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.
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.
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.
The ectoparasitic louse fly Ornithoica exilis (Diptera: Hippoboscidae) was collected from the Okinawa Rail Gallirallus okinawae (Gruiformes: Rallidae) in Okinawa Island, Japan. The present finding represents the first record of O. exilis from G. okinawae and from Okinawa Island.
The relative abundance of Tree Sparrow Passer montanus were compared between 1991-2004 and 2006 in 17 residential areas of Hokkaido. Average numbers (±SD) of birds counted in a transect 2 km long and 50 m wide decreased significantly from 24.6±7.5 in 1991-2004 to 14.5±8.1 in 2006. Relative abundance increased in two study areas, remained unchanged in one area and decreased in 14 areas. Change rates (CR, Number of birds counted in 2006/number of birds counted in 1991-2004) exceeded 1.0 in two areas located in mountainous localities, but were 0.71-1.00 in south-western and eastern parts and less than 0.71 in central parts.
We collected data to see which bird taxa possess unique feather structures, namely the after-shaft and tegmen, as a basis for bird feather identification. Using the collection of the Yamashina Institute for Ornithology, we examined 19 orders, 75 families and 529 species for tegmen feathers, and 18 orders, 44 families and 334 species of non-passerines and six families of passerines for after-shaft feathers. We also examined the authors' personal collection of passerines feathers for after-shaft feathers. After-shafts were present in 15 orders, 35 families and 246 species of non-passerines and 29 families of passerines, and tegmen was present in six orders, nine families and 86 species.
Over a 2-day period, 30-70 Grosbeaks Eophona personata were observed feeding on acorns of several fagaceous species (Quercus glauca, Castanopsis cuspidate and its variation C. cuspidate var. sieboldi) in the understory of evergreen broadleaved forest at Funaokayama Hill, Kyoto City. Grosbeaks cracked the cupula and pericarps of acorns with their bills, and fed only on the embryos and cotyledons inside. This feeding behavior on synzoochorous seeds is very similar to that observed when feeding on anemochorous and endozoochorous seeds.