Search Results (65)

The State of Alaska, USA, has a long and controversial history of controlling predators to enhance ungulate populations, including moose (Alces alces). Moose management is complicated by a dual system in which the Federal and State governments prioritize harvesting moose for human consumption over other considerations, such as trophy or sport hunting, but have conflicting regulations regarding who is eligible to harvest moose. Wildlife management for the State is overseen by the Alaska Board of Game (BOG), with advice from the Alaska Department of Fish and Game (ADFG). In accordance with its Intensive Management Policy, the BOG establishes regulations promoting the harvest of moose and other ungulates for human consumption. This typically occurs by controlling bears (Ursus americanus and U. arctos) and gray wolves (Canis lupus) in anticipation of increasing ungulate harvests, often without adequate information on the status and ecology of predator or ungulate populations. We provide a narrative and integrative review of moose population dynamics to help resolve those issues. We argue that the current management of moose and their predators in Alaska does not encompass a full range of management options and fails to consider or implement important aspects of their population dynamics. Predators maintain some moose populations at a low density, reducing the harvest of moose but promoting large-antlered individuals, which are of value to Alaska’s professional guide and tourism industries. Using modern models of population dynamics of moose and other ungulates, we argue that if the proximity of the moose population to K (the ecological carrying capacity) is known, management strategies that increase the human harvest of moose and also promote large-antlered trophies are not mutually exclusive. We list life history and population characteristics to help determine the nutritional status of moose populations in relation to K, thereby guiding wise management of that valuable resource. We also recommend an adaptive management approach to assessing the effects of such activities. We caution, however, that to wisely manage these important wildlife resources, more information on the dynamics of moose and their predators is necessary. A system that embraces more biology and fewer politics would provide greater opportunities to employ the best science in the management of moose and their predators. Full article

The brown bear (Ursus arctos) occurs across several regions of Türkiye and occasionally damages beehives near rural settlements. This study examines temporal data and the spatial arrangement of beehive damage incidents recorded in the Ilgaz district of Çankırı, Türkiye during 2023–2024. The temporal data were evaluated across lunar phases. A chi-square test showed that incidents did not distribute evenly. A higher frequency was found during the Waxing Crescent phase. Spatial intensity was mapped using Kernel Density Estimation (KDE), where bandwidth selection followed a cross-validation procedure. KDE results showed clear concentrations of incidents in the southern and southwestern parts of the district, while other areas recorded few or none. A Decision Tree (DT) classifier based on eleven environmental variables was used to identify predictors of incident presence. The DT achieved an AUC of 0.808. It identified “distance to settlement” as the primary separating variable, followed by “distance to road”, “distance to forest”, and the “Human Footprint Index”. Beehive damage followed a non-random temporal pattern across lunar phases. It clustered near settlements. Conflict timing followed both environmental conditions and human activity. The findings provide an empirical basis for reducing apiary losses and improving coexistence measures between local communities and brown bears in the Ilgaz region. Full article

Human–wildlife conflicts can be broadly categorized from the perspective of human activities into conflicts (a) caused by the expansion of human activities into wildlife habitats, and (b) resulting from the re-expansion of wildlife habitats due to the decline of human activities. The first type of conflict has been managed through the systematic training of wildlife managers, field specialists, and well-organized institutional frameworks. In Japan, Asiatic black bears (Ursus thibetanus) and brown bears (Ursus arctos) have increasingly come into human contact because of habitat re-expansion. Short-term measures to protect human life and property include the implementation of the 2024 and 2025 revisions of the Wildlife Protection and Hunting Management Act, which designated bears as “managed wildlife” and “dangerous wildlife” and permitted emergency culling in residential areas. However, Japan’s approach remains limited in scope and depth, relies on ad hoc responses by local hunters, and lacks adequate public education and effective long-term sustainability planning. This study highlights the necessity of a multi-layered policy framework that integrates human–wildlife conflict management, particularly human–bear conflict, by comparing U.S. laws and policies and incorporating them into medium- and long-term strategies for community resilience and national land conservation. This approach may serve as a model for countries and regions facing similar demographic and ecological challenges. Full article

Long-term spaceflight induces multisystem stress, including cardiovascular deconditioning, skeletal muscle atrophy, immune suppression, and neuro-ocular syndromes. Current countermeasures reduce symptoms but cannot replicate the synergistic resilience needed for extended missions or critical illness. Hibernating animals, specifically brown bears (Ursus arctos), survive prolonged immobility, starvation, and bradycardia without resultant pathology. This review incorporates adaptations observed in bears and certain torpid species, including reversible insulin resistance, suppression of muscle atrophy genes MuRF1 and Atrogin-1, and maintenance of the heart despite seasonal production decline. The thirteen-lined ground squirrels (Ictidomys tridecemlineatus) maintain retinal structure and synaptic stability throughout torpor, avoiding neuro-ocular complications despite prolonged inactivity. Mechanisms span from RBM3-dependent synaptic maintenance, titin isoform remodeling under the control of RBM20, mTOR and FOXO pathway regulation, remodeled hydrogen sulfide metabolism, and microbiome-mediated nitrogen salvage. These adaptations are different from human adaptation to microgravity and disuse and offer translational candidates for synthetic torpor, probiotic engineering, neuroprotection, and protein-sparing therapy. Hibernators are not passive stress subjects; they perform coordinated anticipatory responses in multiple organs. Comparing these systems in large and small hibernators, we aim to uncover a biologically realistic path to human resilience. These findings guide a shift from reactive, pharmacological measures for preserving human health during space flight, intensive care, and extreme environments towards proactive, biologically initiated measures. Full article

Assessing the well-being of captive brown bears is essential for responsible species management and meeting European and national animal care standards outside their natural habitats. The present study aims to assess the welfare of captive brown bears in Bulgaria, considering environmental parameters, husbandry procedures, and the psychological and physical condition of the animals. The study was conducted on 28 brown bears in 11 zoos in Bulgaria and 19 bears in Bear Sanctuary Belitsa. A specific questionnaire and interviews were conducted with zoo managers and keepers. The welfare of the bears was evaluated based on their living conditions, husbandry, and physical and psychological well-being. The Nature and Animal Protection Center in Dobrich received the highest rating for the welfare of two brown bears among the zoos in the study. The study identified annual veterinary check-ups and enrichment programmes as areas needing improvement. Full article

Habitat fragmentation restricts the movement of large mammals across broad landscapes, leading to isolation of individuals or groups, reduced interaction with other species, and limited access to vital resources in surrounding habitats. In this study, we aimed to determine the wildlife ecological corridors for five large mammals (Ursus arctos, Cervus elaphus, Capreolus capreolus, Sus scrofa, and Canis lupus) between Kastamonu Ilgaz Mountain Wildlife Refuge and Gavurdağı Wildlife Refuge. In the field studies, we used the transect, indirect observation, and camera-trap methods to collect presence data. Maximum Entropy (MaxEnt) (v. 3.4.1) software was used to create habitat suitability models of the target species, which are based on the presence-only data approach. The results indicated that AUC values varied between 0.808 and 0.835, with water sources, stand type, and slope contributing most significantly to model performance. In order to determine wildlife ecological corridors, resistance surface maps were created using the species distribution models (SDMs), and bottleneck areas were determined. The Circuit Theory approach was used to model the connections between ecological corridors. As a result of this study, we developed connectivity models for five large mammals based on Circuit Theory, identified priority wildlife ecological corridors, and evaluated critical connection points between two protected areas, Ilgaz Mountain Wildlife Refuge and Gavurdağı Wildlife Refuge. These findings highlight the essential role of ecological corridors in sustaining landscape-level connectivity and supporting the long-term conservation of wide-ranging species. Full article

In June 2025, a two-year-old female brown bear (Ursus arctos) appeared in the streets of Vilnius, the capital city of Lithuania. This sparked significant public, institutional, and media responses. This paper analyzes the event through ecological, social, and symbolic lenses to explore how large carnivores are perceived and managed at the wildland–urban interface. Through an examination of media reports, policy responses, and theoretical perspectives from environmental sociology and narrative studies, we explore how the bear’s presence became a public safety concern and a culturally significant symbol. Public discourse revealed tensions between institutional authority and local ethical values, as evidenced by hunters’ refusal to carry out a kill permit. This case also illustrates the growing use of technology, such as drones, in urban wildlife management. The bear’s peaceful departure reinforced the effectiveness of nonlethal conflict resolution. This case underscores the importance of integrating ecological realities with social perceptions, media framing, and symbolic interpretations in large carnivore conservation. It emphasizes the need for interdisciplinary approaches that address the emotional and cultural aspects of human–wildlife interactions in rapidly urbanizing areas. Full article

The conservation of small and genetically vulnerable brown bear populations, such as the Cantabrian subpopulation in Spain, depends on developing species-specific assisted reproductive technologies and genetic resource banks. However, the lack of standardized sperm collection and cryopreservation protocols hinders their application. This study provides the first comparative analysis of sperm quality and proteomic profiles from three different origins: epididymal, pre-ejaculated, and ejaculated. Sperm quality parameters —motility and kinetic, viability, apoptosis, and oxidative stress— and protein expression were assessed. Although yields were similar, marked differences were observed in sperm quality and protein profiles. Sixty-three proteins involved in metabolism, stress response, and oxidative balance were differentially expressed depending on sperm origin. Epididymal sperm showed the highest viability and motility, lowest apoptosis, and a proteomic profile indicative of active spermatogenesis and enhanced oxidative stress defense. In contrast, ejaculated sperm had increased oxidative stress and reduced expression of metabolic proteins, while pre-ejaculated sperm exhibited lower motility, likely due to urine contamination and mitochondrial protein alterations, despite comparable viability and apoptosis. These findings offer novel insights into brown bear sperm biology and highlight the importance of sperm origin in developing optimized assisted reproduction strategies, ultimately supporting ex situ conservation efforts for this species. Full article

Activity patterns constitute a critical adaptive trait in large carnivores, enabling them to manage interspecific competition, enhance their foraging efficiency, and adapt to fluctuating environmental conditions. At the community level, elucidating the temporal activity allocation of sympatric large carnivores is essential for understanding species coexistence mechanisms. However, the activity patterns of most large carnivores remain inadequately explored. In this study, spanning a survey period from June 2014 to April 2024, we employed infrared camera technology to collect a total of 3312, 352, 240, and 79 independently validated photographs of snow leopards (Panthera uncia Schreber, 1775), wolves (Canis lupus Linnaeus, 1758), brown bears (Ursus arctos Linnaeus, 1758), and Eurasian lynx (Lynx lynx Linnaeus, 1758), respectively, across six distinct regions in the Sanjiangyuan Region (SR) and during different monitoring time periods. We utilized kernel density estimation and the coefficient of overlaps to assess diel activity pattern overlap and competitive intensities through pairwise comparisons among these four large carnivores. An analysis of the diel activity rhythm curves revealed that all four large carnivores predominantly exhibited nocturnal behavior, although their peak activity periods differed notably. Furthermore, the diel activity rhythm overlap between each pair of species showed moderate to high intensity throughout the year (0.5 ≤ Δ < 1), including during both the cold and warm seasons. Specifically, the diel activity rhythms of snow leopards and wolves, snow leopards and Eurasian lynx, and wolves and Eurasian lynx exhibited high levels of overlap annually and during the cold season (0.8 ≤ Δ < 1) but only moderate overlap during the warm season (0.5 ≤ Δ < 0.8). Our findings suggest that the diel activity rhythms of these four large carnivore species exhibited considerable overlap, potentially intensifying interspecific competition. This study advances our knowledge on the competitive and coexistence mechanisms of large carnivores in high-altitude mountainous ecosystems, offering critical data for their conservation and management. Full article

Background: The illegal trade in wildlife remains a critical threat to biodiversity, prompting the development of international regulatory frameworks such as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). One of the key challenges in enforcement is the detection of CITES-listed species in highly processed consumer goods. Methods: This study investigates the use of molecular techniques to detect animal DNA in two selected commercially available medicinal products—a balm and a gel—marketed with ingredients suggestive of protected species such as the brown bear (Ursus arctos) and the medicinal leech (Hirudo medicinalis). Results: Although DNA from these target species was not detected, the analysis revealed the presence of genetic material from the American mink (Neovison vison) and domestic pig (Sus scrofa), indicating the undeclared use of animal-derived substances. While limited in scope, these findings suggest potential ethical and transparency concerns, particularly for consumers adhering to vegetarian, vegan, or religious dietary practices. Conclusions: The study illustrates the feasibility of applying DNA-based screening methods in complex, degraded matrices and their potential as supportive tools in consumer product assessment. However, broader studies are necessary before drawing general regulatory or conservation conclusions. Full article

In recent years, due to the expansion of cities, the transformation of agricultural areas, the forestry activities carried out solely for wood production, and the spread of transportation networks, natural habitats have become increasingly fragmented, and suitable habitats for wildlife are rapidly decreasing. As a result, natural areas are being divided, connections are being cut off, species’ living spaces are shrinking, and species and habitats are being isolated. This fragmentation significantly hinders the natural movements of large mammals (Ursus arctos, Sus scrofa, and Canis lupus), leading to reduced genetic diversity and threatening the long-term viability of their populations. This research, conducted in the Ballıdağ and Kurtgirmez regions of the Western Black Sea Region of Türkiye, aimed to determine the movement corridors of the brown bear (Ursus arctos), wild boar (Sus scrofa), and wolf (Canis lupus) in the area and to evaluate the habitat connections for these species. This study relied on data obtained through field studies and the previous literature. Ecological modeling was used with the Maximum Entropy Method (MaxEnt) to understand the relationships between these species and environmental variables, and the barriers posed by the latter. Ecological corridor maps were created to evaluate the effects of habitat fragmentation in the region and species’ potential to maintain critical connection points despite this fragmentation using Circuitscape software based on the Circuit Theory approach. As a result of the analysis, it was determined that the AUC values were between 0.75 and 0.8; the most important variables in the models were road density, vegetation, and elevation; focal points and resistance surface areas were determined for three large mammal species; and important ecological corridors were defined between the Ballıdağ and Kurtgirmez regions. This study revealed that preserving habitat connections and reducing fragmentation is critical for the long-term existence of predator species and ecosystem health. Full article

Climate change poses a significant threat to biodiversity. Predicting the impacts of climate change on species distribution and dispersal through computational models and big data analysis can provide valuable insights. These predictions are crucial for developing effective strategies to mitigate the threats that climate change poses to biodiversity. Our study investigated the potential impact of climate change on an umbrella species (Ursus arctos pruinosus) in Western Sichuan Province, China. We employed the MaxEnt and Circuit Theory to assess both the current and potential future shifts in the distribution and migration corridors. The results indicated that climate and environmental factors had the greatest influence on species distribution, with bioclimatic variables bio12, bio3, and elevation contributing 22.1%, 21.5%, and 19.3%, respectively. Under current climatic conditions, the total suitable habitat area for the species was 70,969.78 km², with the largest suitable habitats located in Shiqu and Litang, accounting for 24.39% and 15.86% of the total area, respectively. However, under future climate scenarios, predictions for RCP 2.6, RCP 4.5, and RCP 8.5 showed a significant reduction in suitable habitat area, ranging from 7789.26 km² to 16,678.85 km². The Yajiang and Xinlong counties experienced the most severe habitat reductions, with declines exceeding 50%. Additionally, the altitudinal distribution of suitable habitats shifted, with suitable habitats gradually moving to higher elevations under future climate scenarios. Our study also analyzed the species’ dispersal paths. Under current climatic conditions, the dispersal paths predominantly followed a northwest-to-southeast orientation. However, by the 2070s, under all three RCPs, dispersal resistance is projected to significantly increase, the density of dispersal paths will decrease, and the connectivity of these paths will be reduced. In the most extreme RCP 8.5 scenario, southern dispersal paths nearly disappeared, and the dispersal paths contracted towards the northwest. These findings highlight potential threats posed by climate change to the species’ habitats and dispersal corridors, emphasizing the importance of considering both current and future climate change in conservation strategies to protect this vulnerable species and its ecosystem. Full article

The brown bear (Ursus arctos arctos) is the only bear species on the Romanian territory, its natural habitat occupying a third of the country’s surface, including the entire mountain area as well as the hills in the immediate vicinity. The bear population in Romania is the largest in Europe, increasing every year due to legislative protection, the species being present in Annex II of the Habitats Directive. The fragmentation of the bears’ habitat is the main cause of conflict occurrences between bears and the human population, which have occurred increasingly often in recent years. The main aim of this study is the ecological diagnosis of lands populated with bears in Romania to identify the highest quality habitats within the hunting grounds and to identify possible ecological corridors aimed at preserving the connectivity between them, using GIS spatial analysis techniques and taking into account the ecological conditions needed for the brown bear to survive. Following the spatial modelling of the open-source data, it was possible to observe the presence of habitats of the highest quality that could support a bear population outside the areas where bear specimens are concentrated (the counties of Mureș, Bistrița, Harghita, Covasna, Neamț, Buzau, Vrancea, Prahova, Brașov, Sibiu, and Argeș). The analysis of these habitats, where the bear population has exceeded the optimal level that they can support, highlighted that to allow the passage of bear specimens from one habitat to another, it is necessary to create ecological corridors in several key areas deducted on the basis of mathematical models. Full article

Fecal glucocorticoid metabolites have been used to evaluate responses to stressors in captive adult polar (Ursus maritimus) and grizzly (Ursus arctos horribilis) bears. However, there is a lack of physiological information on juvenile bears in captivity that could help expand the current understanding of their development and welfare. To address these questions, we tracked fecal glucocorticoid metabolites (FGMs) and behavior for 15 months in two polar bear cubs born at the Detroit Zoo, one who was mother-reared (Astra) and one who was hand-reared (Laerke), and one rescued grizzly bear cub (Jeb) reared at the Zoo. To allow access to a social partner during key developmental stages, Laerke and Jeb were housed together for eight months. Daily opportunistic samples were analyzed for fecal cortisol metabolites using an enzyme immunoassay and compared against behavior, social proximity, and environmental data gathered from 15 min focal observations. Based on a combination of generalized linear mixed models and Wilcoxon and Kruskal–Wallis tests, we found no significant variation in mean FGMs between Astra and Laerke, but both had significantly different mean FGMs compared to Jeb. We found that Laerke had higher FGM concentrations when she spent more time engaged in all-occurrence social negative behaviors and lower FGMs when engaged in social positive behaviors. For Jeb, FGMs were lower when in social proximity and higher following separation from Laerke. These data provide novel insights into the physiological states of juvenile bears during key stages and contribute to the growing body of information on polar and grizzly bear development. Full article

Habitat fragmentation poses a significant threat to the existence and reproduction of large carnivores, such as brown bears, as it affects the genetic connectivity of populations and, consequently, their long-term viability. Understanding the genetic makeup and dispersal patterns in areas where brown bears live is crucial for developing effective conservation plans and promoting human-brown bear coexistence. In this study, 214 hair samples were collected non-invasively from brown bears and were genetically analyzed using fifteen specific microsatellite loci to shed light on the genetic status and demography of a sub-population residing in Central Greece (Trikala-Meteora area). The broader Central and South Pindos regions have not been studied for over a decade; however, high levels of genetic diversity, a lack of heterozygosity deficiency, and no signs of inbreeding, along with an estimated effective population size (Ne = 99), confirm the good conservation status of this sub-population. Moreover, the existence of a natural and apparently functional corridor in Central Pindos was demonstrated by bear movements between the western and eastern parts of the project area, enhancing the sustainability of the population. These findings will contribute to future efforts to conserve natural corridors that enable functional connectivity among large areas of brown bear territories in Greece. Full article