1. The biology and natural histroy of Meles amurensis inhabiting the Korean Peninsula was comprehensively reviewed in terms of taxonomy, morphology, ecology, genetics, conservation, and management in terms of taxonomy, morphology, ecology, genetics, ...
1. The biology and natural histroy of Meles amurensis inhabiting the Korean Peninsula was comprehensively reviewed in terms of taxonomy, morphology, ecology, genetics, conservation, and management in terms of taxonomy, morphology, ecology, genetics, and conservation and management. Meles amurensis is a medium-sized mustelid distributed broadly across the Northeastern Asia, including the Korean Peninsula. Although Eurasian badgers were long treated as a single species (M. meles), successive molecular phylogenetic and morphometric studies led to the recognition of M. leucurus and M. anakuma as distinct species. Puzachenko et al. (2025) proposed elevating the Northeastern Asian population of badger to full species rank as M. amurensis, based on cranial morphology demonstrating clear differentiation from M. leucurus. The species is characterized by a stocky body, short limbs, and narrow black facial stripes through the eyes, weighing 4–10 kg. It is distributed throughout the Korean Peninsula including Jeju Island, with core habitats concentrated along the Baekdudaegan mountain range. Reproduction involves embryonic diapause (delayed implantation), with parturition occurring in late winter to early spring. Behavioral ecology is predominantly nocturnal, with peak activity concentrated after sunset. Diet is broadly omnivorous and opportunistic, varying with local prey availability. Ecologically, the species functions as a mesopredator, seed disperser, and ecosystem engineer. Genetic studies indicated a low level of genetic diversity within the Korean population but confirmed the Korean badger as a distinct phylogeographic lineage. Given the combination of habitat loss, road mortality, historical overharvesting, and the recent reclassification of the taxon, an independent conservation status assessment and species-specific management plan are urgently warranted.
2. Medium and large mammals on the Korean Peninsula are experiencing habitat loss and fragmentation under the compounding pressures of climate change and land-use transformation. This study quantified the current potential habitat distribution of Meles amurensis and identified the key environmental determinants of its habitat suitability using an ensemble SDM framework. Occurrence records collected from 2021 to 2025 through the National Institute of Biological Resources, National Institute of Ecology, and GBIF were integrated with 17 environmental predictor variables (VIF 〈 7) encompassing WorldClim 2.1 bioclimatic variables, topographic indices derived from a digital elevation model (DEM), the Human Footprint Index (HFI), forest structural attributes, and soil depth. Using the biomod2 package in R, a weighted mean ensemble model (EMwmean) was constructed by combining eight algorithms—GAM, GLM, MARS, ANN, GBM, RF, CTA, and FDA—and evaluated through 10-fold cross-validation. The ensemble model achieved an AUC of 0.925 and a TSS of 0.678, demonstrating high predictive performance. Among individual algorithms, Random Forest attained the highest AUC (0.935) but exhibited evidence of overfitting, as indicated by a calibration AUC of 1.000. Applying the TSS-optimized threshold of 0.527, the total potential suitable habitat was estimated at approximately 48,700 km², representing 48.53% of the study area.Variable importance analysis consistently identified the Human Footprint Index (HFI; 20.3%) and distance to forest (dist_forest; 18.4%) as the dominant predictors across all algorithms, followed by isothermality (BIO3; 7.4%), soil depth (6.2%), and maximum temperature of the warmest month (BIO5; 6.5%). Response curve analysis revealed a nonlinear threshold response to HFI, with presence probability declining sharply beyond a critical disturbance level, consistent with a nonlinear threshold response. Distance to forest exhibited the highest suitability at 0 m, decreasing steeply with increasing distance from forest edges. These findings indicate that badger distribution is primarily constrained by anthropogenic disturbance avoidance and forest continuity, with climatic stability and burrowing-suitable topographic and edaphic conditions playing complementary roles. The habitat suitability maps generated in this study provide a quantitative basis for prioritizing ecological corridor design and spatially explicit habitat management, while offering a reproducible methodological framework applicable to broader conservation planning for medium-sized mammals facing complex environmental pressures on the Korean Peninsula.
3. This study predicted the spatiotemporal dynamics of potential habitat suitability for Meles amurensis in the Korean Peninsula from the 2020s to the 2100s, using the MaxEnt algorithm in conjunction with five CMIP6 global climate models (GCMs: ACCESS-CM2, BCC-CSM2-MR, GISS-E2-1-G, INM-CM5-0, and MRI-ESM2-0) and four Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5). Nineteen bioclimatic variables from WorldClim 2.1 and SRTM-derived elevation data were used as environmental predictors. Model performance, evaluated through 15-fold cross-validation, was satisfactory, with a mean training AUC of 0.758 and test AUC of 0.745. Variable contribution analysis identified elevation (Elev) as the dominant determinant of habitat suitability (68.84%), with climatic variables including the maximum temperature of the warmest month (Bio5), isothermality (Bio3), and temperature seasonality (Bio4) playing supplementary roles. Under current climate conditions, potentially suitable habitat covered 20.9% of the total analysis area (30,190 grid cells), concentrated along the Baekdudaegan mountain range encompassing the Seoraksan, Odaesan, Sobaeksan, and Jirisan massifs. Across all GCMs and scenarios, a consistent near-term expansion of potential habitat was projected for 2021–2040. However, trajectories diverged markedly from mid-century onward: low-emission pathways (SSP1-2.6) maintained habitat area near current levels, while high-emission scenarios (SSP3-7.0 and SSP5-8.5) showed progressive habitat contraction in the latter half of the century. Substantial inter-model uncertainty was evident; INM-CM5-0 projected habitat increases across all scenarios and periods, whereas BCC-CSM2-MR projected a 74.92% reduction under SSP5-8.5 by the end of the century. Gain–Stable–Loss analyses revealed that even scenarios with limited net change involved considerable spatial redistribution of suitable habitat, underscoring the importance of maintaining habitat connectivity. These findings highlight the role of high-elevation Baekdudaegan zones as potential climate refugia and the need to secure elevational movement corridors linking lowland and highland habitats, providing a scientific basis for climate-adaptive conservation strategies for M. amurensis in the face of ongoing climate change.
4. Despite being an important component of temperate forest ecosystems in Northeast Asia, genome-scale population genetic studies of Meles amurensis have been lacking. In this study, double-digest restriction site-associated DNA sequencing (ddRADseq) was applied to characterize genome-wide single nucleotide polymorphism (SNP) variation in Korean populations of M. amurensis. A total of 67 wild individuals were sequenced. Samples were obtained from wildlife rescue centers, endangered species restoration facilities, and national park authorities throughout South Korea. Following library preparation and sequencing, SNP calling was conducted using the Stacks2 pipeline and subsequently filtered using TASSEL 5.0. A final dataset comprising 5,883 high-quality SNP markers from 53 individuals was retained for downstream analyses. Genetic diversity analyses revealed moderate levels of variation, with mean expected heterozygosity (He = 0.243) and observed heterozygosity (HO = 0.254) showing comparable values. The overall mean inbreeding coefficient (FIS = -0.027) indicated a slight excess of heterozygotes and no evidence of substantial inbreeding. Pairwise FST values among regional populations were generally low to moderate, suggesting limited genetic differentiation across most of the Korean Peninsula. Bayesian clustering analysis implemented in STRUCTURE identified K = 3 as the most likely number of genetic clusters. However, genetic differentiation among regions was weak, and no clearly defined geographic population structure was detected. Most individuals exhibited varying degrees of admixture, with particularly pronounced admixture observed in northern Gyeongsangbuk-do. These patterns suggest ongoing gene flow among populations across the Korean Peninsula, while also indicating that geographic features such as the Baekdudaegan mountain range may have partially influenced historical dispersal and connectivity. The present study provides the first genome-wide assessment of genetic diversity and population structure in Korean M. amurensis and establishes an important baseline for future conservation planning, long-term genetic monitoring, and landscape genetic research.
5. Wildlife laundering—the practice of disguising illegally captured wild animals as legally captive-bred individuals through established breeding and trade systems—is increasingly recognized as a major challenge to wildlife conservation and regulatory enforcement worldwide. This study examined institutional vulnerabilities associated with wildlife laundering in South Korea using three representative case studies: the Asiatic black bear (Ursus thibetanus), wild boar (Sus scrofa), and Amur badger (Meles amurensis). Across all three cases, common structural characteristics were identified, including government- supported wildlife farming policies, document-based administrative management systems, and the absence of scientific methods for verifying the origin of individual animals. To evaluate the genetic characteristics of farmed badgers, ddRADseq-based SNP analyses were conducted on a total of 77 individuals, including 10 captive individuals from commercial farms and 67 wild individuals collected throughout South Korea. Following quality filtering, 5,883 high-quality SNP markers from 61 individuals were retained for subsequent analyses. STRUCTURE and principal coordinates analyses (PCoA) showed that captive individuals did not form a genetically distinct cluster separate from wild populations. Likewise, no substantial differences in genetic diversity or overall population structure were detected between captive and wild groups, indicating a high degree of genetic similarity. Under long-term closed breeding conditions, captive populations are generally expected to exhibit measurable genetic differentiation resulting from founder effects, genetic drift, and inbreeding. The absence of such patterns in the present study suggests several non-exclusive explanations, including the relatively recent establishment of the captive population, the use of numerous wild founders during the early development of the farming industry, or continued gene flow between captive and wild populations. Although these findings do not constitute direct evidence of wildlife laundering, they demonstrate that clear genetic boundaries between captive and wild badger populations are currently lacking. The results further suggest that document-based administrative systems alone may be insufficient for objectively verifying the biological origin of captive individuals. The development of SNP-based reference databases, combined with genetic forensic approaches for origin assignment and traceability, would provide a valuable scientific framework for improving wildlife management, monitoring captive breeding systems, and supporting future investigations of illegal wildlife trade and wildlife laundering in South Korea.
6. By integrating the overall findings, this study demonstrated that populations of Meles amurensis on the Korean Peninsula are exposed to multiple threats, including habitat loss and fragmentation driven by climate change, as well as genetic risks associated with illegal capture, wildlife trade, and captive breeding systems. Based on these findings, an integrated conservation and management strategy is proposed. The increasing occurrence of badger in urban areas, particularly in the Seoul metropolitan region, together with associated human injury incidents, has placed the species in the dual role as both a conservation concern and a target of conflict management. We reviewed limitations of the current legal framework under the Wildlife Protection and Management Act and discussed the need for population monitoring, non-lethal mitigation measures, and evidence-based management strategies. SNP marker-based genetic forensic approaches demonstrated the potential for monitoring illegal wildlife trade and tracing population structure, supporting the establishment of a national genetic reference database. Climate change projections identified high-elevation areas along the Baekdudaegan mountain range as potential future climate refugia, emphasizing the importance of maintaining elevational movement corridors and conserving mature forest ecosystems. Given the ecological role of M. amurensis as an ecosystem engineer, conservation outcomes may be further strengthened through the integration of long-term scientific monitoring and citizen science participation. Despite these limitations, this study provides the first comprehensive framework integrating taxonomy, ecology, species distribution modeling, population genetics, wildlife forensics, and conservation management for Meles amurensis in South Korea.