Mammals In Japan Research Articles

Pesticide Contamination Levels in the Stomach Contents of Wild Raccoons (Procyon lotor) and Masked Palm Civets (Paguma larvata) in Japan.

Pesticides, which are vital for agriculture, pose a significant threat to wildlife in transformed Japanese landscapes. Despite global reports of pesticide poisoning in animals, limited studies have examined current wildlife exposure in croplands or metropolitan areas in the region. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), our study aimed to assess the contamination status of 368 commonly used pesticides. The stomach contents of raccoons living in croplands contained 13 pesticides, including six herbicides and 11 fungicides. Neonicotinoid insecticides, some fungicides, and previously banned insecticides (benzene hexachloride and dichlofenthion) were most frequently detected and found at the highest concentrations, suggesting direct soil-plant transfer and direct consumption by crop-eating species. In masked palm civets living in metropolitan areas, four insecticides and six fungicides were detected, indicating urban wildlife exposure from raided dustbins, urban gardens, and lumber from houses. Although the maximum measured concentrations of all pesticides were lower than the acceptable daily intake for humans, it remains unclear whether these concentrations may have toxic or adverse health effects on the species evaluated in these transformed landscapes. Our study is the first to examine recent pesticide exposures in wild mammals in Japan. Application of the method we developed will lay the foundation for the examination of pesticides in other wildlife species to assist conservation management efforts in the region. Environ Toxicol Chem 2024;43:943-951. © 2024 SETAC.

Effects of intensive agricultural landscapes on farmland use by medium and large mammals in Japan

ABSTRACT This study aimed to determine the effects of landscape differences associated with intensive agricultural activities on farmland use by medium and large mammals in Japan. We compared the species diversity of mammals that used farmland within three regions with different agricultural activity levels, and analyzed the relationship between the occurrences and escape responses of mammals in the farmland and surrounding landscape. We used spotlight count in intensive (high agricultural activity), intermediate (moderate agricultural activity), and non-intensive (low agricultural activity) areas. We observed 271 and 199 occurrences of mammals in spring and autumn 2021, respectively. Seasonal changes in mammals occurrence were due to a decrease in the number of raccoon dogs observed. Species richness tended to be lower in intensive agricultural areas than in other areas, suggesting that intensive agricultural landscapes negatively affect the community structure of medium and large mammals. Generalized additive models showed that the effects of the surrounding landscape on the occurrences and escape responses of raccoon dogs, red foxes, and cats differed among species. Only raccoon dogs were negatively affected by the surrounding farmland, suggesting high sensitivity to agricultural activities. Our results have important implications for the management of ecosystems in Japanese agricultural areas.

Mitigating the effects of road construction on arboreal Japanese mammals: benefits for both wildlife and people

Abstract Fragmentation of forest habitat has negative effects on arboreal mammals, compromising their natural dispersal and foraging movements. This paper describes an evolving series of mitigation measures aimed at creating cost-effective continuity pathways for arboreal mammals in Japan. The projects have focused on the endemic Japanese dormouse (Glirulus japonicus) a scarce, but popular and iconic species which provides an effective vehicle for environmental education and public engagement.

Double-observer approach with camera traps can correct imperfect detection and improve the accuracy of density estimation of unmarked animal populations

Camera traps are a powerful tool for wildlife surveys. However, camera traps may not always detect animals passing in front. This constraint may create a substantial bias in estimating critical parameters such as the density of unmarked populations. We proposed the 'double-observer approach' with camera traps to counter the constraint, which involves setting up a paired camera trap at a station and correcting imperfect detection with a reformulated hierarchical capture-recapture model for stratified populations. We performed simulations to evaluate this approach's reliability and determine how to obtain desirable data for this approach. We then applied it to 12 mammals in Japan and Cameroon. The results showed that the model assuming a beta-binomial distribution as detection processes could correct imperfect detection as long as paired camera traps detect animals nearly independently (Correlation coefficient ≤ 0.2). Camera traps should be installed to monitor a predefined small focal area from different directions to satisfy this requirement. The field surveys showed that camera trap could miss animals by 3–40%, suggesting that current density estimation models relying on perfect detection may underestimate animal density by the same order of magnitude. We hope that our approach will be incorporated into existing density estimation models to improve their accuracy.

Zoonotic Infection with Oz Virus, a Novel Thogotovirus.

Oz virus is a novel thogotovirus isolated from ticks that causes lethal infection in mice. We conducted serosurveillance of Oz virus infection among humans and wild mammals in Japan using virus-neutralization tests and ELISAs. Results showed that Oz virus may be naturally infecting humans and other mammalian hosts.

Consumption of anthelmintic fox baits by target and non-target mammals in Japan

Consumption of anthelmintic fox baits by target and non-target mammals in Japan

Les faunes terrestres quaternaires des Îles du Japon

This paper explains a brief history of research on Quaternary terrestrial mammals in Japan and fossil occurrence of taxa at major localities of each time period at first. Based on these data, then, the changing history of Quaternary terrestrial mammals in Japan is reviewed, especially on such points as (1) importance of strait in western Japan as coming over route, (2) changing history of Plio-Pleistocene terrestrial mammals in Japan, (3) two faunas during the Late Pleistocene, (4) dates of extinctions of large mammals near the end of the Late Pleistocene. Formation process of Quaternary terrestrial mammal fauna in Japan must have been affected by condition of land connection with Asian continent at seaway west to Japan and changing history of climate and vegetation in East Asia, and it should be considered by different time period, e.g. before and after ca. 1.7 Ma. The time period after 1.7 Ma is one affected by glacial sea level fluctuations. Although a new fauna came over from the west to Japan when sea level was low, this time period is basically the age of insularization, and it is presumed that the fauna was becoming endemic during this time period. During the late Late Pleistocene, there were two faunas existed in Japan, e.g. one with Palaeoloxodon naumanni having come over from the west and another with Mammuthus primigenius having come over from the north. The former dwelled mainly in deciduous broad-leaved forest and mixed forest with conifers in temperate climate, while the latter dwelled in steppe and coniferous forest in subboreal climate. Both faunas changed their ranges to north and south repeatedly as climate changed, and the extinction of large mammals of the fauna with Palaeoloxodon naumanni occurred at the same time of the beginning of the LGM (ca. 25–16 ka). On the other hand, large mammals of the fauna with Mammuthus primigenius became extinct or moved to north as climate became warm quickly after the LGM. Thus, it is suggested that the extinction of large mammals at the late Late Pleistocene occurred by “two pulses.” The extinction process of large mammals in Japan seems likely that they went extinct finally near the end of the Pleistocene going through the reduction of habitat and fragmentation of populations caused by the repeated temperature change during the late Late Pleistocene, rather than a single drastic event.

Possible transmission of Sarcoptes scabiei between herbivorous Japanese serows and omnivorous Caniformia in Japan: a cryptic transmission and persistence?

BackgroundTwo transmission patterns of Sarcoptes scabiei in host mammal communities have been reported based on microsatellite-level genetic studies in the last two decades. While one involves restrictions among different host taxa, the other is associated with predator–prey interactions between different host taxa. In contrast to these observations, the present study reports a possible irregular case of transmission of S. scabiei between herbivorous Japanese serow and omnivorous Caniformia mammals in Japan, though under very weak predator–prey relationships.MethodsDNA from 93 Sarcoptes mites isolated from omnivorous Caniformia (such as the domestic dog, raccoon dog, raccoon and Japanese marten), omnivorous Cetartiodactyla (wild boar) and herbivorous Cetartiodactyla (Japanese serow) in Japan were analyzed by amplifying nine microsatellite markers. Principal components analyses (PCA), Bayesian clustering analyses using STRUCTURE software, and phylogenetic analyses by constructing a NeighborNet network were applied to determine the genetic relationships among mites associated with host populations.ResultsIn all the analyses, the genetic differentiation of Sarcoptes mites from wild boars and Japanese serows was observed. Conversely, considerably close genetic relationships were detected between Caniformia-derived and Japanese serow-derived mites. Because the predator–prey interactions between the omnivorous Caniformia and herbivorous Japanese serow are quite limited and epidemiological history shows at least a 10-year lag between the emergence of sarcoptic mange in Japanese serow and that in Caniformia, the transmission of S. scabiei from Caniformia to Japanese serow is highly suspected.ConclusionsThe close genetic relationships among mites beyond Host–taxon relationships and without obvious predator–prey interactions in Caniformia and Japanese serow deviate from previously reported S. scabiei transmission patterns. This type of cryptic relationship of S. scabiei populations may exist in local mammalian communities worldwide and become a risk factor for the conservation of the remnant and fragmented populations of wild mammals.

Gongylonema infection of wild mammals in Japan and Sardinia (Italy).

The gullet worms, classical Gongylonema pulchrum and newly differentiated Gongylonema nepalensis, are prevalent in various mammals in Japan and Sardinia, Italy, respectively. The former species is cosmopolitan in distribution, dwelling in the mucosa of the upper digestive tract of a variety of domestic and wild mammals, and also humans. At present, the geographical distribution of G. nepalensis is known in Nepal and Sardinia, with the nematode having been recorded from the oesophagus of water buffaloes (Nepal), cattle, sheep, goats and wild mouflon (Sardinia). To clarify their natural transmission cycles among domestic and wild mammals, the present study analysed the ribosomal RNA gene (rDNA) and mitochondrial cytochrome c oxidase subunit 1 gene (cox1) of worms of various origins: G. pulchrum worms from sika deer, wild boars, Japanese macaques, and feral alien Reeves's muntjacs in Japan, and G. nepalensis worms from a red fox and a wild boar in Sardinia. Although the internal transcribed spacer (ITS) regions of rDNA and partial cox1 nucleotide sequences of G. pulchrum from native wild mammals in Japan were distinct from those of the worms in cattle, the worms from feral alien Reeves's muntjacs showed the cattle-type ITS genotype and cox1 cattle-I and II haplotypes. The rDNA and cox1 nucleotide sequences of G. nepalensis from a red fox in Sardinia were almost identical to those of the worms from domestic and wild ruminants on the island. The ecological interaction between domestic and wild mammals and their susceptibility to different Gongylonema spp. must be considered when trying to elucidate this spirurid's transmission dynamics in nature.

自然環境としてのわが国の大型野生動物 : ニホンツキノワグマとニホンイノシシ : 「森林と国土論 : 地理学からのアプローチ」 : 昭和62年度秋季学術大会シンポジウム

自然環境としてのわが国の大型野生動物 : ニホンツキノワグマとニホンイノシシ : 「森林と国土論 : 地理学からのアプローチ」 : 昭和62年度秋季学術大会シンポジウム

Local-scale genetic structure in the Japanese wild boar (Sus scrofa leucomystax): insights from autosomal microsatellites

The Japanese wild boar (Sus scrofa leucomystax) is one of the most widely distributed mammals in Japan. However, its population structure and pattern of gene flow at a regional level are poorly understood. In this study, we investigated the local-scale genetic structure of the Japanese wild boar. In total, 172 individuals sampled in Gifu Prefecture, central Japan, were genotyped for 29 autosomal microsatellite loci. Significant genetic differentiations (F ST = 0.020–0.128) were detected among some geographical areas. In addition, in the overall population (n = 172), all loci deviating from the Hardy–Weinberg equilibrium exhibited a significant deficit of heterozygotes. These results suggest the presence of genetic substructuring in the local population. Moreover, Bayesian cluster analysis revealed the presence of substructuring within the population, despite the relatively small study area (10,621 km2). Spatial Bayesian cluster analysis showed that the boundaries of subpopulations were generally consistent with landscape features (e.g. main rivers, urban areas and road and train networks). Our study implies that these landscape features play a significant role as a barrier to dispersal and gene flow in the local population of the Japanese wild boar.

Intraspecific and interspecific genetic variation of Gongylonema pulchrum and two rodent Gongylonema spp. (G. aegypti and G. neoplasticum), with the proposal of G. nepalensis n. sp. for the isolate in water buffaloes from Nepal.

The gullet worm (Gongylonema pulchrum) has been recorded from a variety of mammals worldwide. In an earlier study, we demonstrated two separate transmission cycles in cattle (Bos taurus) and wild mammals in Japan based on nucleotide sequences of the ribosomal RNA gene (rDNA) and cytochrome c oxidase subunit I (cox-1) region of mitochondrial DNA of multiple isolates of different origins. Our earlier study additionally demonstrated two major cox-1 haplotypes of G. pulchrum prevalent in cattle in Japan. In the present study, we collected G. pulchrum from cattle and goats (Capra hircus) in Alashan League, Inner Mongolia, China; Gongylonema aegypti from spiny mice (Acomys dimidiatus) in the Sinai Peninsula, Egypt; and Gongylonema neoplasticum from a black rat (Rattus rattus) in Okinawa Island, Japan, to analyze their genetic relationships with G. pulchrum in Japan. The gullet worms from Alashan League had almost identical rDNA nucleotide sequences and two cox-1 haplotypes as seen in G. pulchrum from the cattle in Japan. The two rodent Gongylonema spp. had distinct rDNA nucleotide sequences compared with those of G. pulchrum; only the 18S and 5.8S rDNA sequences showed high identities at 97.2-98.7%, while the remaining sequences were less than 75% identical. The 18S, 5.8S, and 28S rDNA sequences of the two rodent Gongylonema spp. showed nucleotide identities of 99.8% (1811/1814), 100% (158/158), and 98.9% (3550/3590), respectively. The cox-1 regions showed 91.6% (338/369)-92.1% (340/369) identities, with completely identical amino acid sequences. The genetic diversities of three distinct Gongylonema spp. and their possible intraspecific genetic variation may allow us to resolve the taxonomic position of Gongylonema spp. which display few obvious morphological differences from their congeners. Consequently, the Gongylonema isolate from water buffaloes (Bubalus bubalis) in Nepal reported in our previous study is concluded to be a new species, and Gongylonema nepalensis n. sp. is erected for it.

Beyond dichotomy in the protection and management of marine mammals in Japan

Introduction: Marine mammals are natural resources for humans. They are also considered as pests in some fisheries. Damage to fisheries by Steller sea lions in northern Japan has increased since the 1990s. The major factor that drives the relationship between humans and marine mammals has changed from the middle of the 20 th century to the early 21 st century; this is the result of changes in the extent to which their populations are threatened, the demand for these natural resources, and policies for marine mammal conservation. Methods: In this paper, we have chosen four major taxa of marine mammals to investigate changes in policies for marine mammals in Japan: Steller sea lions, harbor seals, dugong and cetaceans. Some cetacean species have been overexploited in the past and remain threatened. Their full recovery is still awaited. Other large cetacean species have never been threatened; nevertheless all commercial whaling was placed under a moratorium by the International Whaling Commission in 1982. Results: Japan still catches small cetaceans in coastal whaling operations and large cetaceans for scientific research. Except for cetaceans, the policy for marine mammals has changed from resource use in the middle of the 20 th century, to protection in the late 20 th century, and to nuisance control since 2014. Environmental groups played an important role in building consensus for these policy changes. Discussion and conclutions: We seek a comprehensive policy that achieves a balanced approach to accommodate three different roles of marine mammals: a natural resource, participants in marine ecosystems and agents of damage to fisheries. We also discuss the importance of stakeholder involvement in changing policies for wildlife management, ranging from complete protection to population control. Key words: Adaptive wildlife management; japanese commercial whaling; dugong, Harbor seals; population control; stakeholder involvement; steller sea lion.

Conservation and management of terrestrial mammals in Japan: its system and practices

Discussion and Conclusions: The proportion of natural forests was reduced to about 40 % of the total area of forests by 2013. The most influential laws for wildlife conservation and management in Japan are the “Act on the Conservation of Endangered Species of Wild Fauna and Flora” and “Wildlife Protection and Proper Hunting Act”. The Amami rabbit (Pentalagus furnessi), the Bonin flying fox ( Pteropus pselaphon), a subspecies of Ryukyu flying fox ( Pteropus dasymallus daitoensis), and two subspecies of the leopard cat (Prionailurus bengalensis iriomotensis and P. b. euptilurus) are conserved under the “Act on Conservation of Endangered Species of Wild Fauna and Flora”, whereas the conservation of many endemic terrestrial species that are ranked high in conservation status are not implemented in Japanese laws. Recently many management practices have been developed for overabundant populations of the sika deer (Cervus nippon) and the wild boar (Sus scrofa) under “Wildlife Protection and Proper Hunting Act”.

Involvement of two genetic lineages of Sarcoptes scabiei mites in a local mange epizootic of wild mammals in Japan.

Similar to wild mammals on the continents, mange caused by the mange mite, Sarcoptes scabiei (Acari: Sarcoptidae) is spreading in wild mammals in most of Japan. We collected crusted or alopetic skin from 120 raccoon dogs (Nyctereutes procyonoides viverrinus), three raccoons (Procyon lotor), six Japanese badgers (Meles anakuma), one Japanese marten (Martes melampus), one stray dog (Canis lupus familiaris), four wild boars (Sus scrofa leucomystax), and one Japanese serow (Capricornis crispus), mainly in an area where mangy wild animals have been increasingly noted in the past 4 yr. The second internal transcribed spacer (ITS2) region of the ribosomal RNA gene and the partial 16S and cytochrome c oxidase subunit I (cox-1) genes of mitochondrial DNA (mtDNA) were characterized in these skin samples. The ITS2 sequencing (404 base pairs [bp]) identified the causative mite for mangy skin lesions of 128 animals as S. scabiei, regardless of host origin. The cat mite (Notoedres cati) was the cause in one raccoon dog and one raccoon. Most mites had almost identical ITS2 nucleotide sequences to those recorded in a variety of mammals worldwide. Partial 16S and cox-1 fragments of mtDNA amplified and sequenced successfully (331 bp and 410 bp, respectively) showed an identical nucleotide sequence except for one site (C vs. T) for the former and four sites (G, C, C, C vs. A, T, T, T, respectively) for the latter fragment. These substitutions were always synchronized, with the two mitochondrial DNA haplotypes (i.e., C/GCCC and T/ATTT) appearing to separately colonize in geographic units. The T/ATTT haplotype fell into a clade where animal-derived mites worldwide dominated, whereas the C/GCCC haplotype formed a geographic branch unique to Japanese isolates. These results suggest that heterologous populations of monospecific S. scabiei are expanding their populations and distributions regardless of host species in an apparently local mange epizootic of wild mammals in Japan.

Need for application of chemical control against invasive mammals in Japan

Need for application of chemical control against invasive mammals in Japan

Range-expanding wildlife: modelling the distribution of large mammals in Japan, with management implications

The spatial distribution of large mammals has been increasing in industrial nations, often leading to conflicts with humans and significant alteration of natural ecosystems. Species distribution models (SDMs) of the sika deer, Japanese serow, wild boar, Japanese macaque and Asiatic black bear in Japan were constructed to identify the important factors for habitat management. We also projected two scenarios of their future range expansions under a scenario of no change in the variables, and one where the variables change according to a time series. Modelling showed that all species preferred forest and forest/agricultural ecotones. In the best models of the sika deer and wild boar, grasslands (GRASSs) were an important positive factor, while human population density and hunting pressures were negative factors. High human population density was also a negative factor with the Japanese serow and Asiatic black bear. Key environments for the distribution and expansion of large mammals were agricultural areas near forest and GRASSs. Therefore, limiting the access of large mammals to such habitats may contribute to wildlife management. In both scenarios, our projections suggest that the distributions of all species could expand by 2028, resulting in more conflict with humans and significant alterations to natural ecosystems in the future. In order to stop this damaging expansion, habitat management and landscape redesign are important. However, a SDM and future projection include uncertainty. It is necessary to validate the estimates and projections by monitoring the future changes in distribution.

Support system for surveying moving wild animals in the snow using aerial remote-sensing images

Japan is one of the most diverse zoogeographic regions in the world. It includes subtropical to cool temperate zones, high land and low land, and a high ratio of forest and mountain or hill. Owing to their low densities, large geographical ranges, and the large size of forested and mountainous areas, population size information on large mammals in Japan is generally insufficient. To address this problem, we developed an automated support system for detecting wild animals moving over snow using two overlapping aerial images. The system reduces the number of man-hours required to survey moving wild animals from a large amount of aerial image data. The system consists of three newly developed algorithms which perform the following tasks: (1) feature point extraction for registering two images, (2) corresponding point identification by determining the correspondence between feature points, and (3) automatic detection of moving wild animals by comparing two images using a computer-aided detection of moving wild animals (DWA) algorithm. We applied the proposed algorithms to several types of aerial images to automatically extract cattle, deer, and a walking human. Furthermore, we conducted a survey of wild animals using the system and used it to detect a walking human. The number of man-hours required to conduct the survey was reduced by 90%. A further advantage of the system was that, since relief displacement effects do not cause false detection, the system can be employed in forested areas during the leaf-off period.

"Invasive Alien Mammals in Japan: Biology of Control Strategy and Conservation", edited by Yamada, F., Ikeda, T., and Ogura, G. / "Biological and Human Dimensions of Species Invasions", edited by Nishikawa, U. and Miyashita, T.

"Invasive Alien Mammals in Japan: Biology of Control Strategy and Conservation", edited by Yamada, F., Ikeda, T., and Ogura, G. / "Biological and Human Dimensions of Species Invasions", edited by Nishikawa, U. and Miyashita, T.

Species-specific differences in the accumulation features of organohalogen contaminants and their metabolites in the blood of Japanese terrestrial mammals

Residue levels and patterns of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), their hydroxylated metabolites (OH-PCBs, OH-PBDEs), and methoxylated PBDEs (MeO-PBDEs) in the blood of various terrestrial mammals in Japan, including cats, raccoon dogs, dogs, masked palm civets, foxes, raccoons, badgers, and mongooses were determined. Tri- through penta-chlorinated OH-PCBs were predominant in cat blood, whereas hexa- through octa-chlorinated OH-PCBs were found in other species. High proportion of BDE209 was found in all species, suggesting exposure to municipal waste and soil containing higher levels of deca-BDE products. 6OH-/MeO-BDE47 and 2′OH-/MeO-BDE68 were dominant in all terrestrial mammals. This is first report on the detection of OH-/MeO-PBDEs in the blood of terrestrial mammals. High concentrations of OH-/MeO-PBDEs were found in cats, suggesting the intake of these compounds from seafood. Cats exhibited higher accumulation and specific patterns of OH-PCBs, OH-PBDEs, and MeO-PBDEs, they may be at a high risk from these metabolites.