Modeling climate change impacts on the distribution of an endangered brown bear population in its critical habitat in Iran

Climate change impacts on altitudinal movements of society large mammals in the Alborz

This study examines the impact of climate change on the altitudinal movement patterns and number of individuals of four large mammal species within the Central Alborz Protected Area (CAPA) region of the Alborz Mountains, a biodiversity hotspot, over a 23-year period (1999 to 2022). During the warm season (May 25-September 29), temperatures were reported to have increased by 2-2.5 °C, while relative humidity was observed to have decreased by 4-4.5%. Compared to the past two decades (2000-2022), Caspian red deer were observed to initiate their annual high-altitude migrations 15-20 days earlier, with the number of individuals in the summer range increasing more than threefold. Wild goats also migrated earlier, with peak arrivals increasing from 20-36 (1999-2003) to 36-57 (2018-2022) between May 25 and May 31, highlighting temperature as the primary driver of herbivore movement. In contrast, brown bears exhibited more subtle altitudinal movement, likely influenced by both temperature and humidity. Wild boars, with an approximate 40% increase in the number of individuals, tended to return to lower elevations earlier than in previous years (1999-2003). These patterns highlight the role of climate as a significant regulator of movement ecology, influencing high-altitude habitat use. However, human-induced barriers, such as roads and settlements, present additional threats to these seasonal migrations. This underscores the urgent need for adaptive management strategies, including the protection of movement corridors, the expansion of core zones, and enhanced community engagement, to support the resilience of these species under changing climatic conditions.

Impacts of Climate-Land Dynamics on Global Population and Sub-Populations of a Desert Equid

Climate change and escalating land-use transformations pose a significant threat to global biodiversity by disrupting natural habitats. The Asiatic wild ass (Equus hemionus), a near-threatened species, faces various pressures across its Asian range. This study employs a niche modeling approach to assess suitable habitats for the Asiatic wild ass at both the global population and sub-population levels. The analysis integrates the impacts of climate scenarios and land use change across three temporal periods: past, present, and future. To investigate the uncertainty of climate models for the Asiatic wild ass habitat, we used two climate models, CMIP5 and CMIP6, at both global and sub-population levels. Niche overlap models were developed to examine patterns of niche similarity among sub-populations. The results demonstrate a severe decline in both suitable habitat area and the number of viable patches for all sub-populations. Projections reveal that the Mongolian wild ass and Indian wild ass endure the highest levels of isolation and habitat loss, alongside the extinct Syrian wild ass. Sub-population models often predict larger distributions compared to global population models using the same inputs. The outputs of the models indicate a severe decline in suitable habitat, underscoring the necessity of accounting for both ecological and conservation perspectives to understand species distribution dynamics. Our study highlights the need to consider both global population and sub-population levels in climate change assessments. These models provide essential guidance for conservation strategies by identifying suitable habitats and sites for reintroduction. Identifying habitat patches as refuges for large herbivores amidst land-use changes and climate fluctuations is crucial. Incorporating these patches into conservation planning is imperative for preserving biodiversity.

Climate-Driven Range Shifts and Conservation Challenges for Brown Bears in Türkiye

Understanding the current and future distribution of wildlife species is crucial for effective conservation planning, particularly in the face of climate change and increasing anthropogenic pressures. This study aims to assess the potential distribution of brown bears across Türkiye both presently, by 2050 and 2070, considering various climate change scenarios, evaluating habitat vulnerability, and reassessing the effectiveness of protected areas. Using an ensemble forecasting approach, we modeled brown bears' current and future habitat suitability, incorporating 608 occurrence records along with bioclimatic, topographic, and anthropogenic predictors under climate scenarios. Our model estimates that approximately 17.3% of Türkiye (135,556 km2) currently offers suitable habitat for brown bears with the highest suitability found in the Euro-Siberian (46%), Irano-Turanian (43%), and Mediterranean (11%) biogeographic regions. The results indicate that climate change combined with anthropogenic pressures, is expected to reduce brown bear habitat suitability by 40%-48% by 2050, and 40%-67% by 2070 under various scenarios. A significant contraction in the brown bears' range, along with a northward shift in suitable habitats, is projected, reflecting the broader impacts of climate. Additionally, the suitability of brown bear habitats is estimated to be strongly influenced by the changes in altitude. The proportion of suitable habitats under protection is projected to decline from 21.4% to 15%-16.1% by 2050 and further to 11.3%-15.9% by 2070, depending on the scenario. These findings highlight the need for targeted conservation strategies to address the emerging conservation gap for brown bears in the Mediterranean, Irano-Turanian, and Euro-Siberian regions. Enhancing connectivity between fragmented habitats and reassessing the status of protected areas are critical actions to safeguard the brown bear population in Türkiye. This study underscores the pressing conservation challenges and strategic opportunities for securing the future of brown bears in Türkiye.

The effect of ranger patrols on the sighting of large mammals by local herders in Northern Iran

Ranger patrols are essential for biodiversity conservation, particularly in protected areas where they help mitigate poaching of large mammals. Effective patrols reduce poaching and support higher population densities of large mammals. This study investigates the impact of ranger patrols on large mammal sightings in the Central Alborz Protected Area (CAPA), northern Iran, a crucial wildlife corridor with UNESCO-listed Hyrcanian forests and high-altitude grasslands. CAPA also supports livestock grazing in over 200 villages, making it a key area for studying human-wildlife interactions. Data were gathered using semi-structured questionnaires from local herders, whose observations provide valuable insights into wildlife presence and the effectiveness of ranger patrols. The study area was divided into 5 × 5 km grid cells to ensure uniform data collection. Results show that large mammal sightings decrease with increasing distance from active, semi-active, and seasonal ranger stations. This trend is likely due to reduced patrol coverage, which increases poaching risks. Although factors such as habitat preferences and human disturbances may contribute. Inactive ranger stations appear to have lost effectiveness, likely because of the lack of regular patrols, which warrants further investigation. These findings emphasize the critical role of consistent patrol efforts in reducing poaching and maintaining wildlife populations in this ecologically important region.

Climate-driven distribution shifts of Iranian amphibians and identification of refugia and hotspots for effective conservation

This study investigates the potential impacts of climate change on the distribution of Iranian amphibian species and identifies refugia and biodiversity hotspots to inform effective conservation strategies. The study employed ensemble species distribution models to assess the impacts of climate change on 19 Iranian amphibian species. We analyzed future scenarios (2041-2060 & 2081-2100) under a high-emission pathway to identify potential range shifts and refugia (areas with stable or newly suitable climate). Additionally, core habitat overlays were used to map amphibian diversity hotspots and evaluate their coverage within existing protected areas. Climate change is projected to threaten the habitat of most Iranian amphibian species, with potential for some species to expand into new areas. The study differentiates in-situ and potential ex-situ refugia under worst-case climate models (GISS-E2-1-G and MRI-ESM2-0). GISS-E2-1-G suggests expansive refugia encompassing the Hyrcanian forests, Alborz, Zagros, and Kopet Dag mountains, along with the southern coast. MRI-ESM2-0 indicates more restricted refugia in these regions. Importantly, there is an overlap between climatic refugia and existing biodiversity hotspots. However, the overlap between amphibian hotspots and protected areas is currently 7.41%, projected to decrease to 5.30-5.51% by 2081-2100 under both models. This research emphasizes the significance of areas serving as both refugia and biodiversity hotspots for amphibian adaptation and long-term survival. The study proposes a dynamic conservation approach that necessitates continuous assessments and adaptable management strategies to ensure effectiveness in a changing climate.

Predicting the potential habitat of bears under a changing climate in Nepal

In 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 10,971.75 km2 for sloth bears; 29,470.75 km2 for Asiatic black bears; and 6152.97 km2 for brown bears. Within protected areas, the habitat for sloth bears is 4120.56 km2, that for Asiatic black bears is 9688.67 km2, and that for brown bears is 4538.67 km2. Chitwan National Park emerged as the prime sloth bear habitat with a core area of 918.55 km2 and a buffer zone of 726.485 km2. The Annapurna Conservation Area was deemed suitable for Asiatic black bears and brown bears, covering 2802.23 km2 and 2795.91 km2, respectively. The models projected a significant reduction in the habitat of these bear species both inside and outside protected areas. As predicted under the Shared Socioeconomic Pathways (SSP)2-4.5 scenario, sloth bears may experience 54.9% (2050) and 44.7% (2070) losses, respectively, of habitat; Asiatic black bears, 11.2% (2050) and 16.8% (2070); and brown bears, 68.41% (2050) and 82.20% (2070) losses. The overlap between sloth bears and black bears spans 38.7 km2, and that between brown bears and black bears is 26.6 km2. Notably, all three bear species exhibited suitability correlations with the intermediate temperature of the driest quarter. Examining current and projected habitats provides essential information for guiding conservation strategies and ensuring the conservation of these bear species in the face of climate change.

Energy-based corridor identification for mammals between protected areas in Iran

Body mass plays a crucial role in determining the mass-specific energy expenditure during terrestrial locomotion across diverse animal taxa, affecting locomotion patterns. The energy landscape concept offers a framework to explore the relationship between landscape characteristics and energy expenditure, enhancing our understanding of animal movement. Although the energy landscape approach solely considers the topographic obstacles faced by animals, its suitability compared to previous methods for constructing resistance maps and delineating corridors has not been comprehensively examined. In this study, we utilized the enerscape R package to generate resistance maps in kilocalories (kcal) by incorporating digital elevation models (DEMs) and body size data (kg). We assigned body sizes ranging from 0.5 to 100 kg to encompass a wide range of small and large mammals in Iran, adjusting maximum dispersal distances accordingly from 50 to 200 km. By analyzing these scenarios, we produced four resistance maps for each body size. Next, we identified potential corridors between terrestrial protected areas in Iran using the Linkage Mapper toolkit and examined barriers and pinch-points along these paths. Our study revealed significant findings regarding the shared corridors between small and large mammals in Iran's landscape. Despite their differing body sizes and energy requirements, many corridors were found to be utilized by both small and large mammal species. For example, we identified 206 corridors for mammals weighing 500 g, which were also recognized as the least-cost paths for 100 kg mammals. Thus, embracing a comprehensive method in resistance map creation, one that incorporates species-specific traits and human infrastructure becomes imperative for accurately identifying least-cost paths and consequently pinpointing pinch points and barriers.

Demystifying global climate models for use in the life sciences

For each assessment cycle of the Intergovernmental Panel on Climate Change (IPCC), researchers in the life sciences are called upon to provide evidence to policymakers planning for a changing future. This research increasingly relies on highly technical and complex outputs from climate models. The strengths and weaknesses of these data may not be fully appreciated beyond the climate modelling community; therefore, uninformed use of raw or preprocessed climate data could lead to overconfident or spurious conclusions. We provide an accessible introduction to climate model outputs that is intended to empower the life science community to robustly address questions about human and natural systems in a changing world.

Spatio-temporal genetic structure of the striped field mouse (Apodemus agrarius) populations inhabiting national parks in South Korea: Implications for conservation and management of protected areas

Population or habitat connectivity is a key component in maintaining species and community-level regional biodiversity as well as intraspecific genetic diversity. Ongoing human activities cause habitat destruction and fragmentation, which exacerbate the connectivity due to restricted animal movements across local habitats, eventually resulting in the loss of biodiversity. The Baekdudaegan Mountain Range (BMR) on the Korean Peninsula represents “biodiversity hotspots” and eight of the 22 Korean national parks are located within the BMR. Given the striped field mouse (Apodemus agrarius) is the most common and ecologically important small mammals in these protected areas, the population genetic assessment of this species will allow for identifying “genetic diversity hotspots” and also “genetic barriers” that may hinder gene flow, and will therefore inform on effective conservation and management efforts for the national park habitats. We collected samples from hair, tail, or buccal swabs for 252 A. agrarius individuals in 2015 and 2019. By using mitochondrial DNA cytochrome b (cyt b) sequences and nine microsatellite loci, we determined levels of genetic diversity, genetic differentiation, and gene flow among eight national park populations of A. agrarius along the BMR. We found high levels of genetic diversity but the occurrences of inbreeding for all the nine samples analyzed. Our results also indicated that there was detectable temporal genetic variation between the 2015 and 2019 populations in the Jirisan National Park, which is probably due to a short-term decline in genetic diversity caused by reduced population sizes. We also found a well-admixed shared gene pool among the national park populations. However, a significant positive correlation between geographic and genetic distances was detected only in mtDNA but not microsatellites, which might be attributed to different dispersal patterns between sexes. There was a genetic barrier to animal movements around the Woraksan National Park areas. The poor habitat connectivity surrounding these areas can be improved by establishing an ecological corridor. Our findings of the presence of genetic barriers in some protected areas provide insights into the conservation and management efforts to improve the population or habitat connectivity among the national parks.

Influence of land use changes on landscape connectivity for North China leopard (Panthera pardus japonensis)

North China leopard (Panthera pardus japonensis) is the most widespread subspecies of leopard and one of the rare and endangered species in China. It is currently confined to several isolated natural reserves, and little is known about its habitat network connectivity with land use changes. This study was conducted to assess the impacts of land use changes on landscape connectivity for North China leopard in the Great Taihang Region. Circuit theory-based connectivity models and least-cost path analyses were used to delineate pathways suitable for species movement, and evaluate the impacts of land use changes on landscape connectivity. The results revealed that there were 37 least-cost paths in 1990 and 38 in 2020. The area of forest land increased from 57,142.74 km2 to 74,836.64 km2, with the percentage increasing from 26.61% to 34.85%. In general, the increase in forest land area promoted the landscape connectivity for North China leopard at broad spatial scales. The improvement of landscape connectivity was not always consistent with the land use changes, and there was a slightly decreasing trend on connectivity in some key movement barrier areas with high intensity of human activities. Improving landscape connectivity at broad spatial scales is as important as protecting the habitats (natural reserves) where the species lives. Our study can serve as an example of exploring the relationships between land use changes and landscape connectivity for species conservation at broad spatial scales with limited movement pattern data. This information is proved to be critical for enhancing landscape connectivity for the conservation concern of North China leopard and planning of natural reserves network.

Genetic Analysis and Status of Brown Bear Sub-Populations in Three National Parks of Greece Functioning as Strongholds for the Species’ Conservation

In order to optimize the appropriate conservation actions for the brown bear (Ursus arctos L.) population in Greece, we estimated the census (Nc) and effective (Ne) population size as well as the genetic status of brown bear sub-populations in three National Parks (NP): Prespa (MBPNP), Pindos (PINDNP), and Rhodopi (RMNP). The Prespa and Pindos sub-populations are located in western Greece and the Rhodopi population is located in eastern Greece. We extracted DNA from 472 hair samples and amplified through PCR 10 microsatellite loci. In total, 257 of 472 samples (54.5%) were genotyped for 6–10 microsatellite loci. Genetic analysis revealed that the Ne was 35, 118, and 61 individuals in MBPNP, PINDNP, and RMNP, respectively, while high levels of inbreeding were found in Prespa and Rhodopi but not in Pindos. Moreover, analysis of genetic structure showed that the Pindos population is genetically distinct, whereas Prespa and Rhodopi show mutual overlaps. Finally, we found a notable gene flow from Prespa to Rhodopi (10.19%) and from Rhodopi to Prespa (14.96%). Therefore, targeted actions for the conservation of the bears that live in the abovementioned areas must be undertaken, in order to ensure the species’ viability and to preserve the corridors that allow connectivity between the bear sub-populations in Greece.