The geographical distribution, density and population composition of sika deer Cervus nippon were studied in Nikko National Park, central Honshu, Japan. Deer density, distribution, age-sex structure, and group size were investigated along five sampling routes ranging from a traditional wintering area at Omote Nikko, to the distributional limit at Oku Nikko, from April to December 1995. Dry standing biomass, culm and leaflengths of Sasa nipponica, the major food species of sika deer, were measured by harvesting a total of 80 1 × 1 m plots along the same five sampling routes. The Nikko sika deer population began to irrupt, extending its distribution, after a mass die-off during winter 1984. The availability of food resources for sika deer has improved in the region due to the decrease in snow accumulation as a result of climatic warming, this has led to an increase in the environmental carrying capacity during winter. In the traditional wintering area, S. nipponica was dwarfed under the high grazing pressure of sika deer, as a result its standing biomass decreased, and deer density was lower. More females and calves occupied the new and traditional wintering grounds than in the frontier area at Oku Nikko. In these wintering grounds, males occurred at very low densities, except for during the rutting season. During the non-rutting season, males inhabited the frontier area of the summer range and/or the outer area of the wintering grounds, and sex segregation was observed in these areas. From the traditional wintering ground to the frontier area, the ratio of juveniles to adult females increased, while the opposite was true for the calf to adult female ratio. The establishment of a new wintering area in a previously snowy area can be expected to provide a base from which sika deer will be able to establish further wintering grounds in future. As global warming continues, the Nikko sika deer population may further extend and enlarge its range into the surrounding areas.
Using infrared sensing and visual observations, ten helicopter censuses of the sika deer Cervus nippon and the Japanese serow Capricornis crispus populations in the southern part of Nikko National Park were conducted between December 1995 and February 1999. The data collected were used to estimate densities and distribution of the ungulates and to analyze their habitat selection with the help of GIS. The density of sika deer ranged between 11.6 and 33.1/km2 in Omote Nikko, Ashio, and Tone, while in Oku Nikko it fluctuated between 1.9 and 11.3/km2. The animals preferred mid elevations, gentle slopes and areas distant from roads. In winter (February and March) they strongly avoided northern and western exposures, whereas in late autumn (November and December) all aspect classes were used in accordance to their availability. The habitat selection by sika deer in Nikko National Park appeared to be affected primarily by human activity in late autumn and by snow depth in winter. Serows were observed only sporadically and their density did not exceed 1.0/km2. They selected steep slopes and areas close to roads, seemingly in order to avoid sika deer. Comparison of the present sika deer density and distribution with earlier data suggests that their population has already reached carrying capacity in the traditional wintering range and its further increase will be realized by expanding the winter distribution range if global warming continues and the current hunting policy is not changed. In contrast to the situation amongst the sika deer, the Japanese serow population in Nikko National Park is undergoing a serious decline due to competition with sika deer. The utility of aerial surveys as a method for estimating wildlife populations in Japan is also discussed.
Detectable movement rates and road crossing rates of seven radio-collared brown bears Ursus arctos yesoensis were compared with traffic volume indices (TVI) in Shiretoko National Park during 1994, 1995 and 1996 in order to evaluate the impacts of vehicle traffic on bear road crossings. All bears in our study moved most often during daytime, although they showed some individual variation. Road crossing rates of bears were highest in the morning, daytime and evening periods. Brown bears crossed roads during the daytime, when TVI was the highest, as well as during the morning and evening when TVI was low. Furthermore, when vehicle traffic volumes peaked, the mean pooled TVI values during the time periods when road crossings were detected did not differ from the values when no road crossings were detected. Road crossings by brown bears were not inhibited by vehicle traffic in Shiretoko National Park.
Asiatic black bear (Ursus thibetanus) depredation levels remain high in Japan even though over 1,000 nuisance bears are killed annually, and an additional 1,000 bears are killed during the hunting season. Nuisance activity includes damages to trees, crops, orchards, apiaries, fish farms, and other property. Landowners experiencing bear damages request hunter assistance. Hunters then set cage traps to catch and kill nuisance bears, and legally sell the parts, especially the gall bladders, of the bears they killed. We promoted non-lethal methods to reduce Asiatic black bear depredation in Nagano Prefecture from 1995 to 2000. Hunters were the most reluctant to adopt non-lethal methods to reduce depredation; landowners were somewhat reluctant; and municipal officials were the least reluctant. Hunter financial and emotional rewards for killing bears were large. Landowners were not actively involved in the protection of their property because they lacked know-how and resources, and because hunters offered an easy alternative. Reducing long term depredation may require the prefectural government to: (1) lead an aggressive and sustained campaign to teach landowners how to avoid conflicts with bears and to reinforce the fact that the systematic killing of nuisance bears has failed to reduce long term depredation in the past; (2) encourage and finance widespread use of preventive methods such as the removal of bear attractants, the planting of crops that are not attractive to bears in areas at risk, electric fences, and the protection and restoration of broadleaf forests rich in bear foods; and (3) change or remove the financial incentives linking the killing of bears to the protection of property. Furthermore, a national bear gall bladder tagging system would allow the monitoring of the legal national trade in bear parts and would help monitor annual bear kills.
Thirty-nine troops of Sichuan snub-nosed monkey (Rhinopithecus roxellana) with 3,800-4,000 individuals were estimated to inhabit Qinling Mountains, China. Among the various human impacts on this species, deforestation as a result of the spread of agriculture, commercial logging and fuel wood collection, and increased poaching as the human population of the region increases, are all major problems. Under the current conditions, the future of the species is insecure. The current status of the species is outlined, as are the problems that they face, and countermeasures for their conservation are proposed. These countermeasures should include law enforcement, public education, improved forestry policy, the establishment of nature reserves, control of the human population, research, management of buffer zones, and ecotourism.
The government of Nagano Prefecture, central Japan, financed research in 1992 and 1993 to document Asiatic black bear (Ursus thibetanus) ecology, density, and population parameters throughout the prefecture. The prefectural government published the methods and results of this research in 1994, followed by an Asiatic black bear management proposal in 1995. However, most of the research methods used were not adapted to the credible documentation of bear ecology, density, and population parameters. Consequently, most of the results obtained and the management proposal are of dubious value. In Nagano Prefecture, municipal governments are entrusted with the management of the bears within their jurisdictions, limiting input from the prefectural government. Nevertheless, the Nagano prefectural government should not finance flawed bear research nor propose a bear management plan based on such research. A responsible bear management plan should be based on scientifically obtained data. We use existing literature to point out flaws in the research methodology used in the prefecture and to suggest alternative methods. We wish this commentary to be constructive and hope it will encourage sounder bear research in the prefecture and throughout Japan in the future.
This paper lists 168 marine algae, 16 of which belong to Chlorophyta, 39 to Phaeophyta, 113 to Rhodophyta, and one species of sea grass from Unosaki of Oga Peninsula. Twenty-eight species are newly recorded from the Japan Sea coast of northern Honshu.