Oryx



Short Communication

Seasonal change in habitat use in Steller's sea eagles


Mutsuyuki Ueta a1c1, Michael J. McGrady a2p1, Hajime Nakagawa a3, Fumio Sato a4 and Vladimir B. Masterov a5
a1 Research Center, Wild Bird Society of Japan, 2-35-2 Minamidaira, Hino, Tokyo 191-0041, Japan. E-mail: mj-ueta@netlaputa.ne.jp
a2 Raptor Research Center, Boise State University, 1910 University Drive, Boise, Idaho 83725-1516, USA
a3 Shiretoko Museum, 49 Hon-machi, Shari 099-4113, Japan
a4 Bird Migration Research Center, Yamashina Institute for Ornithology, Tsutsumine, Abiko, Chiba 270-1145, Japan
a5 Department of Vertebrate Zoology, Moscow State University, 119899 Moscow, Russia

Abstract

Habitat-use by Steller's sea eagle Haliaeetus pelagicus, categorized as Vulnerable on the 2002 IUCN Red List, was studied using satellite-tracking. This migratory species breeds in eastern Russia and mostly overwinters in Hokkaido, Japan, and the southern Kuzíl islands. Locations of eagles were classified as being river, sea, lake, or other habitat. In autumn, eagles mainly used river habitats, probably because of the availability of abundant post-spawn dead salmon. In winter about one third of eagles continued to be located on rivers, with others on sea coasts and lake sides. During the spring migration and breeding season habitat use by adult eagles probably reflected the variety of habitats in which breeding occurs. At that time, sub-adult eagles were located mainly on the sea coast, probably in places where food supply was sufficient and there were few territorial eagles. In Hokkaido 35% of overwintering eagles used mountain areas for at least some time. It is known that eagles using mountain areas in Japan in winter scavenge upon the carcasses of sika deer Cervus nippon killed by hunters, and are thus exposed to possible lead poisoning. The satellite tracking highlights the importance of several habitats within the range of this species, changes in which could affect its conservation status.

(Received June 4 2001)
(Revised February 13 2002)
(Accepted October 8 2002)


Key Words: Habitat use; Haliaeetus pelagicus; Hokkaido; Kamchatka; lead poisoning; migration; satellite-tracking; Steller's sea eagle.

Correspondence:
c1 Corresponding author Research Center, Wild Bird Society of Japan, 2-35-2 Minamidaira, Hino, Tokyo 191-0041, Japan. E-mail: mj-ueta@netlaputa.ne.jp
p1 Present address: Natural Research Ltd., Am Rosenhügel 59, A-3500 Krems, Austria


Metrics
0Comments