The location of winter roosts and foraging areas of the Grey Starling Sturnus cineraceus were studied in Kanto Plain, central Honshu, Japan from October 2002 to February 2003, and compared with earlier studies in the same area by Kuroda (1955, 1956, 1962). The present study located 37 winter roosts and categorized them into two types: "large roosts", occupied by 4, 000 or more individuals and "small roosts", occupied by 1, 000 or fewer individuals. Individuals departing from large roosts flew to more distant foraging grounds than those departing from small roosts. For the Shinhama roost, categorized as a large roost, the number of assembling individuals and their foraging area were almost the same as those observed by Kuroda between 1953 and 1962. However, a comparison between the results of the present study for the Saitama roost, categorized as a large roost, and those of Kuroda, revealed that the number of assembling individuals had decreased considerably over the four decades interim period, and that their foraging areas had also changed. Recent studies of the Grey Starling have documented the existence of fewer roost sites with larger numbers of assembling individuals in summer, and of numerous interspersed roosts with smaller numbers of individuals in winter. In the present study, however, both large roosts and small roosts were present in the study area in winter.
The number of eggs in nests of the Black-winged Stilt Himantopus himantopus himantopus in areas in Tokyo Metropolis and Chiba Prefecture, around the Tokyo Bay was investigated. The mean ± SE number of eggs in nests was 3.50±0.06 (n=384, range 1-10). Instances of five or more eggs in a nest were suggested to have been produced by two or three females. The mean ± SE of clutch size by monogamous pairs was 3.36±0.05 (n=362, range 1-4).
Body weights and linear measurements of Hazel Grouse Bonasa bonasia are presented based on birds shot in 1995 and 1996 in Hokkaido. Janan. During the period from July to January of the following year the average body weights (±SD) of males ranged from 369.1±29.1g (July to September) to 415.4±15.5g (December and January), and that of females from 344.3±27.6g (July to Sepember) to 418.5±3.5g (December and January), showing a significant increase in winter. The average flattened wing, tail, tarsus and culmen lengths for males were 170.2±3.9mm, 124.7±5.9mm, 36.5±1.2mm and 13.4±0.9mm, respectively. The corresponding values for females were 169.9± 2.3mm, 117.6±2.2mm, 36.7±1.0mm and 13.3±1.2mm, respectively. There was no significant difference in wing, tarsus and culmen lengths between the sexes, but the average tail length of males was significantly longer than that of females.
Possible seed dispersal agents of a pioneer tree Mallotus japonicus were observed on Iriomote Island in the summer of 2003. When the fruit is ripe, the shell opens and exposes a clump of blackish lipid-rich seeds. The seeds attract many species of birds. Observation for four days (34hrs) at the tree stands revealed four species of birds, the Jungle Crow Corvus macrorhynchos osai, the Japanese White-eye Zosterops japonicus loochooensis, the Brown-eared Bulbul Hypsipetes amaurotis stejnegeri, and the Emerald Dove Chalcophaps indica yamashinai, to visit and eat the seeds. These endemic sub-species of birds are regarded as important seed dispersers of this pioneer tree.
It is important to understand the foraging ecology of the Hodgson's Hawk-eagle Spizaetus nipalensis in order to determine the environmental conditions that they depend on for their survival and reproduction. However to date, no detailed analysis of predation has been reported for this species. We lured wild Hodgson's Hawk-eagles using live chicken Gallus gallus var. domesticus, and recorded two series of predation from the moment of attack to the end of feeding on 9th and 16th September 2004. The eagles took 182 and 142 minutes from the attack to the end of feeding, respectively. Although we were unable to identify individuals, the manner of predation was different between the sequences and the parts eaten. The eagle recorded on 9th September plucked out the feathers intensively before feeding, while the eagle recorded on 16th divided plucking into several times, not only before but also during feeding. The eagle recorded on 9th fed on the flesh at the rear part of the body and intestines, while the eagle recorded on 16th fed on the flesh at the front part of the body. As points in common between them, the eagles both swooped down to the chicken from inside the forest. The chicken seemed not to be aware of the eagle until 1-2 seconds before the moment of impact. The eagle plucked out the feathers and tore off the flesh with a repetitive front-back motion. The eagle did not seem to try carrying the chicken carcass away after feeding.
A single Daurian Jackdaw (Corvus dauuricus) was observed on 6 February and 16 March 2003, at farmland in Shiranuka, Hokkaido. The bird has pied plumage, a dark iris, and was half the size of a Carrion Crow (C. corone). This is a first observation record of this species in Kushiro Subprefecture, Hokkaido.
Cutting of the eggshell of an extinct ratite, the Elephant Bird (Aepyornis), was undertaken to obtain the egg contents previously observed by Computed Tomography, for the aim of extracting DNA from the egg contents for future analytical study. Furthermore, in addition to obtaining uncontaminated samples from the eggshell, it was also required to establish an accurate cutting method that permitted egg reconstruction. We here describe in detail a technique of use in cutting invaluable half-fossilized eggshells, based upon a method using hand-worked bow saws.