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Volume 42 (2002)
- Issue 2 Pages 113-
- Issue 1 Pages 1-
Volume 42, Issue 2
Displaying 1-8 of 8 articles from this issue
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Original Article
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Hiromasa Igota, Koichi Waseda, Mayumi Sakuragi, Hiroyuki Uno, Koichi K ...2002 Volume 42 Issue 2 Pages 113-121
Published: 2002
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSWe evaluated the ability of GPS collars in eastern Hokkaido during August and September, 2000. We placed the collars in a range of three types of environment (i.e., Open-flat, Covered-flat, and Covered-steep) and compared the GPS location. Rate of success in getting positions were 97%, 45%, and 57%, respectively, in the collar made by Televilt, and 100%, 97%, and 94% in Lotek. Vegetation cover decreased the success of location attempts. Rate of 3-dimensional positions were 55%, 36%, and 18% in Televilt, 97%, 47%, and 66% in Lotek, affected by vegetation cover and topography. Positional error (mean±SD) were 48±32m in Televilt, and 35±30m, Lotek. There were no differences among the three environment. We placed a GPS collar on a free-ranging Hokkaido sika deer (Cervus nippon yesoensis) in Shiranuka Hills, Hokkaido, in March, 1999 and its recorded 39locations, 5% of attempt, after 1year. Animal-tracking by GPS is developing now and expected to be refined in its rate of success in locating positions and occurrences in positional error.View full abstractDownload PDF (417K) -
Oi Toru, Tatsuya Otani, Shingo Miura, Tunenori Tujimoto, Chihiro Fujiw ...2002 Volume 42 Issue 2 Pages 123-128
Published: 2002
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe Argos system is a commercial satellite-based system for locating mobile transmitters and collecting data from the transmitters. Users of the system can receive the positions of the transmitters on the Internet. The applicability of the Argos system to track large wild mammals such as Asiatic black bears in Japan was examined. The system was capable of determining the location of the transmitter (Telonics, ST-14PTT) to within 225m to 9500m. Two wild bears were tracked with the Argos system. The position data of one animal was obtained 2.8times per day and the position data of the other was obtained 0.70times per day. Among these data, highly accurate positions of the two bears with standard deviations of estimated errors less than 350m were obtained 0.50 and 0.10times per day, respectively. A problem with the use of this system in mountainous habitat is that it is unable to estimate altitude. However, a new model that includes a GPS unit can more accurately estimate positions including altitude and is expected to be more practical.View full abstractDownload PDF (89K) -
Hiroyuki Uno, Katsumi Tamada, Hirofumi Hirakawa, Rika Akamatsu2002 Volume 42 Issue 2 Pages 129-137
Published: 2002
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSWe evaluated the ability of GPS collars in eastern Hokkaido during August and September, 2000. We placed the collars in a range of three types of environment (i.e., Open-flat, Covered-flat, and Covered-steep) and compared the GPS location. Rate of success in getting positions were 97%, 45%, and 57%, respectively, in the collar made by Televilt, and 100%, 97%, and 94% in Lotek. Vegetation cover decreased the success of location attempts. Rate of 3-dimensional positions were 55%, 36%, and 18% in Televilt, 97%, 47%, and 66% in Lotek, affected by vegetation cover and topography. Positional error (mean±SD) were 48±32m in Televilt, and 35±30m, Lotek. There were no differences among the three environment. We placed a GPS collar on a free-ranging Hokkaido sika deer (Cervus nippon yesoensis) in Shiranuka Hills, Hokkaido, in March, 1999 and its recorded 39locations, 5% of attempt, after 1year. Animal-tracking by GPS is developing now and expected to be refined in its rate of success in locating positions and occurrences in positional error.View full abstractDownload PDF (236K) -
Hiroshi Dewa2002 Volume 42 Issue 2 Pages 139-151
Published: 2002
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDistribution, composition of the species of small rodents and utilization of the forest island habitat (isolated patches of forest) were surveyed in the farmland area near Asahikawa, Hokkaido, Japan. Twelve trapping stations using the capture-recapture method were established in the forest area (Byobu-yama), three forest islands (Oya-yama: 5.1ha, Ko-yama: 4.1ha and Kubo-yama: 0.3ha) and farmlands (rice fields, sugar beet fields, wheat fields, grassy strips along railroads and farm roads, barns and green houses). Dominance and relative density of eight species of small rodents were determined at each station every month from June 1986 to November 1988 except during the snow season (from December to April). Three species: Clethrionomys rufocanus bedfordiae, Apodemus argenteus and A. speciosus ainu were confirmed as the principal constituents of the fauna in the forest area and the forest island. In the farmland, four species—C. r. bedfordiae, A. peninsulae, Rattus norvegicus and Mus musculus—were confirmed as the principal constituents of the fauna here. Three types of habitat utilization by small rodents were recognized as follows: a) C. r. bedfordiae used both the forest island and the farmland as main habitats, and migrations between the forest island and the farmland were observed all year round. b) A. argenteus and A. s. ainu utilized the forest island as a habitat and the farmland were utilized as a dispersal corridor in the autumn. If habitat area in the island was small, they would use the forest islands as a temporary winter habitat. c) A. peninsulae, R. norvegicus and M. musculus utilized the farmland as its main habitat and also invaded the forest island from September to November to utilize it as a temporary habitat.View full abstractDownload PDF (582K) -
Keishi Sekiguchi, Go Ogura, Takeshi Sasaki, Yasuhiko Nagayama, Kohiyun ...2002 Volume 42 Issue 2 Pages 153-160
Published: 2002
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe seasonal diet of Japanese weasel (Mustela itatsi), which had been introduced to the island in 1957 and 1958, was studied by feces analysis during the summer and autumn to evaluate their effect on the endemic species of Zamami Island. Japanese weasels ate a wide variety of prey, consisting mainly of insects. The proportions of prey animals based on their occurrence and dry weights indicated that insects were the most common foods in both seasons. Reptiles and mammals were the next most common prey in summer and autumn, respectively, according to the proportion of dry weight. Considered with the seasonal change of each prey animal, only reptiles showed a significant reduction in proportions of dry weight. There have been many concerns about the influence of introduced animals on endemic species, especially in the case of introduction to a small island. In the present study, it was suggested that the population of endemic reptiles on Zamami Island was particularly susceptible to predation by the Japanese weasel. As well, it is predicted that the Japanese weasel would affect the populations of the other animals since the Japanese weasel is the most dominant predator on this island.View full abstractDownload PDF (219K)
Short Communication
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Shuhei Hayaishi, Yoshi Kawamoto2002 Volume 42 Issue 2 Pages 161-166
Published: 2002
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSWe studied the mitochondrial DNA (mtDNA) haplotypes of Japanese macaques on Yakushima Island, Kyushu, Japan, using fecal DNA samples. The age-class of the macaques was estimated by measuring the size of feces from macaques from Arashiyama, Kyoto, and Yakushima. We observed at least four different mtDNA haplotypes from Yakushima: Yakushima 1 (n=34), Yakushima 2 (n=2), Yakushima 3 (n=2), and Yakushima 4 (n=1) (DDBJ; Accession No.: AB093529-32). The estimated size of the feces of juvenile macaques was <18mm and that of adolescent and adult macaques was >25mm at both Arashiyama and Yakushima. The results imply that analysis of mtDNA haplotypes in combination with age-class estimation through fecal measurements is a useful tool for studying matrilineal group structure and male dispersal patterns in the Yakushima macaques.View full abstractDownload PDF (319K) -
Kazue Noguchi2002 Volume 42 Issue 2 Pages 167-170
Published: 2002
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSSeasonal changes of the testis were studied in 30 specimens of the male raccoon dogs, Nyctereutes procyonoides, which were killed by a traffic accident in Kagawa Prefecture during 1996-2001. Ages of the animals were determined by cementum layer method. The length and the width of the testis were significantly correlated with the weight plotted in logarithm. The testis weight grew from July to October within one year old. The testis weight then became heaviest from January to April, when the epididymis contained sperms. And the testis weight decreased in May. Therefore, the male raccoon dogs attained its sexual maturity within one year old, and the maturation period was estimated from January to April. The maximum period of the testis weight accorded with the previous reports of the behavioral changes and coition observed in captivity.View full abstractDownload PDF (124K)
Book Review
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2002 Volume 42 Issue 2 Pages 171-174
Published: 2002
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (44K)
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