Most closely related to Cory's
and Cape Verde Shearwaters.
Resembles Cory's Shearwater
in size, structure, coloration and flight action. Slightly less heavy looking
with thinner bill. Whitish head contrasts with dark brownish streaking
on hindcrown and nape. The dark flight feathers contrast with the paler
wing coverts and scapulars. Pale friges to the feathers of the upperparts
gives a scaley appearance. Distinctive dark (streaked) carpal patch on
the 'hand' of the underwing - this is white in Cory's Shearwater. Noticable
contrast between the dark primary/secondaries and white underwing coverts.
Where and When
Breed in immense numbers in islands of southern Japan (Izu, Ryuku, Daito and Senkuku Groups). Also on islands off Korea, East China. Estimates for the Izu Islands are in the order of 3-4 million birds. Often the most abundant seabird. Once collected for food in Japan, but now the species is protected by law. On Mikura, however, birds are collected from time to time to minimize digging of nest burrows that undermine the native trees. Some mortality occurs when birds are trapped in anchovy crawls used to store live caught fish. Significant weather-related wrecks on the Japanese mainland also occur.
Absent from seas off the breeding grounds in the northern winter, when birds migrate to tropical waters of the east and southern China Seas, Philippines, Indonesia and Indian Ocean. Adults leave prior to young. Many reach Papua New Guinea and the Coral Sea, some getting as far south as Sydney, Australia or Sri Lanka and the Abrohlos Islands. The increasing number of records fro Australia may reflect a geunine expansion of the non-breeding range. In the East China sea, attracted to cold water-warm water fronts. Absent from these areas by June when most birds back on breeding grounds.
A rare vagrant to the eastern
Pacific, with a handful of records from Californian waters in September
and October. Possibly associated with fingers of warm water. Also reaching
Eilat at the head of the Red Sea (i.e. Western Palearctic).
Photos and information on the web
in flight Photo by Tony Palliser on his web site. Taken off Wollongong,
NSW, Australia in March.
Stallcup (1990) 2 black and white images
by Alan McBride on p62.
There is a large literature in Japanese, including books devoted to the species such as: Yoshida, N. (1981) Seabirds that Climb Trees. Ubunsha, Tokyo. and Okamoto, B (1972) Calonectris leucomelas on Kanmurijima Island. Komine Shoten, Tokyo.
Stallcup, R. (1990) Ocean birds of the Nearshore Pacific. Point Reyes Bird Observatory Publications.