We studied the foraging behavior of the Japanese White-eye in three species of mangroves, Bruguiera gymnorrhiza, Kandelia candel and Rhiziphora mucronata, in July-August and October at sub-tropical Iriomote Island, southern Japan. During the study period the Japanese White-eye appeared to utilize only one species as a nectar source; B. gymnorrhiza, which has flower characteristics specialized for pollination by birds.
The incidence of return to their breeding grounds by the Reed Bunting Emberiza schoeniclus was investigated in western Hokkaido during six seasons (1997-2002). During this survey period, a total of 1, 568 individuals (508 adults, 411 juveniles and 639 nestlings) were given leg bands in the breeding season (Apr. 1-Sept. 10). A total of 150 birds were recaptured after one year, indicating the estimated minimum return rate in the next year as being 9.57%. The return rate dropped exponentially over subsequent years, falling to 1% or less 4-5 years later. The rate of return after one year in adult birds, juveniles and nestlings was 14.37%, 10.22% and 5.48%, respectively. There was no difference in the rate of return between adult males and females. It is conceivable that the true return rate may be higher than our estimates, because not all the returned individuals were necessarily captured by the end of this survey period.
In 2002, young Japanese Cranes Grus japonensis held captive in a facility located next to the winter feeding station in Hokkaido showed symptoms of Disseminated Visceral Coccidiosis (DVC). Screening revealed the presence of oocysts of the coccidia Eimeria gruis and Eimeria reichenowi in the feces of wild cranes, the first record of this infection in wild cranes in Hokkaido. Coccidian oocysts were distributed throughout the entire habitat area, though no serious effects have yet occurred. Given the high density of cranes at winter feeding stations and the decrease of the breeding habitat in Japan, the potential danger posed to the natural crane population by eimerian coccidiosis should be an important concern in the wildlife management practices for this species.
We observed that two species of crows reused nest materials. Given the conventional knowledge that crows avoid breeding in their old nests, this behavior is both novel and surprizing. Pairs removed materials from their completed nests and carried them to other sites, and there used the old materials in the construction of new nests. It is unknown whether any eggs were laid in the original nest or whether the nest was abandoned prematurely. One pair of Carrion Crows reused twigs, and two pairs of Jungle Crows reused wire-hangers and twigs for the outer shell of their nests. However, inner linings were newly obtained in all cases. These observations suggest that the reuse of nest materials by crows may be more common than was hitherto believed.