Mammal Study
Volume 39, Issue 2, 2014
Volumes & issues:
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ORIGINAL PAPER
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Habitual Bark Gleaning by Cambodian Striped Squirrels Tamiops rodolphii (Rodentia: Sciuridae) in Cat Tien National Park, South Vietnam
View Description Hide DescriptionAbstract.Bark gleaning, habitual foraging over the bark of very wide vertical arboreal substrates by claw clinging and climbing with extremely abducted limbs, represents one of the most interesting squirrel adaptations and is associated with the morphologically specialized pygmy squirrels. However, this behavior may be also common in other small squirrels, such as Cambodian striped squirrels (Tamiops rodolphii) that lack similar apomorphies. In effect, field research and video analysis in southern Vietnam revealed that T. rodolphii is characterized by frequent use of large vertical substrates and engages in high percentages of clawed climbing and clawed clinging, comparable, albeit lower, to those of pygmy squirrels. Actually, this squirrel species, and its closest congener, T. macclellandi, may represent the early representatives of a small squirrel radiation that shifted to bark gleaning, taking advantage of their small size. Finally, the fact that bark gleaning squirrel species, with or without morphological specializations, are located in the forests of South America, Central Africa and South East Asia indicates the importance of bark foraging niche across tropical forests.
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Indirect estimation of Recent Sika Deer (Cervus nippon) Migration in Tsurugi Quasi-National Park, Shikoku, Japan
View Description Hide DescriptionAbstract.To provide information for the management of sika deer in Tsurugi Quasi-National Park, Shikoku, Japan, we analyzed population genetic structure and migration patterns in the national park and surrounding areas based on from six to seven microsatellite loci using tissue and fecal samples. Bayesian clustering divided the deer into two populations, the Tokushima population and the Kochi population. Twenty-four of 28 samples on Mt. Tsurugi were assigned the Kochi population and the spatial boundary between the two populations was found in the foothills of the Tsurugi mountain range. These results suggest that the invasion of sika deer into Tsurugi Quasi-National Park may have started from the foothills of the Tsurugi mountain range by expansion of the Kochi population. Therefore, proper management of Kochi population is crucial in preventing further migration of sika deer into Tsurugi Quasi-National Park.
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Ag-NORs Analysis in Three Species of Red-Backed Voles, with a Consideration of Generic Allocation of Anderson's Red-Backed Vole
View Description Hide DescriptionAbstract.To further make karyotaxonomic characterization of Anderson's red-backed vole (Eothenomys andersoni) certain, Ag-NOR-carrying chromosomes were identified by sequential G-band/silver staining in the red-backed voles Myodes (formerly Clethrionomys) rufocanus (Mru), E. andersoni (Ean), and E. smithii (Esm). These voles had the same diploid number (2n = 56), and their karyotypes scarcely differed from each other in chromosome constitution and G-banding pattern. Ag-NORs from these voles were all centromere-cap (cmc) type, being located at the tip of minute short arms of acrocentric chromosomes. Ten pairs of autosomes carried Ag-NORs in Mru, while Ean and Esm carried those on nineteen pairs of autosomes. Ean shared Ag-NORs with Esm on nos. 2, 5, 7, 10, and 13, but not with Mru at all, although nos. 3, 6, 8, 12, 19, 20, 22, 23, and 26 had Ag-NORs in common among three species. These Ag-NORs varied extensively in number from cell to cell with a range of 9–14 in Mru, 14–22 in Ean and 8–22 in Esm. No evidence of Ag-NORs was obtained on the sex chromosomes XY or on nos. 11, 14, and 27 in either species. These findings may be cytological evidence supporting the view of Aimi ( 1980 ) who ranked Anderson's red-backed vole as Eothenomys.
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Effectiveness of Noninvasive DNA Analysis to Reveal Isolated-Forest Use by the Sable Martes zibellina on Eastern Hokkaido, Japan
View Description Hide DescriptionAbstract.In order to assess importance of isolated forests as the wintering habitat of the sable (Martes zibellina) in eastern Hokkaido, Japan, we performed DNA analyses on 59 samples noninvasively collected in field (54 fecal, 3 urine and 2 hair samples). Consequently, 46 (41 fecal, 3 urine and 2 hair samples) of the 59 samples were recognized to have dropped from the sable. In addition, we successfully identified the individuality on 36 (35 fecal and 1 urine samples) of the 46 samples, and they consisted of at least 23 individuals. Our new method using sex chromosomal DNA markers showed that the 23 individuals comprised 12 males, 9 females and 2 with unknown sex. In 2010 and 2011, the minimum number of individuals in the study area was 21 (11 males, 8 females and 2 with unknown sex) and 5(1 male and 4 females), respectively. In addition, we found the sexual difference in fidelity to their home range. Thus, our noninvasive DNA technique provided promising information on estimating and monitoring ecological features about the regional sable population.
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Shape variation in the Skull Within and Between Wild Populations of the Raccoon Dog (Nyctereutes procyonoides) in Japan
View Description Hide DescriptionAbstract.Patterns of evolution can be biased by patterns of variability (propensity to vary). However, the effects of variability on evolution at the geographic and inter-subspecies levels have not been investigated extensively. Variation between different populations is the result of evolution. Individual variation within a single population can be indicative of species variability. Therefore, comparing patterns of variation within and between populations can reveal the effects of variability on evolution. In this study, I used two-dimensional geometric morphometric methods to evaluate variation in the shape of raccoon dog skulls within and between wild populations in Japan. In three of the populations observed, the dominant individual variation was cranial tilting. Cranial tilting is also a major variation between Japanese populations that has no correlation with climatic factors. However, differences in another morphological trait involving the frontal bone, parietal bone, and zygomatic arch dominated the variation between the Hokkaido population and other populations in Japan that are often considered to be a different subspecies. This morphological trait was correlated to snowfall. In conclusion, at the intra-subspecies level, morphological evolution in the skull is neutrally driven by variability. However, at the inter-subspecies level, adaptation may have a relatively larger effect on morphological evolution.
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SHORT COMMUNICATION
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Influence of Landscape Attributes on American Black Bear Den-Site Selection in Mississippi
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Does Boat Noise Affect Dugong (Dugong dugon) Vocalization?
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