Japan Wildlife Research Center

Sumida-ku, Japan

Japan Wildlife Research Center

Sumida-ku, Japan
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Yabe T.,Rat Control Consulting | Horikoshi K.,Institute of Boninology | Hashimoto T.,Japan Wildlife Research Center
Pacific Science | Year: 2017

We investigated the cause of extraordinarily small body mass in Norway rats (Rattus norvegicus) living in the Ogasawara (Bonin) Islands in the subtropical climate zone in Japan. We compared body masses of Norway rats living in four localities, the Hahajima group of the Ogasawara Islands, uninhabited islands in Hokkaido in the subarctic climate zone, a business district in Yokohama, and an artificial islet in Tokyo Bay in the temperate climate zone. Regressions of body mass and age (in months; estimated from lens weight) showed that weights of Norway rats on the Hahajima Islands were about half the weights of rats in the other three localities. Crown length of the maxillary molar row was similar in three localities ( Hahajima, Hokkaido, and Yokohama), and both the head - body length and the tail length were similar in Hahajima and Hokkaido, suggesting that the low body mass of the Hahajima rats was due to environmental factors rather than genetic factors. Stomach contents of Norway rats on the Hahajima Islands were predominantly (95.2% by vol.) plant matter, which is not the usual food preference for the species. We hypothesize that a low-protein diet restricts body mass of Norway rats on the Ogasawara Islands. © 2017 by University of Hawai'i Press.All rights reserved.


Yabe T.,Asia Center | Minato R.,Japan Wildlife Research Center | Hashimoto T.,Japan Wildlife Research Center
Russian Journal of Theriology | Year: 2017

We analyzed age distribution of Norway rats (Rattus norvegicus) on uninhabited islands, Yururi (168 ha) and Moyururi (31 ha) in the subarctic climate zone in Hokkaido, Japan. Age was estimated from eye lens weight. From the age distribution of 73 rats caught in July-August 2013, we found that 10 rats of them were born under the snow cover from December to March. © Russian Journal Of Theriology, 2017.


Sekiyama M.,University of Tokyo | Roosita K.,Bogor Agricultural University | Ohtsuka R.,Japan Wildlife Research Center
Nutrients | Year: 2017

School lunch is not provided in public elementary schools in Indonesia, and students frequently buy and eat snacks at school. We hypothesized that providing a traditional Sundanese meal as school lunch would be beneficial for children in rural West Java. To test this hypothesis, we evaluated the effect of a 1-month school lunch intervention aiming at sustainability and based on children’s nutritional intake, hemoglobin and hematocrit levels, and body mass index (BMI). A lunch (including rice, vegetable dish, animal protein dish, plant protein dish, and fruit) containing one-third of the recommended daily allowance of energy was offered every school day for 1 month, targeting 68 fourth-grade elementary schoolchildren. At baseline, the prevalence of anemia was 33.3%. The prevalence of stunting and underweight were 32.4% and 2.9%, respectively, whereas that of overweight and obesity combined was 17.6%, indicating a double burden of malnutrition among the subjects. During the intervention, intakes of protein (p < 0.05), calcium (p < 0.05), and vitamin C (p < 0.001) significantly increased, while that of fat significantly decreased (p < 0.001). After the intervention, hemoglobin (p < 0.05) and hematocrit (p < 0.05) levels were significantly improved, thereby almost halving the rate of anemia. These changes were significantly larger in the baseline anemic group than the non-anemic group (p < 0.01). BMI significantly increased in the baseline underweight/normal group (p < 0.001) but not in the overweight/obese group. The school lunch intervention significantly improved nutritional intakes and health statuses, implying its potential for reducing anemia and resolving the double burden of malnutrition among rural Indonesian schoolchildren. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.


Toda M.,Japan Wildlife Research Center
Japanese Journal of Conservation Ecology | Year: 2013

I investigated populations of the forest green treefrog Rhacophorus arboreus in relation to changes in its habitat at Kanazawa Castle (Ishikawa Prefecture, Japan) during the period 1984-2012. There were no marked population fluctuations from the 1980s through the mid 1990s, but frog numbers declined rapidly around the turn of the millenium. Population numbers increased again in the middle of the first decade of the new century, and frog densities have been high since about 2010. Although the locations of the ponds that served as breeding sites for this species shifted, because of changes in land-use in the late 1990s, there were always a number of different breeding sites available to the frogs. I did not identify the predominant factors associated with population size variability, but environmental changes in breeding sites probably played a part. Conservation of multiple breeding sites within the habitat range of the forest green treefrog is, therefore, considered important for the protection of this species. Exclusion of alien predators from breeding sites and provision of barrier-free routes between breeding sites are also considered crucial for conservation.


Yasukochi Y.,Graduate University for Advanced Studies | Kurosaki T.,Japan Wildlife Research Center | Yoneda M.,Japan Wildlife Research Center | Koike H.,Kyushu University | Satta Y.,Graduate University for Advanced Studies
BMC Evolutionary Biology | Year: 2012

Background: The major histocompatibility complex (MHC) genes are one of the most important genetic systems in the vertebrate immune response. The diversity of MHC genes may directly influence the survival of individuals against infectious disease. However, there has been no investigation of MHC diversity in the Asiatic black bear (Ursus thibetanus). Here, we analyzed 270-bp nucleotide sequences of the entire exon 2 region of the MHC DQB gene by using 188 samples from the Japanese black bear (Ursus thibetanus japonicus) from 12 local populations. Results: Among 185 of 188 samples, we identified 44 MHC variants that encoded 31 different amino acid sequences (allotypes) and one putative pseudogene. The phylogenetic analysis suggests that MHC variants detected from the Japanese black bear are derived from the DQB locus. One of the 31 DQB allotypes, Urth-DQB*01, was found to be common to all local populations. Moreover, this allotype was shared between the black bear on the Asian continent and the Japanese black bear, suggesting that Urth-DQB*01 might have been maintained in the ancestral black bear population for at least 300,000 years. Our findings, from calculating the ratio of non-synonymous to synonymous substitutions, indicate that balancing selection has maintained genetic variation of peptide-binding residues at the DQB locus of the Japanese black bear. From examination of genotype frequencies among local populations, we observed a considerably lower level of observed heterozygosity than expected. Conclusions: The low level of observed heterozygosity suggests that genetic drift reduced DQB diversity in the Japanese black bear due to a bottleneck event at the population or species level. The decline of DQB diversity might have been accelerated by the loss of rare variants that have been maintained by negative frequency-dependent selection. Nevertheless, DQB diversity of the black bear appears to be relatively high compared with some other endangered mammalian species. This result suggests that the Japanese black bears may also retain more potential resistance against pathogens than other endangered mammalian species. To prevent further decline of potential resistance against pathogens, a conservation policy for the Japanese black bear should be designed to maintain MHC rare variants in each local population. © 2012 Yasukochi et al.; licensee BioMed Central Ltd.


Dobata S.,University of Tokyo | Dobata S.,University of Ryukyus | Sasaki T.,University of Ryukyus | Sasaki T.,Fumakilla Ltd. | And 5 more authors.
Molecular Ecology | Year: 2011

How cooperation can arise and persist, given the threat of cheating phenotypes, is a central problem in evolutionary biology, but the actual significance of cheating in natural populations is still poorly understood. Theories of social evolution predict that cheater lineages are evolutionarily short-lived. However, an exception comes from obligate socially parasitic species, some of which thought to have arisen as cheaters within cooperator colonies and then diverged through sympatric speciation. This process requires the cheater lineage to persist by avoiding rapid extinction that would result from the fact that the cheaters inflict fitness cost on their host. We examined whether this prerequisite is fulfilled, by estimating the persistence time of cheaters in a field population of the parthenogenetic ant Pristomyrmex punctatus. Population genetic analysis found that the cheaters belong to one monophyletic lineage which we infer has persisted for 200-9200 generations. We show that the cheaters migrate and are thus horizontally transmitted between colonies, a trait allowing the lineage to avoid rapid extinction with its host colony. Although horizontal transmission of disruptive cheaters has the potential to induce extinction of the entire population, such collapse is likely averted when there is spatially restricted migration in a structured population, a scenario that matches the observed isolation by distance pattern that we found. We compare our result with other examples of disruptive and horizontally transmissible cheater lineages in nature. © 2010 Blackwell Publishing Ltd.


Furusawa T.,Kyoto University | Sirikolo M.Q.,National Herbarium and Botanical Gardens | Sasaoka M.,Hokkaido University | Ohtsuka R.,Japan Wildlife Research Center
Journal of Ethnobiology and Ethnomedicine | Year: 2014

Background: In Solomon Islands, forests have provided people with ecological services while being affected by human use and protection. This study used a quantitative ethnobotanical analysis to explore the society-forest interaction and its transformation in Roviana, Solomon Islands. We compared local plant and land uses between a rural village and urbanized village. Special attention was paid to how local people depend on biodiversity and how traditional human modifications of forest contribute to biodiversity conservation.Methods: After defining locally recognized land-use classes, vegetation surveys were conducted in seven forest classes. For detailed observations of daily plant uses, 15 and 17 households were randomly selected in the rural and urban villages, respectively. We quantitatively documented the plant species that were used as food, medicine, building materials, and tools.Results: The vegetation survey revealed that each local forest class represented a different vegetative community with relatively low similarity between communities. Although commercial logging operations and agriculture were both prohibited in the customary nature reserve, local people were allowed to cut down trees for their personal use and to take several types of non-timber forest products. Useful trees were found at high frequencies in the barrier island's primary forest (68.4%) and the main island's reserve (68.3%). Various useful tree species were found only in the reserve forest and seldom available in the urban village. In the rural village, customary governance and control over the use of forest resources by the local people still functioned.Conclusions: Human modifications of the forest created unique vegetation communities, thus increasing biodiversity overall. Each type of forest had different species that varied in their levels of importance to the local subsistence lifestyle, and the villagers' behaviors, such as respect for forest reserves and the semidomestication of some species, contributed to conserving diversity. Urbanization threatened this human-forest interaction. Although the status of biodiversity in human-modified landscapes is not fully understood, this study suggested that traditional human modifications can positively affect biodiversity and that conservation programs should incorporate traditional uses of landscapes to be successful. © 2014 Furusawa et al.; licensee BioMed Central Ltd.


Sueyoshi S.,Kibi International University | Ohtsuka R.,Japan Wildlife Research Center
Biodemography and Social Biology | Year: 2010

An interview survey of 450 Muslim women in a rural village of south Jordan under the early stage of fertility transition was conducted to explore major causes of contraceptive use, taking both their sociodemographic attributes and fatwa (Islamic jurisprudence)-based perception into account. Discriminant analysis, which was performed for the subject women divided into 15- to 29-, 30- to 39-, and 40- to 49-year age groups, revealed that "the number of living children" in the former and "to do contraception for good care of children" in the latter played significant roles in discrimination into contraceptive user and nonuser groups for any age groups. To cope with demographically and socioeconmically vulnerable situations, contraceptive prevalence rate should be increased by means of government-led family planning programs in cooperation with the imam (Muslim religious leaders and priests) through fatwa, in which special attention is paid to traditional norms, represented by good childcare. Copyright © Society for the Study of Social Biology.


Sekiyama M.,University of Tokyo | Roosita K.,Bogor Agricultural University | Ohtsuka R.,Japan Wildlife Research Center
Asia Pacific Journal of Clinical Nutrition | Year: 2012

Dietary habits of children, including snack foods consumption, in developing countries have seldom been investigated in relation to their nutrition and health. To assess the effects of snack foods consumption of 154 children aged 1-12 years in a rural village of West Java, Indonesia, a 3-hour-interval food recall survey for all meals and snack foods consumed in seven consecutive days for each subject, anthropometry, and interviews for sociodemographic indicators were conducted. Their overall prevalence of stunting and underweight was 69.5% and 35.7%. There were 221 foods consumed by the subjects, among which 68 foods were categorized as snack foods. Though the children of both <7 year and ≥7 year age groups consumed snack foods similarly throughout the day, the latter group only consumed larger amounts of energy from snack foods at school recess-times. The mean percent contribution of snack foods was 59.6% for fat, 40.0% for energy, 20.6% for calcium, and <10% for vitamins A and C. Half number of the subjects who snacked more than the median amount consumed less carbohydrate and vitamin C than the remaining half. Furthermore, the more snack-consuming group the lower z score for height-for-age (HAZ) among schoolchildren. To improve this nutritionally vulnerable situation, consumption of snack foods should be replaced by the non-snack foods which contain much higher nutrient density, i.e., 15 times for calcium and 32 times for vitamin A. Moreover, considering high snack foods consumption of ≥7 y age group at school, appropriate school nutrition programs should be promoted.


Sekiyama M.,University of Tokyo | Roosita K.,Bogor Agricultural University | Ohtsuka R.,Japan Wildlife Research Center
American Journal of Physical Anthropology | Year: 2015

This study investigated the growth trajectories and the relative relevance levels of nutrition, disease, and hormonal status at various developmental stages among children in adverse environments to provide population-based empirical evidence for the life history theory. Three years of longitudinal anthropometric data in 1-year intervals were obtained from 418 boys and girls aged 0 to 12 years at recruitment. Following the final measurement, the main survey, which included blood and feces sampling, 3-h interval food consumption recall surveys for energy and nutrient intakes and anthropometry, was performed. Blood and feces were used for detecting, respectively, anemia and hormonal (IGF-I and IGFBP-3) levels as well as intestinal helminthiasis (Ascaris, Trichuris, and hookworm). The major findings of this study are summarized as follows: 1) the growth velocity of the subject children lagged behind international standards during childhood and juvenility but caught up during early adolescence; 2) diseases, both intestinal helminths and anemia, had significant effects on growth in childhood but not at older ages; and 3) hormonal status significantly affected growth in the children, with its highest significance in early adolescence. A larger growth than international standards in early adolescence likely follows programmed hormonal mechanisms after the onset of puberty. The onset of puberty might be associated with adequate amounts of nutrient intake and be mediated by hormonal function, because the IGF-IZ score was significantly correlated with energy and protein intakes at the transitional period from juvenility to adolescence, when puberty occurs. Am J Phys Anthropol 157:94-106, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

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