Iwate prefecture is the largest area in Honshu Island, and much wildlife inhabits, this area. Asiatic black bears (Ursus thibetanus) inhabit almost all regions of Iwate prefecture; they make up a large part of Japan's black bear population. In the past, Sika deer (Cervus nippon) extensively inhabited the Tohoku region. Due to overexploitation and heavy snow from the Meiji Era to the beginning of the Showa era, their population suffered from a crash, and the distribution of the Sika deer population settled exclusively around the Mt. Goyo area. Japanese serow (Capricornis crispus) also decreased in number from over-hunting, and was declared a National Japanese Treasure as a protected species. However, because of agricultural and forestry damages caused by wildlife has become a social problem since the 1980's, owing to the increase of population size (of at least sika and serow) and/or the enlargement of distribution, the prefecture made the Specified Wildlife Conservation and Management Plans(SWCMP). The several monitoring projects which supply important information for carrying out the SWCMP are continuously conducted every year with the cooperation of many hunters. While continuing these monitoring projects, the prefecture has carried out appropriate wildlife management, but recently several problems have started to occur. First, it is difficult to estimate population size accurately. Secondly, there has been an enlargement of distribution, leading to more "wandering" into human communities. Furthermore, the number of hunters is decreasing remarkably. In order to solve these problems, the development of new monitoring methods, the control of distribution enlargement, and an approach that collaborates with local society to control wildlife damage, is needed.
This study aims to analyze the characteristic points of people's view & attitude towards animals in Japan, and refer to the unsuitable influence caused by these chracteristic points such as the decline of hunting and the obstacle in executing of wildlife management. As the conclusions ,this study has mainly pointed the following proposals, i) we should improve the view & attitude towards animals according to the fundamental conception as is shown by the Basic Guideline on Humane Treatment of Animals established by the Environment Minister ii) we should seek the adequate method of population control, excluding the excessive emotional factor in capturing and killing wild animals, and finally should establish the scientifically and socially suited method of population control.
Body fat mass(FM) of the Japanese black bear (Ursus thibetanus japonicus) was examined by bioelectrical impedance analysis(BIA) using Model Quantum X (RJL systems). Whole-body resistance was measured between forelimbs and hind limbs in the recumbent position. The FM was calculated by the equations for the American black bear. In 5 captive Japanese black bears, from September 2005 to January 2006, changes in FM and body mass(BM) were highly correlated (r=0.89). This study demonstrates that BIA is useful in the measurement of FM in the Japanese black bear, and that an increase in BM in autumn means an accumulation of FM. Seasonal changes in fat ratio(FR) in captive female Japanese black bears indicated lowest (29.3±3.3%) in early September and highest (41.6±3.0%) in December. The total fat accumulation (36.6kg FM) before hibernation corresponded to 252,000kcal and was consumed at 1,900kcal/day during hibernation. In 13 wild bears (in Gifu and Yamanashi Prefecture), FR was 6.9 to 31.7% from June to November 2006. The values in these wild Japanese black bears were low in comparison to those in captive bears. In conclusion, BIA facilitates the gathering of information on the live Japanese black bear's nutritional conditions and estimates their habitat environment through the year.
The Japanese Whale Research Program under Special Permit in the Antarctic(JARPA) and in the Northwest Pacific Ocean (JARPN) has been conducted by the Institute of Cetacean Research(ICR). The lethal component of the JARPA and JARPN was an explosive harpoon used as the primary method of killing whales. In order to improve the method of whale killing, ICR and Kyodo Senpaku made improvements to the explosive harpoon. The newly developed Norwegian grenade and the improved Japanese grenade were compared to the traditional Japanese grenade. Trial firing using cubic target objects and practical experiments were conducted from 2000 to 2004. The new Norwegian grenade and the improved Japanese grenade decreased the time to death(TTD; the time from the first harpoon strike to death of the whale) and increased the instantaneous death rate(IDR) significantly compared to the traditional Japanese grenade. Both the improved Japanese and new Norwegian grenades have common features of low rate of misfire and short explosive distance (the distance from a hit point of the harpoon to point of the grenade explosion), which increased a rate of the explosion of the grenade inside the whale's body. Comparing the two types of grenades, the Norwegian grenade had a higher IDR for smaller whales. It was also easy to handle and load because of its integrated structure. The improved Japanese grenade had the shortest TTD and the lowest rate of misfire. As there is not much difference in actual performance between the two, the lower price of the Japanese grenade may be an important factor in selecting future whaling devices.
Babesia sp. was found in the erythrocytic cytoplasm of 6 crested serpent eagles (Spilornis cheela) in Yaeyama Archipelago, Okinawa, Japan. The examined birds showed 0.1±0.09%(Avg±SE) parasitemia. Considering the morphologic characteristics and morphometrics of haemosporidian parasite, we assumed that they were closely related to B. moshkovskii found in the birds of the family Accipitridae. However, some morphometric differences were observed between the Babesia sp. isolated from the crested serpent eagles and haemosporidian parasite from other host species mentioned previously; thus, further inspection using molecular analysis is required for accurate identification. No haemosporidian parasite-induced pathognomonic clinical signs were observed. This is the first report on Babesia infection in Japanese wild birds and a new host record for an avian piroplasm parasitising crested serpent eagles.
Hepatitis E Virus(HEV) infections have been reported in deer as well as in domestic animals; however, the precise epidemiological information regarding HEV infections in the Shika Deer in Nara Park in Japan remains to be investigated. In this study, we examined the anti-HEV antibodies and HEV-RNA in sera from 173 of female sika deer in the park. The reactivity to HEV antigen in the serum samples were low levels. The detection of HEV-RNA in sera from the deer revealed no positive samples by RT-PCR analysis. In conclusion, we could not able to identify the HEV antibody and HEV-RNA positive individual in the sika deer which inhabited Nara Park. Therefore, the possibility of the HEV infection in the deer of the park would be extremely low.
Here we report on mycobacteriosis in a captive population of an endangered fish species, the Ryukyuayu(Plecoglossus altivelis ryukyuensis), reared at the Okinawa Chura-umi aquarium in Japan. In 2004, some of these fish began to show clinical signs of the disease, such as a spinning motion and/or poor swimming ability, and petechiae on the body surface. The livers of diseased fish exhibited white nodules of various sizes. Apparent swelling of the trunk kidney was also seen in some cases. The most prominent histopathological characteristic was the presence of granulomatous lesions, which comprised a mosaic of macrophage-like cells, in the trunk kidney, spleen, liver, heart, gills and meninges. Numerous colonies of long and slender acid-fast rods were observed within the granulomatous lesions. The bacterial strain isolated from the diseased fish was identified as Mycobacterium marinum.