Journal of the Yamashina Institute for Ornithology
Online ISSN : 1882-0999
Print ISSN : 1348-5032
ISSN-L : 1348-5032
Volume 38 , Issue 2
Showing 1-10 articles out of 10 articles from the selected issue
Original Articles
  • Yasuo Ezaki, Takashi Bamba, Masanobu Hotta
    2007 Volume 38 Issue 2 Pages 67-79
    Published: March 20, 2007
    Released: March 20, 2009
    The breeding ecology of forest-dwelling Grey Buntings Emberiza variabilis, particularly territorial fidelity and home range overlap, was studied in a beech forest from 1996 to 1999. Adult males arrived in the study area significantly earlier than young males; females arrived six to ten days later than males. During the 1999 breeding season, 10 of 12 males established territories, mated and bred in the study area. Conflicts between the males were frequent from early May to May 15, but decreased drastically thereafter. Although song areas of some males overlapped before May 16, they separated clearly on and after that day. Six of the 10 established males established territories on the same site where they had bred the previous or earlier years. Thus, males that bred in the study area returned to the same territories. Their home ranges overlapped extensively, even after their song areas were separated. Twenty-three nests were found during the 1999 breeding season. The male parent was identified in 17 of these nests, and they were the ten established males. In those nests, the female parent also was identified. The result was that the same pairs repeated breeding after failure. Six other nests were renesting of these pairs or the nests of other pairs at the edge of the study area. The mating system of the Grey Bunting is suggested to be social monogamy.
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  • Masashi Murakami, Shigeo Ohshima, Satoshi Yamagishi
    2007 Volume 38 Issue 2 Pages 80-89
    Published: March 20, 2007
    Released: March 20, 2009
    The role of stream insect in sustaining a riparian bird community was studied in Kakita Stream, central Japan. Kakita Stream is a spring-fed stream with constant water discharge and temperature throughout the year. Seasonal dynamics of aquatic insect emergence and the dynamics of bird abundance in riparian forest were monitored at Kakita Stream and compared with a control site, Kano River, which is an ordinal stream showing greater fluctuations in water temperature and discharge. Higher abundances of aquatic insect emergence were observed at Kakita Stream compared with Kano River, especially in winter. Kakita Stream acted as a wintering place for many forest birds, as evidenced by the higher abundance of birds compared with the Kano River site. In summer, however, there was no difference in abundance between the Kakita and Kano sites, indicating that the riparian forest of Kakita Stream did not act as a better breeding place than Kano River. This may be because the area of riparian forest around Kakita Stream is insufficient for forest birds to breed. This finding might suggest ways in which the Kakita Stream, including the riparian forest, can be managed optimally in the future.
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Short Note
  • Sadao Imanishi, Yoshimitsu Shigeta, Toshiyuki Yoshino
    2007 Volume 38 Issue 2 Pages 90-96
    Published: March 20, 2007
    Released: March 20, 2009
    On 21 July 2002 at Nobeyama Plateau in Nagano Prefecture, central Japan, we found an interspecific pair comprising a male Brown Shrike Lanius cristatus superciliosus and a female Thick-billed Shrike L. tigrinus, feeding their hybrid young aged about five days after fledging. The male and female parents and one hybrid young of about 28 days old were caught on 21 July, 22 July, and 31 July 2002, respectively. The parental plumage was typical for their respective species. The hybrid's plumage was entirely juvenile, with the remiges and rectrices growing. The juvenile plumage of the hybrid resembled that of Brown and Thick-billed Shrikes in some parts, but differed in many parts, notably in the colour and markings of the greater coverts and the face-mask. At the study area (ca. 15 km2) in 2002, only this interspecific pair and three pairs of Brown Shrikes were found breeding: no pairs of Thick-billed Shrikes bred. This is the first authentic case of hybridization of Brown and Thick-billed Shrikes in Japan.
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