Tropics
Online ISSN : 1882-5729
Print ISSN : 0917-415X
ISSN-L : 0917-415X
23 巻, 4 号
選択された号の論文の8件中1~8を表示しています
ORIGINAL ARTICLES
  • Eiji Inoue, Etienne François Akomo-Okoue
    2015 年 23 巻 4 号 p. 137-150
    発行日: 2015年
    公開日: 2015/03/01
    ジャーナル フリー
    The DNA barcoding of fecal samples was used to inventory large- and medium-sized terrestrial mammals in the African rain forest. First, the appropriate DNA region for the genetic identification of various species was determined. Although a region of mitochondrial cytochrome c oxidase I has been commonly used for DNA barcoding, the number of mammal species in which sequences of the region have been registered in the GenBank is limited, with the mitochondrial cytochrome b region (cytb) representing the most appropriate region for this type of analysis. Hence, genetic species identification was conducted using the mitochondrial cytb region for most samples, while the control region was used for small ungulates. We collected 259 fresh fecal samples of mammals in Moukalaba-Doudou National Park, Gabon. More than 70% of analyzed samples produced sequences. The species was identified by examining the sequence identity between the sample and the identified species and that between the sample and the next closest species, or by constructing a phylogenetic tree containing closely related species. In total, the sequences of 19mammal species were obtained. A smaller number of species were recorded by DNA barcoding compared to camera traps placed in the study area; however, DNA analyses were effective at discriminating morphologically similar species, such as small ungulates and carnivores, some of which were difficult to identify even when using camera traps. Genetic species identification using feces, in combination with direct observation and/or camera traps, can be useful for the accurate inventory of large- and medium-sized terrestrial mammals.
  • Yoshihiro Nakashima
    2015 年 23 巻 4 号 p. 151-164
    発行日: 2015年
    公開日: 2015/03/01
    ジャーナル フリー
    I compiled a list of medium- and large-sized mammals (excluding Rodentia) in Moukalaba-Doudou National Park, Gabon. Additionally, I evaluated the efficiency of camera trapping for inventorying these animals. I placed 125 camera traps (set to “video mode”) in forest and savannah in the eastern regions of the park, and compared my data with visual and acoustic observational records from the study area since 1999. I confirmed the occurrence of 38species (11Primates, 13 Carnivora, nine Ungulates, and five other taxa). During 4165 camera-days, my camera traps detected 29 out of the 38species (76%), including 10 newly-recorded species in the study area. However, a high proportion of cameras (40%) in savannah were destroyed by Loxodonta africana. Furthermore, using this technique, it was difficult to detect arboreal species. It was also difficult to discriminate morphologically similar species (Cephalophus spp., Phataginus spp., and Galago spp.) from the captured images. These species can be more appropriately detected by visual sighting, acoustic hearing, and molecular techniques, suggesting that a combination of these techniques may increase the inventory efficiency. The number of forest-dwelling herbivores was lower in Moukalaba than in four other sites at or near Gabon, possibly because of separation from large Pleistocene refuges by a natural boundary. Nevertheless, Moukalaba harbors two savannah-dwellers─Kobus ellipsiprymnus and Herpestes ichneumon─which inhabit only a few protected areas of Gabon. The forest is invading the savannah, and therefore there is a requirement for regular burning, which must be enforced to preserve the totality of the existing biodiversity.
  • Pierre Philippe Mbehang Nguema, Sayaka Tsuchida, Kazunari Ushida
    2015 年 23 巻 4 号 p. 165-174
    発行日: 2015年
    公開日: 2015/03/01
    ジャーナル フリー
    Culturing the intestinal bacteria of wild animals is a difficult task under field conditions, although isolation and characterization of bacteria are absolutely necessary to evaluate the transmission of bacteria from human to animal or vice versa. We have developed a protocol for intestinal bacteria culturing from feces of wild animals such as gorillas in Moukalaba-Doudou National Park in Gabon, where no laboratory settings were available. The prevalence of resistance genes in Enterobacteriaceae isolates estimated by real time PCR array was higher for aminoglycosides resistance, followed by tetracycline resistance, except for possible naturally occurring β-lactam resistance. The detection level of resistance genes was higher for isolates from humans than those from gorillas. Occasional monitoring of this prevalence may help to measure the intensity of introduction of human-borne bacteria to wildlife.
  • Sayaka Tsuchida, Kazunari Ushida
    2015 年 23 巻 4 号 p. 175-183
    発行日: 2015年
    公開日: 2015/03/01
    ジャーナル フリー
    Intestinal microbiota play an important role in digestion and host’s health. Furthermore, their composition is complex, with large differences between animal species. Intestinal microbiota have been intensively studied in humans, whereas those in animals, especially in the wild, have not been thoroughly studied. In this study, we focused on the intestinal microbiota of wild western lowland gorillas, chimpanzees, and an elephant in Moukalaba-Doudou National Park in Gabon by using pyrosequencing analysis for understanding their characteristics. Pyrosequencing of their fecal samples yielded 16,898 reads with a read length of 390 nucleotides (10,860,585 nucleotides in total) on average, and taxonomic analysis of metagenomic reads was performed by BLAST search. In almost all animal feces, Prevotellaceae, Clostridiaceae, and Lachnospiraceae were detected as major bacterial families. At the genus level, no-rank Operational Taxonomic Units (OTUs), 80%-90% identities with known sequences, covered a major of fecal microbiota which seemingly determine the enterotype of the host. However, in principal coordinate analysis using weighted UniFrac, their fecal bacteria were clustered by species of host. The result in the present study suggests that it is necessary that no-rank OTUs and minor populations of the fecal bacteria should be analyzed in detail to understand the true characteristics such as functionality of intestinal microbiota.
  • Yuji Takenoshita
    2015 年 23 巻 4 号 p. 185-193
    発行日: 2015年
    公開日: 2015/03/01
    ジャーナル フリー
    African great apes are threatened with extinction by an increasing number of human activities. Along with an increase in the habitat overlap used by local people and great apes, human-great ape conflicts have become intense. Many protected areas have recently been established for the conservation of great apes and other biodiversity in Africa, but difficulties have arisen while adopting the “fences-and-fines” management approach. Tourism could provide an alternative approach for the management of protected areas as a sustainable use of biodiversity, and an alternative source of income for local communities and governments of countries with this type of habitat. However, with few exceptions, great ape tourism projects are faced with challenges. Moreover, great ape tourism increases the risks of disease transmission between humans and great apes. Nevertheless, great apes, as charismatic flagship species, are essential for successful wildlife tourism. In this paper, I reconsider the current style of great ape tourism that depends on close visual contact between tourists and great apes. Then, I propose a novel style of great ape tourism. It is based on using narratives about great apes generated by local community members as the leading tour product, and visual contact as the supplementary product. This approach might 1) reduce the negative effects of tourism on great apes; and 2) enhance proactive commitment by community members, and lead to a fair revenue sharing system.
  • Naoki Matsuura, Guy-Max Moussavou
    2015 年 23 巻 4 号 p. 195-204
    発行日: 2015年
    公開日: 2015/03/01
    ジャーナル フリー
    It is important for the development of conservation projects to establish collaborative relationships with local populations, and for that, a detailed understanding of local lifestyles is required. In particular, basic information on local people’s natural resource utilization is essential. In this article, the authors analyzed livelihoods in Moukalaba-Doudou National Park (MDNP), southwestern Gabon based on quantitative data obtained from long-term field research. It was shown that people inhabiting the area around the MDNP depend heavily on natural resources for their livelihoods and they produced sufficient food within the region. However, it was also shown that the variety of food items was poor compared with other protected area in Africa and the nutritional status is presumed to have been inadequate. When compared with the data before the establishment of the National Park in 2002, consumption of bush meat decreased remarkably whereas that of fish only slightly increased after ten years. It is supposed that the people around the MDNP have converted their lifestyles flexibly to coexist with the conservation projects in a part, but it is also the fact that conservation practices threaten local livelihoods to some extent.
  • Takakazu Yumoto, Mari Terakawa, Saeko Terada, Archange Boupoya, Thomas ...
    2015 年 23 巻 4 号 p. 205-213
    発行日: 2015年
    公開日: 2015/03/01
    ジャーナル フリー
    Although the Congo River Basin contains the second largest tropical rainforest in the world, tropical Africa has fewer tree census plots than tropical Asia or America. Thus, more data are needed to describe species richness and diversity. We conducted a tree census to reveal the species richness and composition of a middle-altitude forest in Moukalaba-Doudou National Park, Gabon. We set a 150×150-m plot (2°3.2’S, 10°25.0’E) at an altitude of 220m. All trees >10cm in diameter at breast height (DBH) were marked, and the DBH of each was measured. We recorded 988trees, 692 (70.0%) of which were fully identified to 63species. Among the rest, 267trees (27.0%) were classified into 27genera, and 22trees (2.23%) were classified into 10 families. The 6most common species accounted for 50.6% (500trees) of the total number of trees: Dichostemma glaucescens (Euphorbiaceae), Diospyros sp. 1 (Ebenaceae), Strombosia pustulata (Olacaceae), Synsepalum longecuneatum (Sapotaceae), Staudtia kamerunensis var. gabonensis (Myristicaceae) and Pausinystalia macroceras (Rubiaceae). The remaining 86species had <10trees per ha, and 42species of these had <1tree per ha on average. These low-density species reflect a high-diversity forest.
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