著者
Masahiro Yamada Eiji Hosoi Hidetoshi B. Tamate Junco Nagata Shirow Tatsuzawa Hiroyuki Tado Shinobu Ozawa
出版者
THE MAMMAL SOCIETY OF JAPAN
雑誌
Mammal Study (ISSN:13434152)
巻号頁・発行日
vol.31, no.1, pp.23-28, 2006 (Released:2006-07-08)
参考文献数
17
被引用文献数
22

Nucleotide sequences of sika deer (Cervus nippon) collected from the eastern part of Shikoku Island were investigated & compared with those from other areas. Nucleotide sequence of the whole D-loop region of the mitochondrial DNA was determined by direct sequencing technique for each sample. The phylogenetic tree constructed by the sequences indicates that sika deer from Shikoku Island are divided into two distinct lineages: the northern Japan group and the southern Japan group. Proportion of the northern Japan lineage was higher in the northeastern part of the sampling area. There was no border between the distribution of the two lineages, rather it seemed that their distribution intermingled. Besides, there were locations where both lineages were found within a small area. These results indicate that two lineages might be hybridized in some areas of eastern Shikoku.
著者
Ishii Midori Murase Hiroto Fukuda Yoshiaki Sawada Kouichi Sasakura Toyoki Tamura Tsutomu Bando Takeharu Matsuoka Koji Shinohara Akira Nakatsuka Sayaka Katsumata Nobuhiro Okazaki Makoto Miyashita Kazushi Mitani Yoko
出版者
The Mammal Society of Japan
雑誌
Mammal study (ISSN:13434152)
巻号頁・発行日
vol.42, no.4, pp.191-199, 2017-12
被引用文献数
12

In this study, we investigated the diving behavior of sei whales relative to the vertical -distribution of their potential prey in the western North Pacific during the summer of 2013. Acoustic time-depth transmitters were attached to two sei whales for 10.2 and 32.0 h, respectively. The vertical distribution and density (expressed as the volume backscattering strength, SV) of their potential prey were recorded by an echosounder. Diving behavior was classified into two shapes: U-shaped and V-shaped. For both individuals, U-shaped diving was associated with higher SV values than V-shaped diving and the frequency of U-shaped diving increased from late afternoon until sunset. During the daytime, dense scattering layers (presumably zooplankton) were distributed at approximately 40 m and they then migrated toward the surface around sunset. The diving depth of the whales followed the diel migration of the scattering layers and the diving was concentrated in these layers when the density became high. The results of this study indicate that sei whales change their diving depth and shapes in response to the diel vertical migration of their potential prey.
著者
Masahiro Yamada Eiji Hosoi Junco Nagata Hidetoshi B. Tamate Hiroyuki Tado
出版者
日本哺乳類学会
雑誌
Mammal Study (ISSN:13434152)
巻号頁・発行日
vol.32, no.3, pp.121-127, 2007 (Released:2007-10-10)
参考文献数
22
被引用文献数
13 2

Samples of the sika deer (Cervus nippon) were collected from Kyushu and Shikoku Islands of Japan and surrounding areas, and their nucleotide sequences were analyzed. Sequences of the whole control region of the mitochondrial DNA were determined and phylogenetic trees were constructed using the neighbor-joining method and the maximum likelihood method. We also investigated gene genealogies for the sequences using the statistical parsimony network approach. Phylogenetic trees showed that only the Yakushima/Tanegashima populations were genetically distant from other populations. The statistical parsimony network, however, indicated a close relationship of the Miyazaki populations to some of the Shikoku populations. It was suggested that Shikoku Island played an important role in the divergence from the southern Japan lineage of C. nippon.
著者
Daichi Nabata Koichi Kaji Junco Nagata Ryuichi Masuda
出版者
日本哺乳類学会
雑誌
Mammal Study (ISSN:13434152)
巻号頁・発行日
vol.32, no.1, pp.17-22, 2007 (Released:2007-04-11)
参考文献数
17
被引用文献数
3 3

Recent overpopulation of the sika deer (Cervus nippon) in Hokkaido has resulted in expansion of their distribution from eastern to western parts of this island. To assess changes of genetic population structures of the Hokkaido sika deer, mitochondrial DNA control sequences (602 base-pairs) from 283 animals collected from central and western Hokkaido were analyzed. Based on transitional substitutions (A < - > G) at four nucleotide sites, five haplotypes were identified. One haplotype was newly found in the present study, and the other four haplotypes referred to those reported previously. The distribution patterns of haplotypes showed characteristic changes of genetic population structures, compared with the past distribution of haplotypes. In northern Hokkaido, for instance, the population around the Okhotsk Sea-coastal region has clearly expanded to the Japan Sea-coastal region. The population around the Ishikari-lowlands and the Hidaka mountains has increased within these areas, and it is not likely that the increase is directly caused by the immigration from eastern Hokkaido.
著者
Nozomi Nakanishi Maki Okamura Shinichi Watanabe Masako Izawa Teruo Doi
出版者
日本哺乳類学会
雑誌
Mammal Study (ISSN:13434152)
巻号頁・発行日
vol.30, no.1, pp.1-10, 2005 (Released:2005-07-14)
参考文献数
23
被引用文献数
10

The seasonal variation in home range size of one male and one female Iriomote Cat Prionailurus bengalensis iriomotensis was studied by radio-tracking and automatic photography on Iriomote Island, Japan. The study was conducted in the Shirahama area located in the western part of the island. Shirahama provides a small area of suitable lowland habitat (<50 m a.s.l.) for the Iriomote Cat. Two individuals, one male and one female, were confirmed to be resident in this area. The periodical home range size of the male was 1.24 ± 0.41 km2 and that of the female was 1.30 ± 0.54 km2 throughout the year, with no significant difference between them. We compared the results of these observations with those from another area of suitable habitat in Funaura and discussed what factors may affect male home range size. The home range of the male cat in Shirahama was found to be only half the size of that of males in Funaura, though it showed similar seasonal fluctuation. The home ranges of females were similar in the two areas. Our results provide empirical confirmation of the influence of the number and distribution of females on male home range size in a solitary felid.
著者
Takeo KAWAMICHI Samdannyamin DAWANYAM
出版者
THE MAMMAL SOCIETY OF JAPAN
雑誌
Mammal Study (ISSN:13434152)
巻号頁・発行日
vol.22, no.1+2, pp.89-93, 1997 (Released:2005-10-07)
参考文献数
10

We excavated a breeding nest of the Daurian pika, Ochotona daurica, in central Mongolia. Four young were captured within the burrows. Three food storage chambers contained plant fragments and a large amount of fecal matter, indicating that hoarded food had been consumed during the last winter. The nest chamber was spherical and measured 22×18×21 cm. Most of the nest chamber was filled with piles of grasses, and these piles were presumably their resting site. The burrow system had three entrances, and the nest chamber was connected to three burrows. Multiple nest entrances were provided ready access to refuge for pikas active on the ground surface from aerial and terrestrial predators, while multiple burrows also provide refuge against the intrusion of predators such as stoats into nest chambers.
著者
Kawada Shin-ichiro Shinohara Akio Yasuda Masatoshi ODA Sen-ichi LIAT Lim Boo
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.30, no.2, pp.109-115, 2005-12-01
被引用文献数
4 6

We report the first karyological description of a southeast Asian mole, the Malaysian mole (<i>Euroscaptor micrura malayana</i>). The karyotype of the Malaysian mole includes 36 chromosomes, which consist of 18 biarmed and 16 acrocentric autosomes and the sex pair. The sex chromosomes are a small meta-submetacentric X chromosome and a minute dot-like Y chromosome, although the latter is somewhat larger than that of some talpid allies. Autosomal complements include one pair of NOR-bearing chromosomes. A comparative G-banding analysis with the Japanese congener <i>E. mizura</i> showed that these two species share high G-banding homology, and their differences on two pairs of chromosomes are explained by a single reciprocal translocation. The karyological similarity of these distant geographic species is discussed in a systematic and evolutionary context, based on comparisons to other species distributed between them.<br>
著者
Shinohara Akio Campbell Kevin L. Suzuki Hitoshi
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.30, pp.S19-S24, 2005-12-01
被引用文献数
4 12

Japanese talpid moles exhibit a remarkable degree of species richness and geographic complexity, and as such, have attracted much research interest by morphologists, cytogeneticists, and molecular phylogeneticists. However, a consensus hypothesis pertaining to the evolutionary history and biogeography of this group remains elusive. Recent phylogenetic studies utilizing nucleotide sequences have provided reasonably consistent branching patterns for Japanese talpids, but have generally suffered from a lack of closely related South-East Asian species for sound biogeographic interpretations. As an initial step in achieving this goal, we constructed phylogenetic trees using publicly accessible mitochondrial and nuclear sequences from seven Japanese taxa, and those of related insular and continental species for which nucleotide data is available. The resultant trees support the view that four lineages (<i>Euroscaptor mizura</i>, <i>Mogera tokuade</i> species group [<i>M. tokudae</i> and <i>M. etigo</i>], <i>M. imaizumii</i>, and <i>M. wogura</i>) migrated separately, and in this order, from the continental Asian mainland to Japan. The close relationship of <i>M. tokudae</i> and <i>M. etigo</i> suggests these lineages diverged recently through a vicariant event between Sado Island and Echigo plain. The origin of the two endemic lineages of Japanese shrew-moles, <i>Urotrichus talpoides </i>and <i>Dymecodon pilirostris</i>, remains ambiguous. Further analyses on intra-species diversity are necessary to fully solve the evolutionary histories of Japanese moles and shrew-moles.<br>
著者
Hashimoto Takuma Abe Manabu
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.26, no.1, pp.35-44, 2001-06-01
被引用文献数
2 4

Two species of moles, <i>Mogera tokudae</i> and <i>M. imaizumii</i>, are parapatrically distributed in the Echigo Plain in the northern part of Niigata Prefecture, Japan. The two species are morphologically similar, except for the larger body size of <i>M. tokudae</i>. To clarify whether interspecific competition affects body size and reproductive traits of these moles, we compared these characteristics in syntopic populations with those in allopatric populations for both species in the Echigo Plain. <i>Mogera tokudae</i> exhibited little body size difference between allopatric and syntopic populations, while body size of <i>M. imaizumii</i> in syntopic populations was significantly smaller than in allopatric populations. Although litter sizes of both species were almost the same, reproductive schedules were different. Pregnant <i>M. tokudae</i> were captured mostly in late April, whereas <i>M. imaizumii</i> had a longer period of reproduction from March to October; some individuals bred twice a year. The relatively small body size and the longer breeding period observed in <i>M. imaizumii</i> of the Echigo Plain may be tactics for increasing reproductive success under severe interspecific competition from <i>M. tokudae</i>.
著者
Motokawa Masaharu Maeda Kishio
出版者
日本哺乳類学会
雑誌
Mammal study (ISSN:13434152)
巻号頁・発行日
vol.27, no.2, pp.145-147, 2002-12-01
被引用文献数
1