Uno R.,Keio University |
Kondo M.,Japan Institute for Environmental Sciences |
Yuasa T.,Wildlife Management Office Inc. |
Yamauchi K.,Japan Institute for Environmental Sciences |
And 3 more authors.
Population Ecology | Year: 2012
Non-invasive DNA genotyping using hair samples has become a common method in population surveys of Asiatic black bears (Ursus thibetanus) in Japan; however, the accuracy of the genotyping data has rarely been discussed in empirical studies. Therefore, we conducted a large-scale pilot study to examine genotyping accuracy and sought an efficient way of error-checking hair-trapping data. We collected 2,067 hair samples, successfully determined the genotypes of 1,245 samples, and identified 295 individuals. The genotyping data were further divided into 3 subsets of data according to the number of hairs used for DNA extraction in each sample (1-4, 5-9, and ≥10 hairs), and the error rates of allelic dropout and false alleles were estimated for each subset using a maximum likelihood method. The genotyping error rates in the samples with ≥10 hairs were found to be lower than those in the samples with 1-4 and 5-9 hairs. The presence of erroneous genotypes among the identified individuals was further checked using a post hoc goodness-of-fit test that determined the match between the expected and observed frequencies of individual homozygotes at 0-6 loci. The results indicated the presence of erroneous genotypes, possibly as a result of allelic dropout, in the samples. Therefore, for improved accuracy, it is recommended that samples containing ≥10 hairs should be used for genotyping and a post hoc goodness-of-fit test should be performed to exclude erroneous genotypes before proceeding with downstream analysis such as capture-mark-recapture estimation. © 2012 The Society of Population Ecology and Springer.
Takii A.,Shinshu University |
Izumiyama S.,Shinshu University |
Mochizuki T.,Akatsuki Wildlife Research Office |
Okumura T.,Wildlife Management Office Inc. |
Sato S.,Nagano Prefecture
Mammal Study | Year: 2012
Movements and seasonal home ranges of 6 GPS collared sika deer were investigated at the Oku-Chichibu Mountains, central Honshu, from April 2009 to March 2010. All deer migrated between discrete summer and winter home ranges. The linear migration distance ranged from 2.5 to 31.9 km. Mean elevation during the summer and the winter ranged from 980 to 1,782 m, and from 1,204 to 1,723 m, respectively. Two deer were upward migrants and 4 deer were downward migrants. Taking into consideration of the relatively small snow accumulation in the summer home range, the possibility of autumn migration to avoid deep snow is low. The percentage of steep slope in the winter home range was higher than that in the summer. Bamboo grass was not found in the summer home range, but was predominant in the winter home range. Road density decreased in the winter home range compared to the summer. Only 2 out of 6 deer stayed mainly in the wildlife protection area during the winter. Our results indicate that the autumn migration was affected by winter forage and human disturbance, thereby assured the survival of the deer during winter. © The Mammal Society of Japan.
Ochiai K.,Natural History Museum Institute |
Susaki K.,Asumigaoka |
Mochizuki T.,Akatsuki Wildlife Research Office |
Okasaka Y.,Japanese Serow Research Group |
Yamada Y.,Wildlife Management Office Inc.
Mammal Study | Year: 2010
To elucidate the relationships between the Japanese serow (Capricornis crispus) and their habitat, we conducted a survey of the population density, home range size, reproductive performance, and forage quality and availability mainly in winter. We compared these traits among three populations living in different habitats, Shimokita, Asahi and Kamikochi, based on field observation and published data. Reproductive rate, based on the number of kids that mothers reared to one year old, was highest for Shimokita (37.0%), followed in order by Asahi (29.6%) and Kamikochi (12.0%). Correlations were found among winter forage availability, home range size, reproductive rate and population density, when evergreen coniferous species were considered to have low food value for serows. We concluded that all of these factors could be useful indicators of habitat quality for the Japanese serow. The present results suggest that a small range size and high reproductive success, supported by appropriate food conditions, result in a high population density of the Japanese serow in mild habitats such as Shimokita, whereas the opposite is true in severe habitats such as Kamikochi. © 2010 the Mammalogical Society of Japan.
Soga A.,Tokyo University of Agriculture and Technology |
Hamasaki S.I.,Wildlife Management Office Inc. |
Yokoyama N.,Wildlife Management Office Inc. |
Sakai T.,Central Japan Railway Company |
Kaji K.,Tokyo University of Agriculture and Technology
Human-Wildlife Interactions | Year: 2015
Collisions between trains and sika deer (Cervus nippon) cause various problems involving animal and humans safety, as well as economic cost. A better understanding of deer crossing railway lines and deer-train accidents is necessary to develop effective mitigation measures. We investigated the collisions among habitat selection, railway-line crossing movement, and deer-train collisions. We predicted that the risk of deer-train collisions would increase with increasing probability of deer crossing railway lines, which is related to habitat selection surrounding in those areas. Deer stayed in forests to rest during the day and moved to grasslands or rice paddy fields to forage at night. Deer made exploratory crossings of rail lines and returned to the main side in a short time. The probability of crossing had negative effects on the risk of deer-train collisions because of trains' high visibility to deer. The risk of deer-train accidents increased with increasing forest cover, indicating that deer density might be the main factor causing deer-train collisions. Our study suggests that integrated studies on deer habitat selection, movement, and deer-train collisions are useful for wildlife management and transportation agencies to plan mitigation measures. The reduction of deer density within high-accident risk areas will reduce collisions.
Takatsuki S.,Azabu University |
Kobayashi M.,Wildlife Management Office Inc. |
Katayama A.,Wildlife Management Office Inc.
Mammal Study | Year: 2011
We analyzed 78 rumen content samples obtained in middle and southern parts of Wakayama Prefecture, the southern-most part of Honshu, the main island of Japan from 1995 to 1998. The rumen contents were dominated by browse (leaves of woody plants). Evergreen broad-leaves such as Quercus spp., Eurya japonica, Ligustrum japonicum, and Aucuba japonica were dominant, occupying 30-45%. Deciduous broad-leaves including Rubus spp., Hydrangea luteo-venosa, and Callicarpa mollis accounted for 20-35%. Forbs accounted for 10-20%. Non-synthetic organs like twigs and bark accounted for only 2-5%, and graminoids and ferns appeared little. These results suggest that foods of the Wakayama deer are good in quality, particularly in winter. The comparison has shown that the Wakayama deer are categorized into the typical southern browser type. Geographical variations of the food contents of sika deer are demonstrated by greater contributions of graminoids as well as by summer-winter differences in the northern grazer type than the southern browser type. Percentage similarity (PS, Whittaker 1952) well demonstrated seasonal variations of dietary compositions. © the Mammalogical Society of Japan.