南大東島のノスリ新亜種について

抄録

Type: Possibly male, a live specimen at examination on Oct. 22, 1970. Six years and fivemonths old. Collected on May 4, 1964 as new-born chick by Mr. K. Yonamine on Minamidaito I., Borodino Is. and has been reared and being kept alive by Mr. Masao Oshiro in Naha City, Oki-nawa I.
Measurements: Total L. 470mm, Wing Exp. 1050mm, Wing 330mm (Natural), 340mm (Pres-sed), Tarsus 64mm, Culmen 31mm (Entire), 24mm (From cere). For comparison, the measurements in 10_??__??_, 6_??__??_ of japonicus (from Japan) are: Wing (Natural) _??__??_ 348-368 (Av. 354. 5)mm, _??__??_ 363-373 (Av. 367. 6)mm; Tail _??__??_ 187-210 (Av. 195.6)mm, _??__??_ 205-210 (Av. 207.5)mm (Measured by the author).
Description: Similar to Bnteo buteo japonicus as a whole, but is generally more reddish, the tectrices and rectrices being almost chestnut color with distinct regular dark bands. The sides of head, supercilliaries and ear-coverts, as well as foreneck at crop region are distinctly tawny buff.The typical japonicus is buffy white in these regions, and wings and tail lack chestnut color(though there is a weak wash of this color on primaries) and with less regular dark bands, the tail being usually uniformly pale greyish brown. However, the flank pattern is of japonicus-type (Cf. Photos). There is no similarly reddish and so distinctly banded example among Japanese specimens preserved in Yamashina Institute, and is also different from larger-sized continental reddish and banded phase.
Range: Minamidaito I., Borodino Is. (The first record).
Remarks: Having examined only one bird, it is not clear whether its plumage pattern represents whole Minamidaito population. However, it is reasonable that a darker (redder) population has been established on this southern island. It is decidedly smaller in size than japonicus. Its subspecific name is dedicated to Mr. Oshiro who has reared it from chick. The nest was found by Mr. Yonamine with three eggs which soon hatched but a late hatched chick had disappeared when he examined the nest three hours later. The two chicks were taken by him and one of them was given to Mr. Oshiro.