著者

小澤 良之 門崎 允昭

出版者

森林野生動物研究会

雑誌

森林野生動物研究会誌 (ISSN:09168265)

巻号頁・発行日

vol.22, pp.29-42, 1996 (Released:2017-10-03)

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A survey of the seasonal movement of the population of five species of ticks lxodidae collected from both wild brown bears Ursus arctos and their habitat yeilded the following results The smallest population of ticks except winter in both areas (on both the bears and in their habitat) was found to be in August due to dormancy under high temperatures. This was in common with all the five species. Ixodes ovatus population composed of only adults in both areas changed synchronously. Haemaphysalis megaspinosa population in both areas showed a lag of one month, because of the low prevalence of nymphs on the bears. However, there was found on abundent occurrence of nymphs and larvae in the bears habitat. The other three species (H. japonica, H. flava, I. persulcatus) in both areas changed irregularly because of the differences of developmental stages of ticks which compose each population and because of the prevalence of them to bears, respectiverly.

著者

門崎 允昭 河原 淳 小澤 良之

出版者

森林野生動物研究会

雑誌

森林野生動物研究会誌 (ISSN:09168265)

巻号頁・発行日

vol.21, pp.23-29, 1995 (Released:2017-10-03)

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The authors investigated five injury incidents and one death incident of humans due to attacks by brown bears (Ursus arctos)during hibernation , occurring in Hokkaido Japan during the 26 years from 1970 through to 1995. Details and characteristics of these bear attack incidents and countermeasures to prevent attacks and injury are described within. The reason bears attack while they are hibernating is to protect their den from possible human intrusion. If they scene a possible threat close to their den they will leave their den to drive off the perceived threat. A hibernation den is a tunnal cave dug by bears in a mountain slope. Bears in Hokkaido usually start hibernating from late November to late December and finish hibernating from late March to early May. It has been observed that in general dens with a larger than average entrance have been a feature in relation to attacks on humans. In the one reported case of a human death due to a bear attack in Hokkaido, occurred in early December very early in the bears hibernation. The bear stood up and attacked with its hand claws. All other reported attacks did not lead to death. These attacks all occurred after late February. This is past the half way point of the bears hibernation. The bears had used up so much energy in keeping warm during winter the bears therefore did not have enough energy to stand up and attack. They attacked their human victims only with their teeth. Therefore it appears in order to minimize injury from bear attacks. It is better to start work in bears hibernating areas after late February, which is past the half way term point of hibernation. Bears usually don't have enough energy to stand up and attack past the half way point of their hibernation. Standard safety measures to help prevent bear attacks on humans, people shoud carry a sound-making instrument, such as a whistle or a bell, and a hatchet(a big knife) for self-protection when entering an area presumed to be a bears habitat. While walking, people should blow or rattle the sound-making instrument, or raise their voices in order to avoid encountering bears unexpectedly. Because bears dislike hibernating in a place where the environment has been artificially changed, minor modifications to the environment are effective in preventing bears from making dens. Bears lurking obstinately in their den should not be killed. People can safely work around a bear's den if they remain 50 to 100 m away from it. Bears often use several different dens. Therefore, bears escaping from a den due to the intrusion of humans usually enter another den, and it is not necessary to chase and kill them. When encountering a bear people should never run to escape or feign death as the bear is sure to attack. The best actions are to stand, be confident and shout at the bear in a loud voice. Such actions are often successful and the bear will leave. If a bear should actually attack the best response is to deliver a blow of a hatchet on any part of the bears body. This will increase the chance of survival.