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 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.
カツオドリ Sula leucogaster に比してアオアシカツオドリ S. nebouxii の剥皮体は胸筋が円筒状で肩の張りもない点で異なる。これは後者が前者より高空から深海突入する突入度の違いを反映している。アオアシカツオドリは全く水しぶきをあげずに突入し，カツオドリは多量の白泡を立てる。また，トビウオを空中捕捉する。最も熱帯性のアカアシカツオドリ S. sula は突入体型の度が低い。カツオドリ類はその突入とその前の空中バランス浮揚に関連して大胸筋主部の下に筋肉の盛り上がりのある点が特徴である。アオアシカツオドリは胸筋長/腹長比が1.5でカツオドリの0.9より長いことも深海突入に適応して翼力の強化を示す（強い翼搏には長い胸筋が必要）。胸筋全量 117.2 g, 脚筋量 51.0 g であった。肩部に未記載と思われる三筋，m. biceps subaccessorius（下副二頭膊筋），m. deltoideus major inferior（下大三角筋）と m. deltoideus medius（中三角筋）を認め命名した。
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.