHOTO: COURTESY OF HUANG WEN-SHIN

Each year, Taiwan and its outlying islands offer food and temporary shelter to millions of an additional 290 wild bird species, which come to breed, or transit, or even arrive inadvertently during their seasonal migrations.

Lee Jiannan (李建安) and Lai Po-hsin (賴柏欣) of the Wild Bird Federation Taiwan (中華野鳥學會) told the Taipei Times that the 158 bird species found year-round in Taiwan, called resident birds, account for 39 percent of the total wild bird species. They can be spotted locally throughout the year, and include the Swinhoe's pheasant (藍腹鷳), Formosan blue magpie (台灣藍鵲), white-eared sibia (白耳畫眉), Chinese bulbul (白頭翁),crested serpent eagle (大冠鷲), Steere's liocichla (藪鳥) and the brown booby (白腹鰹鳥). Steere's liocichla are the dominant bird species residing at elevations over 1,000m.

Swinhoe's pheasant is one of the bestknown endemic bird species in Taiwan. These critically-endangered birds are very rarely seen nowadays and tend to be active in low-elevaion forests only PHOTO: COURTESY OF CHEN TSAO-WANG

The winter-migratory birds total 104 species and account for 23 percent of the total number of birds species in Taiwan. Frequently-sighted birds of this kind include the wood sandpiper (鷹斑鷸), daurian redstart (黃尾鴝), grey heron (蒼鷺), green-winged teal (小水鴨) and black-faced spoonbill. These birds arrive in Taiwan in late September to November for winter shelter and return to northern China, Siberia or Alaska to breed in February or March as spring arrives. The black-faced spoonbills stay in the southwest coastal area of Taiwan for the entire winter and their number seems to be growing, to the relief of the international conservation community.

The White-eared sibia is one of Taiwan's endemic birds. It usually appears in small flocks in the canopy and mid-levels of broad-leafed trees in mid-elevation forests. PHOTO: COURTESY OF CHEN TSAO-WANG

Summer-migratory such as the Oriental cuckoo (筒鳥), large hawk cuckoo (鷹鵑), fairy pitta (八色鳥), cattle egret (牛背鷺), eastern collard pratincole (燕行鳥) and tern (燕鷗) are fewer in number and account for only 3 percent, though some studies claim only 1 percent, of birds. They migrate each year from the Philippines, Australia, New Zealand, Indonesia and other southern and equatorial areas in Asia in March or April to breed in Taiwan and leave again in September when daylight hours shorten. Interestingly, Kentish plovers (東方行鳥) are both summer and winter visitors to Taiwan, as different groups come for different seasonal periods.

The rarely-spotted eastern collard pratincole can only be found near coastal areas in summer and is a summer visitor species PHOTO: COURTESY OF SU KUEI-FU

There are 77 species of migratory birds that transit in Taiwan each year, comprising 17 percent of the total number of birds. During either spring or autumn, millions of these birds land in Taiwan to forage and for temporary shelter. Some birds in this category are the brown shrike (紅尾伯勞), the grey-faced buzzard eagle (灰面鵟鷹), the whiskered tern (黑腹燕鷗) and the white-winged black tern (白翅黑燕鷗). The grey-faced buzzard eagles sail into the southern tip of Taiwan in large flocks in late September or early October, filling the sky with their gorgeous wings and distinctive chirps.

The Cattel egret is a favorite subject for painters, as it often stands on the backs of water buffalo. PHOTO: COURTESY OF HE REN-TE

Due bad weather, storms or other causes, a large number of migratory birds become disoriented and land in Taiwan. These so called "vagrant" (迷鳥) often number as many as 90 different species and account for about 20 percent of the wild birds in Taiwan, including such species as the white-tailed sea eagle (白尾海鵰), the cinereous vulture (禿鷹) and the common crane (灰鶴). The appearance of these birds in Taiwan incites a lot of excitement in Taiwan's bird-watching community.

Coming from all around

A concern in Taiwan is the introduction of birds originally intended as pets or smuggled into Taiwan illegally and then released. Once these birds are in the wild, they pose a considerable threat to the natural habitat of native birds and risk tipping the country's ecological balance. Mynas (八哥類) and parrots (鸚鵡類) are the most commonly-captured birds of this type in Taiwan.

In East Asia, winter-migratory birds usually breed in Alaska, Siberia, northern China or Manchuria. In autumn, these birds travel to Taiwan along two major routes. Yen Chung-wei (顏重威) of the National Museum of Natural Sciences (國立自然科學博物館) pointed out one route called the Pacific route, which starts on the Kamchatka Peninsula, the Kuril Islands and Sakhalin Island and skirts the Japanese coast. It then passes through Okinawa and reaches Taiwan. Aquatic birds such as the violet-backed starling (小椋鳥), the blue rock thrush (藍磯鶇), the ruddy kingfisher (赤翡翠) and the grey-faced buzzard eagle all arrive in Taiwan following this route.

The second route is called the Chinese coastal route. Most of the wild birds in Siberia fly first to Manchuria, then cross the Yellow Sea or Korea and Japan to reach Taiwan. In addition to aquatic birds, some terrestrial birds such as the swallow, shrike, thrush, warbler (鶯) and bunting follow this route every year.

Taiwan's birds, such as the fairy pitta, the water cock (董雞), the roseate tern (紅燕鷗), the bridled tern (白眉燕鷗), the greater crested tern (鳳頭燕鷗) and the Chinese crested tern migrate from Vietnam, Cambodia and Thailand to breed in Taiwan. They travel along the coastal regions of Guangxi, Guangdong and Fujian provinces and arrive in Taiwan during the spring season.

Taiwan's coast, which is dominated by mountains and has only a narrow stretch of land to accommodate birds, sees a relatively small number of terrestrial and water birds migrating from Japan in autumn. The west coast, in contrast, has wide intertidal zones, often as wide as 5km. The abundant food there provides for numerous land, wading and water birds.

What wild birds to migrate each year is a question under constant discussion by the international bird-watching community. However, the general consensus seems to be that the phenomenon is closely related to the length of daylight during different seasons which causes physiological changes within the body of migratory birds.

Researchers know, however, that before these birds lift off for breeding grounds or winter shelters, they consume large quantities of food to store up fat in preparation for their migration, therefore, conservation of the natural habitats for these birds is vitally important to maintain Taiwan's diversity of birds.