TAIPEI: After about a year of research, experts in Taiwan say they have succeeded in tracing the migration patterns of the endangered gray-faced buzzard, the Forestry Bureau under the Council of Agriculture said yesterday.

The research team, financed by the Forestry Bureau, released its findings showing that gray-faced buzzards, Asian birds of prey, usually stop over in Taiwan every October on their way south to winter in the Philippines.

The raptors, known scientifically as Butastur indicus, then fly north in the spring. They make another stop in Taiwan before continuing on to the Sino-Russian border near Heilongjiang province or to the Democratic People's Republic of Korea (DPRK), where they breed, the researchers found.

Between 15,000 and 35,000 gray-faced buzzards stop in Taiwan along the route each year, but prior to the latest research, little was known about their migration habits.

Keen to find out more about the birds' migration patterns, the team, including researchers from Academia Sinica and the non-profit Raptor Research Group of Taiwan, tagged five adult buzzards caught in Kenting National Park in southern Taiwan and the Mt. Bagua National Scenic Area in the central county of Changhua in October 2008 and March of this year.

The five birds were dubbed Cape No 1-5 and then released.

With the help of the satellite transmitters attached to the birds, researchers were able to track the movements of Cape No 1, No 2 and No 5 and trace precisely their previously mysterious migration routes.

The researchers found that as of October 12, the three birds had passed through Taiwan and two were en route to the Philippines for the winter, while one had already landed there.

Cape No 1 was found to have traveled over 12,000 km in a broad circle covering the southern Philippines at the southernmost tip and Heilongjiang province at the northernmost tip, with Taiwan as a midway stop and a mountainous area in Jilin province on the mainland as a rest stop for breeding in early June, according to the bureau.

Although Cape No 1 arrived at its breeding ground later than Cape No 2 and No 5, it overtook the other two tagged birds and was the first to land in the Philippines after a year-long migratory flight.

It took refuge on a tiny island off Guangdong province in March during the strong northeast monsoon, recovering its strength before heading further north around the end of May, the researchers were able to determine.

Meanwhile, Cape No 2 and No 5 also flew over 12,000 km in a migration circle, stopping at breeding grounds in a rural area of the DPRK.

The researchers lost contact with Cape No 3 and No 4 somewhere over the ocean as the birds were flying north and their transmitters remained silent, according to the Forestry Bureau.

The recent findings - the first migration data on gray-faced buzzards - are a good scientific foundation for further migration research, the officials said.

The gray-faced buzzard is listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) and is also protected as a Rare and Valuable Species under Taiwan's Wildlife Conservation Act, according to the Forestry Bureau.

The adult gray-faced buzzard stands 41-46 cm long, has a gray head, breast and neck, a white throat, a black moustache and mesial stripes, brown back and upper wings, and brown bars on white underparts and underwings. The juvenile is brown and mottled above, pale below with brown streaks, and has a broad white supercilium and brown face.

Generally, the southern migration areas of gray-faced buzzards are limited to Southeast Asia. In summer, they breed in eastern areas of Asia, including northern China, the Korean peninsula, an area southeast of the River Ussuri in Russia, and Japan. When autumn comes, they migrate south to the southeastern region of the Chinese mainland, Indochina, the Philippines, Borneo, the Celebes and New Guinea, although the migration routes are still not clear.

China Daily/CNA

(HK Edition 10/16/2009 page2)