Result of the Cooperative Study of Asian Raptor Migration in Japan


ARRCN Cooperative Study of Asian Raptor Migration in Hazy Project, Japan


ABSTRACT

We investigated raptor migration for the cooperative study of Asian raptor migration in hazy conditions from September 1 to October 30, 1999 in Japan. The data from 36 observation sites from 17 NGOsí and 11 individual observers was obtained by the end of the investigation period. They included the data of three migratory species: the Chinese Goshawk (Accipiter soloensis), the Oriental Honey-buzzard (Pernis ptilorhyncus) and the Grey-faced Buzzard (Butastur indicus). About 440,000 Chinese Goshawks were observed on Tsushima Island from September 1 to 30. Especially, about 340,000 birds migrated on September 25. It seems that some of these birds migrated to Taiwan via West Kyushu. About 7,800 Oriental Honey-buzzards were observed on Fukue-shima from September 23 to October 6. It seems that their flocks migrated in a western direction, the Shanghai district in China. About 32,000 Grey-faced Buzzards were observed in Kohyama-cho, Kagoshima Prefecture from September 27 to October 19. In addition, it seems that most of the Grey-faced Buzzards migrated to Taiwan via the Miyako Islands.


RESULTS AND DISCUSSIONS

Data from 36 observation sites from 17 NGOs' and 11 individual observers was obtained until end of the investigation period. I will report on three important species that migrate to Southeast Asia: the Chinese Goshawk, the Oriental Honey-buzzard and the Grey-faced Buzzard.


1.       Chinese Goshawk Accipiter soloensis

It seems that the Chinese Goshawk does not breed in Japan. They breeds on the Korean Peninsula and in Northeast and Southeast China. It seems that individuals bred on the Korean Peninsula and in Northeast China might pass Japan during the autumn migration period. They would start to migrate in early September every year, on a route discovered to be Korean Peninsula to Taiwan via West Kyushu, Japan (Fig. 1). It is said that their wintering area is Malaysia and Indonesia. The migration peak of the Chinese Goshawks generally occurred in the middle of September in north Kyushu. Continuous observation data at two sites was obtained (Fig. 2). About 440,000 Chinese Goshawks were observed in Tsushima Island from September 1 to 30. Especially, about 340,000 birds migrated on September 25. In 1999, the migration peak was extremely delayed because of a typhoon. It seems that some of these birds migrated to Taiwan via West Kyushu. A new migration route from Tsushima to Southeast China may be found in the future.


2.      Oriental Honey-buzzard Pernis ptilorhyncus

Oriental Honey-buzzards have bred within wide range in Japan. They begin to migrate in the middle of September. They were known to migrate from the central part of Honshu to Hukue-shima via north Kyushu (Fig. 3). The migration peak of Oriental Honey-buzzards usually occurs at the end of September in north Kyushu. Vital continuous observation data was obtained from three sites this time (Fig. 4). About 7,800 Oriental Honey-buzzards were observed in Fukue-shima from September 23 to October 6. It suggests that Fukue-shima is on a main migration route of these birds, and that most Oriental Honey-buzzards flew away toward a western direction; the Shanghai district in China (Inoue, 1998). It seems that they stay at Indonesia or Malaysia for wintering, similar to Chinese Goshawks.


3.      
Grey-faced Buzzard Butastur indicus


Grey-faced Buzzards have been known as migrating raptor from long ago to the Japanese people. They have bred in the forests from Kyushu to Tohoku in Japan. They begin to migrate in the middle of September. In the western part of Honshu, it is known to reach south Kyushu via two main routes; on the Inland and the Pacific Ocean coast (Fig. 5). The migration peak of Grey-faced Buzzards was generally occurred middle of October in south Kyushu. In 1999, it was on October 10 in Kohyama-cho, Kagoshima Prefecture and on October 16 in the Miyako Islands, Okinawa Prefecture. About 32,000 Grey-faced Buzzards were observed in Kohyama-cho from September 27 to October 19 (Fig. 6). It seems that most of the Grey-faced Buzzards migrated to Taiwan via the Miyako Islands. It seems that they stay at Okinawa, Taiwan, the Philippines, Indonesia, Malaysia or other unknown region for wintering.



Fig. 1 Migration Route of Chinese Goshawks





Fig. 3 Migration Route of Oriental Honey-buzzard




Fig. 5 Migration Route of Grey-faced Buzzard






TAIWAN




Raptor Watching in Kenting N.P.

Results
Species Total number Observer Observation period
Chinese Goshawk Accipiter soloensis 42,006 Tsai Yi-Jung 1 Sep. - 31 Oct.
Grey-faced Buzzard Butastur indicus 17,869 Tsai Yi-Jung 1 Sep. - 31 Oct.




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