Protected areas (PAs) are crucial for conservation but individual PAs may be too small to support stable populations of large wide-ranging mammals (Mohammadi et al., 2021; Rezaei et al., 2022; Dutta et al., 2005). The rapid conversion of natural habitats outside protected areas is leading to habitat fragmentation and isolation of PAs (DeFries et al., 2005). Connectivity corridors are crucial for the long-term viability of a species as they facilitate the species movements from one habitat to another to maintain gene flow. Some animals exhibit a one-time movement such as ‘dispersal from natal habitat’ (e.g., tiger). Also, some animals exhibit regular (seasonal) movements (to and like migration (e.g., elephant, several species of birds, etc.) (Nayeri et al., 2022). Fragmented and altered habitats have modified and decreased connectivity for species, thereby restricting the species’ movement. Globally, many connectivity studies have focused on a single species or groups of closely related taxa (Haddad et al., 2003; Ersoy et al., 2019; Brennan et al., 2020; Lookingbill et al., 2022).In Iran and Iraq studies have been focused on Brown bear and Persian leopard habitat connectivity (Ashrafzadeh et al., 2020; Kaszta et al., 2021). Corridors have been identified for ‘flagship species’ such as the Giant panda (Ailuropoda melanoleuca) (Wang et al., 2014; Hou et al., 2014), Red panda (Ailurus fulgens) (Tobgay and Mahavik, 2020), and Bengal tiger (Panthera tigris) (Yumnam et al., 2014; Mondal et al., 2016). Various approaches are being advanced to model connectivity for different species, each offering unique insights into how animals move across landscapes. One common method involves habitat suitability models, which identify areas most favorable for a species based on environmental factors such as food availability, cover, and terrain. These models are often paired with least-cost path analysis, a technique that predicts the most efficient movement corridors by estimating the easiest or least ‘costly’ routes for animals to traverse between key habitats, avoiding barriers like roads or developed areas. On the other hand, landscape connectivity models such as Circuitscape take a more comprehensive approach by simulating multiple potential movement paths. Unlike least-cost path analysis, Circuitscape ensures redundancy in corridor identification by accounting for various pathways an animal might use, including those that may not be the most direct but are still critical for long-term connectivity. This multi-path simulation is particularly important for maintaining ecological resilience, as it helps safeguard against the disruption of a single corridor due to environmental changes or human activities. Genetic studies assess gene flow between fragmented populations, revealing how habitat connectivity affects genetic diversity. The creation of wildlife corridors, including natural habitat linkages and artificial structures like overpasses and underpasses, allows safe passage across human-altered landscapes, particularly around roads. Remote sensing and satellite imagery further enhance the understanding of land-use changes and their impact on corridor connectivity, while community-based conflict mitigation strategies in agricultural and livestock-dominated areas help minimize human-wildlife conflicts (Koen et al., 2014; Brodie et al., 2015; Choe et al., 2017). In Sikkim, over 47.08% of the total geographical area is forested (India State of Forest Report, 2021), yet there is limited information on the connectivity between habitat patches outside protected areas, where anthropogenic activities have a substantial effect. This is particularly concerning given that four of the eight bear species found globally are native to the Indian subcontinent. Among these, the Asiatic black bear (Ursus thibetanus) has been prioritized for conflict mitigation efforts due to its frequent interactions with humans (Can et al., 2014). Understanding the connectivity between habitats, especially outside protected areas, is essential for effective conservation and conflict reduction for this species. The species is listed globally as Vulnerable in the IUCN (A2CD) Redlist, Appendix I in CITES, and Schedule II of Indian Wildlife (Protection) Act, 1972. A significant level of variation in distribution ( Figure 1 ) exists for Asiatic black bears, much of which is attributed to differences in habitat types, climate, food availability, topography, and other geographical differences (Sathyakumar and Choudhary, 2007; Bashir et al., 2018). Most of the suitable habitats for U. thibetanus are in forested mountain habitats in the Indian Himalayan region and hills of northeast of India up to treeline (4300 m in eastern Himalaya) characterized by inaccessible terrains, thick understory vegetation, abundant food resources, and good denning sites (Sathyakumar, 2001; Sathyakumar and Choudhary, 2007; Sathyakumar et al., 2012; Bista and Aryal, 2013). The unavailability of food resources often compels Black bears to move into anthropogenic areas, leading to increased human-wildlife conflicts (Sharma et al., 2010; Bashir et al., 2018). Asiatic black bear requires expansive areas to sustain viable populations, with home range estimates of 107.23 km² for males and 49.53 km² for females in the Kashmir Himalaya, India (Sharma et al., 2010). Telemetry studies, such as those conducted in China (Reid et al., 1991), Japan (Ohsako, 1995), and India (Ashraf, 2008), have been instrumental in providing detailed insights into the home range, habitat use, and movement patterns of black bears (Charoo et al., 2011). These studies help in understanding how black bears utilize large landscapes, which is crucial for their conservation, as they highlight the spatial requirements necessary for population viability and inform strategies for habitat protection and connectivity (Marifatul Haq et al., 2022).

Black bears in Himalaya rely on Climatic information to use the habitat connectivity as they inhabit a wide range of elevations, from subtropical forests to alpine regions, where temperature, precipitation, and seasonal variability greatly influence habitat availability and food resources. Climatic factors such as temperature and moisture levels directly affect vegetation types and abundance, which are critical for the bear’s diet and shelter. Black bears exhibit seasonal migrations in response to climate-driven changes in food availability. For instance, in higher elevations, bears often move to lower altitudes during winter months to escape harsh climatic conditions. These seasonal shifts highlight the importance of climate in determining the timing and routes of their movements, and thus habitat connectivity. Thus, climate plays a significant role in determining the bear’s movement patterns and habitat use.

With this background information, the objectives of this study were: 1) to delineate connectivity corridors for Asiatic black bears in Sikkim, identifying areas that ensure long-term connectivity between protected areas, and 2) to identify pinch points where human-black bear interactions are more frequent. The research aimed to address two key questions: (1) What are the critical habitat corridors that facilitate connectivity between protected areas for Asiatic black bears in Sikkim? and (2) Which areas in Sikkim experience the highest frequency of human-black bear conflicts? The underlying hypothesis is that Asiatic black bears use specific natural corridors, such as riparian zones or forest patches, to move between protected areas, and that these corridors are disrupted by human activities like deforestation and infrastructure development.

Species survival depends on their ability to move, adapt to changing conditions, and fulfill seasonal needs, which often extend beyond protected areas (PAs). According to some recent studies habitat loss and fragmentation has accelerated the global extinction crisis (Marifatul Haq et al., 2022), and conservation resources remain limited, therefore it is crucial to identify and prioritize the most critical areas for conservation efforts (Kaszta et al., 2020). Black bears, for example, move across different elevational gradients in search of resources (Izumiyama and Shiraishi, 2004; Sathyakumar and Choudhary, 2007). The Asiatic black bear can navigate human-modified landscapes, such as orchards and tea gardens, for feeding and moving between areas. These areas can serve as corridors, used both day and night, underscoring the importance of PAs and nearby habitats like Reserved Forests (Sathyakumar and Choudhary, 2007). Thus, a well-connected network of PAs is crucial for species survival. Recent research at global level supports the role of corridors in maintaining species viability (Ashrafzadeh et al., 2020; Mohammadi and Almasieh, 2022). Connectivity corridors are vital for preserving gene flow through interpopulation dispersal between isolated habitat patches (Hanski and Ovaskainen, 2000), which positively affects demographic factors and metapopulation dynamics (Hanski, 1998).

Three delineated corridors (i.e., 1. Kyongnosla WLS- Pangolakha WLS; 2. Khangchendzonga NP and Kyongnosla WLS; 3. Maenam WLS and Khangchendzonga NP) fall within reserve forests and have legal protection. The remaining corridors and pinch points ( Figures 4 , 5 ) are outside PAs and reserve forests mentioned below.

Fambhonglho WLS and Khangchendzonga NP ( Figures 4 , 5A ): Our model identified Pinchpoint near two significant human habitats, Mangan and Dikchu. Ground surveys in the two areas confirmed indirect black bear sightings and incidents of human-black bear interface. The number of bear attacks is also high in Singtam, Kazor, and Singhik.

Fambong Lho WLS – Kyongnosla Alpine WLS ( Figures 4 , 5B ): This corridor is close to the state capital, Gangtok. Expansion of urban areas, tourist pressure, and road networks potentially threaten this corridor. The pinchpoint in this corridor is near Pangthang and Kabi. Locals of the area confirmed black bear interface incidents, mainly near agricultural lands. Another Pinchpoint is modelled near Golitar (Near Gangtok). Through ground survey and camera traps, we found direct and indirect evidence of black bear and conflict incidents (with humans and livestock) in the Golitar area.

Khangchendzonga NP and Barsey Rhododendron WLS ( Figures 4 , 5C ): This corridor is in West Sikkim and is close to Yuksum and Pelling. The model corridor pinch point is near Yuksum. We found major human-animal interface incidents reported near the southern buffer range of Khangchendzonga NP. The corridors and pinch points are adjacent to Gerethang reserve forests in west Sikkim. High human-bear interface incidences are reported near Meli, Geyzing, and Singyan. Tourism pressure is a significant threat to this corridor, particularly in areas near Geyzing and Pelling.

Khangchendzonga NP and Shingba WLS ( Figure 4A ): This corridor lies in the North Sikkim near Chungthang and Lachung, connecting Singhba with Eastern parts of Khangchendzonga NP. Locals of Lachung and Chungthang reported interface incidents that happened mainly near maize fields. Maximum number of bear attacks were reported in Lachung, Khedum, Beechu, Bop, Bheemnala, and Lingtem.

Urban expansion poses a significant challenge to conserving corridors, as road networks increasingly fragment the modeled corridors outside protected areas (PAs) and reserved forests (RFs) due to ongoing development activities. Millet and barley fields often serve as black bear interface zones, where local villagers are vulnerable to attacks while protecting their crops and livestock (Abbas et al., 2015; Srivastava and Tyagi, 2016; Jamtsho and Wangchuk, 2016).

The black bears in this landscape frequently encounters humans outside protected areas (PAs) (Bashir et al., 2018). Although 46.93% of Sikkim’s land falls within PAs, human-black bear interactions have increased over the past 10-15 years (Basnett et al., 2020). This rise in conflicts can be attributed to several factors: 1. Failure in mast production within PAs and reserved forests, likely due to climate change. For example, 2009, a drought year with the lowest rainfall in over 40 years, also saw a surge in human-bear conflicts (Rahman et al., 2012). Most conflict zones are in agricultural areas and settlements. There have also been reports of human-bear encounters near major cities in Sikkim (Jamwal, 2018), likely due to large garbage dumps near human settlements (Ghosh, 2018); 2. Increasing urbanization and tourism; and 3. Shortened hibernation periods for black bears at higher elevations, influenced by climate change (Sharma et al., 2010).

The modelled corridors, especially the corridors and pinch points beyond PAs and reserve forests, need to be extensively surveyed to develop a strategic conservation plan to ensure the species’ dispersal and survivability and minimize the human-black bear conflict. Furthermore, a study on the movement ecology of black bears using satellite telemetry is required to understand the functionality of these modelled corridors, identify the spatial and habitat requirements, and detect the hibernation pattern of the species.

The survival of Asiatic black bear is linked to their ability to move across landscapes that extend beyond protected areas (PAs), highlighting the importance of connectivity corridors for facilitating movement, resource access, and gene flow. Habitat loss and fragmentation, driven by urbanization, agriculture, and tourism, threaten these corridors and increase human-wildlife conflicts, particularly between black bears and local communities. Our study identifies critical corridors and pinch points, many of which are outside PAs and reserved forests, emphasizing the need for strategic conservation planning in these areas. Ground surveys and local reports confirm the high frequency of human-black bear conflicts, underlining the urgency of incorporating community-based conservation efforts. Protection of corridors for a large mammal will aid in dispersing other flora and fauna. There are multiple incidents of Human-bear conflict (i.e., crop damage, livestock damage, casualty) outside PAs, especially in the bottleneck corridors identified in this study. We recommend extensive surveys (i.e., camera trapping, sign surveys, scat analysis (for population estimation as well as diet study), interaction with local people for prevention and management of the conflicts) in these bottleneck areas to create habitat management plans to ensure safe dispersal of the species among different PAs. Black bear food plants could be planted in a planned way outside the PA boundaries and along the corridors to reduce human-bear interface to ensure possible movement of black bears inside and outside the PAs. Use of traditional and modern crop protection measures, and sensitization workshops for the locals to be accorded high priority. Informing the potential conflict locations, ways to improve habitats outside PA and available solutions that are essential strategies in the overall restoration effort. Further studies can be carried out to check the transboundary connectivity through satellite telemetry and corridor modelling. As Sikkim shares international boundaries with Bhutan, China, and Nepal, transboundary landscape connectivity will enable genetic dispersal across geopolitical boundaries and maintain Asiatic black bears’ continuous movement in the event of habitat shift or expansion owing to future climate change. The integration of ecological corridors into conservation planning, coupled with efforts to mitigate human-wildlife conflicts, will be crucial for ensuring the long-term survival of black bears in the region.