We have analyzed 114 meetings between brown bears (Ursus arctos) and personnel in bear research projects in Sweden and Norway, reviewed the Scandinavian literature, 1750-1962, regarding people injured and killed by bears, and analyzed instances of human injuries relating to bear attacks during the more recent period, 1976-1995. The last time people were killed by bears was in 1902 in Sweden and in 1906 in Norway. However, most meetings between bears and humans result in the bear leaving. We observed no direct attacks, but bluff charges occurred in 4% of the meetings. Blowing and growling were apparently warning behaviors associated with the presence of cubs or carcasses. Seven people have been injured in Scandinavia in the past 20 years; 6 were hunters, and in five cases the bear was wounded or possible wounded. We conclude that the most dangerous situation is when a bear is wounded. In addition, we identified several situations that contributed to increased levels of aggressiveness among bears. They are, in decreasing importance : the presence of cubs, proximity to a carcass, proximity to a den, and the presence of a dog. Our results showed that the Scandinavian brown bear is not particularly dangerous. A relatively high proportion of wounded bears may have contributed to the apparently higher levels of fatalities in the last century.

抄録全体を表示

The reproductive tracts of 29 female Steller sea lions Eumetopias jubatus collected in the Nemuro Strait, Hokkaido, Japan, during the winters of 1995 and 1996, were examined to estimate their reproductive histories and status. After sectioning ovaries at intervale of 250μm thickness, a light microscope was used to examine 23 of the 57 ovaries for small retrograde corpora lutea (RCLs). None of the RCLs that were more than three years old were found. The regression process of an RCL is presumed to occur rapidly because of the pressure exerted by a large corpus luteum of pregnancy (PCL) formed during the subsequent pregnancy. No more than three placental scars were found in any one female, probably because the scars disappeared during placentation during subsequent pregnancies. Thus, estimations of the reproductive histories of Steller sea lions were not possible beyond three years. Females became sexually mature from four to seven years of age, which was one year later than in previous studies (Perlov 1971). Among those sampled during January and February, the pregnancy rate for females that had ovulated was 88.5% (23/26).

抄録全体を表示

One of the greatest public concerns about wolf recovery in Japan is whether or not there is sufficient space to provide suitable wolf habitat. To address this concern, we quantitatively compared the distribution patterns of human residences and facilities between Bieszczady National Park, a park in Poland inhabited by wolves, and various natural areas in Japan. We selected twenty-six sites (8 national parks (NP), 12 quasi-national parks (qNP), and 6 other wilderness areas) in Japan, based on geographic features and on the distribution of prey (sika deer Cervus nippon). We superimposed grid cells over maps of Bieszczady (1 : 75,000) and the selected locations in Japan (1 : 50,000) and counted the number of houses or building symbols in each cell. Our analyses indicated that, of the twenty-six sites, ten showed distribution patterns similar to, or simpler than, Bieszczady for three crucial criteria: residential rate (RR), Green's index (GI), and fractal dimension (D_f). Ten other sites had moderately higher RR values than Bieszczady, but had similar GI and D_f patterns, and six areas were deemed different from Bieszczady in terms of these three criteria. We suggest that, with respect to human residential patterns, wolf restoration in Japan can be recommended for the following ten areas: Shiretoko NP, Akan NP, Hidaka Mountains/Erimo qNP, Mount Daisetsu NP, Nikko NP, Chichibu/Tama NP, South Alps NP, Yoshino/Kumano NP, Koya/Ryujin qNP, and the Kyushu Central Mountains qNP.

抄録全体を表示

Changes in the population dynamics of the Japanese serow Capricornis crispus and the sika deer Cervus nippon were studied in the Ashio Mountains of Nikko National Park, Tochigi Prefecture, Japan, from March 1982 to December 1995. Although the geographical distributions of the two species overlap in many areas of Japan, wherever the snow is not deep, Japanese serow and sika deer are usually found living allopatrically. In Ashio, however, they occurred sympatrically, but their populations have changed drastically and they have segregated during the 1980s and 1990s. I propose two factors that may contribute to their shift from sympatry towards an allopatric existence. The primary contributing factor may be the overlap in the food habits of the two species. Japanese serow were found to feed on the leaves of deciduous trees and herbaceous shrubs during the summer, while in winter they feed mainly on the needles of coniferous trees. In contrast, sika deer were found to feed mainly on graminoid species year round. Only in severe winters did the deer extend their diet to include the needles of coniferous trees, and the twigs and bark of deciduous trees. During such winters their diet then overlaps that of the serow, and this overlap may result in a rapid depletion of limited food supplies. The deer, with their more flexible dietary habits may be better able to tolerate such poor foraging conditions, whereas the serow may suffer from an unbalanced diet and face a deficiency of food thus forcing them to move away from areas where deer are present. A secondary cause may be the increased interactions between the species. Serow are territorial and essentially solitary, and so are presumed to be sensitive to both intra-and inter-specific crowding, whereas sika deer are not territorial, occur in herds and are usually very tolerant of other animals. In order to avoid encounters with sika deer, the sensitive serow may emigrate from areas with high deer population densities. This competitive/avoidance relationship between the Japanese serow and sika deer may help to explain why the two species generally occur allopatrically in Japan.

抄録全体を表示

Seven large carnivores and omnivores (the tiger (Panthera tigris), clouded leopard (Neofelis nebulosa), leopard (P. pardus), Asiatic golden cat (F. temminckii), Asiatic black bear (Selenarctos thibetanus), Malayan sun bear (Helarctos malayanus), and dhole (Cuon alpinus)), are known still to occur in Vietnam. Unfortunately, all of them are classified as "endangered" or "vulnerable" in the Red Data Book of Vietnam (Ministry of Science Technology and Environment 1992). Their poor status is the result of extreme population declines caused by illegal hunting for food and medicine, by deforestation, and by hunting for the illegal wildlife trade. These anti-conservation activities are rooted in the countries poor economic situation, particularly among local rural communities. An increase in national welfare, resulting from the introduction of modern, and more technical agricultural methods, along with improved public nature conservation education, and strict enforcement of the law, may be required before these problems can be resolved. Research on Vietnam's large carnivores, and action plans for their conservation, is urgently needed.

抄録全体を表示

Cooperative surveys by Russian and Japanese scientists were conducted on the status of Steller sea lion Eumetopias jubatus in the Kuril Islands in 1995, and American scientists joined in this project in 1996. In 1995, a total of 1,541 pups and 2,652 non-pups were counted at four of the five surveyed rookeries, Antsiferova Island, Raykoke Island, Lovushki Rocks, Srednego Island, and Chernyye Brat'ya Island, and in 1996 a total of 954 pups and 1,730 non-pups were counted at three rookeries. A total of 701 pups were tagged and branded on seven occasions at five rookeries. Pup mortality was estimated to be between 2.6% and 7.1%, based on the counts of live and dead pups on the days of tagging and branding. On Raykoke Island, the branded pups may be different in mortality from non-branded ones. Seven debris-entangled sea lions were found in 1995, but no entangled sea lions were found in 1996. One tagged or branded male and 11 females were re-sighted on Srednego Island, 29 females on Raykoke Island, 4 females on Antsiferova Island, one male each on Shiashkotan and Onekotan Islands. Multiple observations of the marked sea lions suggest that they travel widely in the Okhotsk Sea, the Japan Sea, and the North Pacific.

抄録全体を表示