The subspecies fujiyamae of Northern Goshawk Accipiter gentilis breeds in Japan, Sakhalin, and Southern Kurile Islands as an endemic subspecies (OSJ 2000). This paper shows the measurements from 64 individuals of A. g. fujiyamae caught in central Saitama and southeastern Tochigi Prefectures, Honshu, along with the identification criteria of sex and age based upon measurements (Table 1), plumage features (Fig.1), and iris colour (Table 2). Adult males were significantly smaller than adult females for all measurements (Table 1). Tails of juveniles were significantly longer than adult tails for males (t-test, t=2.238, df=26, P<0.05) and probably also for females (Table 1). We could distinguish the age as juvenile, first winter, and adult plumages based on the plumages combined with iris colour (Fig.1). A few juvenile feathers of upper and under wing-coverts remained in first winter plumage until about two years old, which was the bird's third year. Measurements from live birds tended to be larger than the data reported in the literature, which were mostly taken from specimens. The difference was as large as 10 mm in the case of tarsus length. The iris was pale yellow (sulfur yellow) in juvenile plumage and tended to acquire an orange tinge as the bird aged, mainly spectrum yellow or orange yellow in first winter plumage, and orange yellow or orange in adult plumage after in the second winter plumage. We show for the first time that the iris may turn red for old males of Japanese Northern Goshawks A. g. fujiyamae (Table 2 and Fig. 1).
The distribution and population size of crows inhabiting the alpine zone (above 2,400 m asl), central Honshu, were studied on the basis of published literature, a 2005 questionnaire survey and interviews of the owners of mountain huts. Crows were present at 45 of the 62 high mountains surveyed. The distribution was increased because the crows occurred at 11 mountains before the 1970s. There were 1-4 individuals at each mountain and they were usually observed from May to October when the mountain huts opened. We estimated a total of 156 individuals at the 45 high mountains: most were Jungle Crows (Corvus macrorhynchos). The crows scavenged the food scraps dumped by mountain climbers. Moreover, at some mountains they ate the eggs and chicks of the Rock Ptarmigan (Lagopus mutus), the Alpine Accentor (Prunella collaris), and the House Martin (Delichon urbica). Attention should be paid to the future distribution and diet of crows inhabiting the alpine zone.
High concentrations of insecticide “fenthion” were detected in the muscles, livers and stomach contents of several dead Japanese Cranes (Grus japonensis) found at Memambetsu Town, northeastern Hokkaido. A follow-up survey in another five dead cranes revealed high fenthion concentrations in the pectoral muscle, liver and stomach contents of two cranes found at Shibecha Town and Tsurui Village in eastern Hokkaido. The concentrations of fenthion were 0.14 mg/kg-wet in muscle, 0.13 mg/kg-wet each in liver and 7.9 mg in stomach contents, respectively.