Yezo virus (YEZV) is an emerging tick-borne virus that causes acute febrile illness. It has been continuously reported in patients and ticks in Japan and China since its first identification in Hokkaido, Japan. While serological tests have demonstrated that YEZV infections are prevalent in wild animals, such as raccoons (Procyon lotor), the determinants of infection in wild animals remain largely unknown.
View Article and Find Full Text PDFTicks prefer specific feeding sites on a host that are influenced by host–tick and tick–tick interactions. This study focused on the spatiotemporal distribution of ticks in Hokkaido sika deer, an important tick host in Hokkaido, Japan. Tick sampling was performed on the sika deer in the Shiretoko National Park between June and October 2022.
View Article and Find Full Text PDFIn Nepal, the distributions of three bear species vary: sloth bears (Melursus ursinus) in the lowlands, Asiatic black bears (Ursus thibetanus) in the mid-hills, and brown bears (Ursus arctos) in the high Himalayas. We utilized 179 occurrence points for sloth bears, 199 for Asiatic black bears, and 41 points for brown bears to construct a habitat model incorporating climate and topographic variables. Employing various species distribution modeling algorithms in BIOMOD2, the model predicts suitable habitats spanning 10,971.
View Article and Find Full Text PDFRevealing interactions between ticks and wild animals is vital for gaining insights into the dynamics of tick-borne pathogens in the natural environment. We aimed to elucidate the factors that determine tick infestation in wild animals by investigating ticks on invasive raccoons (Procyon lotor) in Hokkaido, Japan. We first examined the composition, intensity, and seasonal variation of ticks infesting raccoons in six study areas in Hokkaido from March 2022 to August 2023.
View Article and Find Full Text PDFHibernating animals undergo a unique and reversible decrease in their whole-body metabolism, which is often accompanied by a suppression of mitochondrial respiration. However, the precise mechanisms underlying these seasonal shifts in mitochondrial metabolism remain unclear. In this study, the effect of the serum from active and hibernating Japanese black bears on mitochondrial respiration was assessed.
View Article and Find Full Text PDFTuberculosis (TB) is an emerging threat to the survival of elephants in Nepal. We investigated the lung tissue samples from nine elephants that died from 2019 to 2022 in Nepal using culture, conventional PCR, and loop-mediated isothermal amplification (LAMP) and then performed genotyping of five PCR-positive isolates to understand the possible transmission dynamics of Mycobacterium tuberculosis (Mtb). Results showed that two-thirds (6/9) of elephants were confirmed to be infected from Mtb by LAMP, 5/9 by PCR, and 4/9 by culture.
View Article and Find Full Text PDFAge is an essential trait for understanding the ecology and management of wildlife. A conventional method of estimating age in wild animals is counting annuli formed in the cementum of teeth. This method has been used in bears despite some disadvantages, such as high invasiveness and the requirement for experienced observers.
View Article and Find Full Text PDFTick-borne diseases have recently been considered a potential emerging public health threat in Malaysia; however, fundamental studies into tick-borne pathogens and microbiome appear limited. In this study, six tick species (, , and ) collected from two primary forests and an oil palm plantation in Sarawak, Malaysian Borneo, were used for microbiome analysis targeting bacterial 16S rDNA using next-generation sequencing (NGS). In addition, bacterial species were further characterized in conventional PCRs to identify potential pathogens.
View Article and Find Full Text PDFHibernating animals exhibit an unexplained physiological characteristic of skeletal muscles being atrophy resistance, in which case muscle mass and strength remain almost unchanged both before and after hibernation. In this study, we examined the alterations in the regulatory systems of protein and energy metabolism in the skeletal muscles of Asiatic black bears during hibernation. Skeletal muscle samples (vastus lateralis muscle) were collected from identical individuals (n = 8) during the active (July) and hibernating (February) periods, while histochemical and biochemical analyses were performed.
View Article and Find Full Text PDFIn this study, Babesia screening was conducted in 55 rodents and 160 tick samples collected from primary forests and an oil palm plantation in Sarawak, Malaysian Borneo. PCR targeting the 18S ribosomal DNA revealed the presence of Babesia spp. DNA detected in two questing male Haemaphysalis shimoga ticks collected from the oil palm plantation.
View Article and Find Full Text PDFRobust estimates of demographic parameters are critical for effective wildlife conservation and management but are difficult to obtain for elusive species. We estimated the breeding and adult population sizes, as well as the minimum population size, in a high-density brown bear population on the Shiretoko Peninsula, in Hokkaido, Japan, using DNA-based pedigree reconstruction. A total of 1288 individuals, collected in and around the Shiretoko Peninsula between 1998 and 2020, were genotyped at 21 microsatellite loci.
View Article and Find Full Text PDFWe distributed anthelmintic baits on a university campus in Japan inhabited by foxes infected with Echinococcus multilocularis to design an effective baiting protocol for small public areas. High-density baiting can reduce the risk for human exposure to the parasite to near zero. However, monthly baiting is recommended to maintain this effect.
View Article and Find Full Text PDFMammals exhibit several types of diel activity pattern, including nocturnal, diurnal, crepuscular, and cathemeral. These patterns vary inter- and intra-specifically and are affected by environmental factors, individual status, and interactions with other individuals or species. Determining the factors that shape diel activity patterns is challenging but essential for understanding the behavioral ecology of animal species, and for wildlife conservation and management.
View Article and Find Full Text PDFMammals have experienced a massive decline in their populations and geographic ranges worldwide. The sloth bear, (Shaw, 1791), is one of many species facing conservation threats. Despite being endangered in Nepal, decades of inattention to the situation have hindered their conservation and management.
View Article and Find Full Text PDFHibernating bears remain in their dens for 5-7 months during winter and survive without eating or drinking while staying inactive. However, they maintain their physical functions with minimal skeletal muscle atrophy and metabolic dysfunction. In bears, resistance to skeletal muscle atrophy during hibernation is likely mediated by seasonally altered systemic factors that are independent of neuromuscular activity.
View Article and Find Full Text PDFIn the Japanese macaque, semen has been collected by electro-ejaculation (EE), using the higher voltage stimuli compared to other species including genus Macaca. Semen coagulates immediately after ejaculation, which makes difficult to produce high-quality semen for artificial insemination. Recently, semen collection using urethral catheterization (UC) has been reported in carnivore and this technique may allow semen collection without coagulation in a less invasive manner.
View Article and Find Full Text PDFBody condition in mammals fluctuates depending on energy intake and expenditure. For brown bears (), high-protein foods facilitate efficient mass gain, while lipids and carbohydrates play important roles in adjusting dietary protein content to optimal levels to maximize energy intake. On the Shiretoko Peninsula, Hokkaido, Japan, brown bears have seasonal access to high-lipid pine nuts and high-protein salmon.
View Article and Find Full Text PDFPiroplasms, which include spp. and spp., are protozoan parasites carried by ticks and commonly cause disease in animals and humans.
View Article and Find Full Text PDFHibernating bears survive up to 6 months without feeding while yet maintaining metabolic homeostasis. We previously reported expression changes in energy metabolism-related genes in the liver of hibernating Japanese black bears. The present study examined the role of microRNAs in the regulation of hepatic gene expression during hibernation.
View Article and Find Full Text PDFIn Japan, there are concerns that invasive alien raccoons prey on rare native species during their spawning season from late winter to early summer. We investigated raccoon predation impact by examining the predation presence using DNA metabarcoding and extent of predation on rare native species using stable isotope analysis. We captured raccoons in Hokkaido, Japan from April to August in 2018 and 2019.
View Article and Find Full Text PDFThe tick Amblyomma testudinarium Koch, 1844 (Acari: Ixodidae) is known as a vector of several pathogens such as Rickettsia tamurae and severe fever with thrombocytopenia syndrome (SFTS) virus. This tick species is present in many Asian countries, including Japan, where its distribution is limited to the warm areas of Kanto region and the southwestern region. The present study reports the recovery of a partially engorged A.
View Article and Find Full Text PDFMembers of the sensu lato (Bbsl) complex are etiological agents of Lyme disease (LD), and is one of the relapsing fever (RFB). Despite the serological evidence of LD in Malaysia, there has been no report from Sarawak, Malaysian Borneo. Thus, this study aimed to detect and characterize in rodents and ticks from primary forests and an oil palm (OP) plantation in Sarawak.
View Article and Find Full Text PDFHuman habituation of large carnivores is becoming a serious problem that generates human-wildlife conflict, which often results in the removal of animals as nuisances. Although never tested, human habituation potentially reduces the fitness of adult females by reducing their offspring's survival as well as their own, due to an increased likelihood of human-caused mortality. Here, we tested this hypothesis in brown bears inhabiting Shiretoko National Park, Japan.
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