Discussion

​The conservation status of the red panda is a barometer of regional conservation efforts for monitoring the integrity of the Eastern Himalayan Broadleaf and Conifer Eco-region (Williams 2003). This study represents a major advance on past sparse and the restricted study which has principally relied on historical anecdotal information. Using extensive field-based survey ever conducted in Western Nepal, spanning red pandas’ range districts of Western Nepal, we demonstrate how bioclimatic variables can be used to identify potential suitable habitat along with primary habitat requirements, distribution and potential corridor for the red panda conservation.
Based on extensive field survey and predictive potential habitat suitability model using bioclimatic variables to build a Maxent habitat model of red panda in Western Nepal. Our major findings have been 1) Potentially suitable habitat in Western Nepal, 2) Important attributes that influence red panda presence and 3) Number of potential corridors in Western Nepal. Our result with regards to total potential red panda habitat, habitat preference and potential corridors in Western Nepal could be critical for setting appropriate management goals, monitoring effectiveness, informing policymakers, and other relevant stakeholders. Western Nepal harbors 3,222 km2 i.e. 23.38 % according to Panthi et al. (2019) and 14.86 % as per Thapa et al. (2020) of potential red panda habitat in Nepal. This might suggest that Western Nepal has suitable ecological variables such as bamboo cover, canopy cover, aspects and water body needed for red panda survival.
Our study concluded that tree and bamboo cover, proximity to the water body and aspect were the strongest predictor of red panda distribution which is supported by findings of previous studies (Thapa et al. 2020; Thapa et al. 2018; Bista et al. 2017; Dorji et al. 2011; Williams 2006; Pradhan et al. 2001; Yonzon & Hunter 1991a). Tree canopy cover has structured an ideal microclimatic setting (e.g., temperature, relative humidity; Anhuf & Rollenbeck 2001) which favored the better growth of the understory of bamboo (Thapa et al. 2018) and also provide shelter and protection (Thapa et al. 2020; Bista et al. 2019; Pradhan et al. 2001; Yonzon & Hunter 1991a). Also, canopy cover contributes for the safety shelter away from the avian predators which could showed the high record of fecal pellets in the tree branches. Also, 62.21 % of the red panda latrine site was recorded on tree branches. This might be due to as tree provides better shelter and safety from predators and easy movement from the branches of trees (Reid et al. 1991; Pradhan et al 2001; Thapa et al. 2020).
The presence of bamboos was observed in 85% of sign plots. This demonstrates the importance of bamboos as one of the fundamental parameters affecting red panda distribution (Yonzon & Hunter 1991b; Fox et al. 1996; Williams 2004; Dorji et al. 2011). Bamboo species contributes more than 90% food of the Himalayan red panda (Thapa et al. 2020; Panthi et al. 2019; Sharma et al. 2014 Pradhan et al. 2001; Yonzon & Hunter 1989). Besides bamboo species, other food such as seasonal fruiting berries contribute a very little proportion in food of the red pandas (Yonzon & Hunter 1991b). Such a near inclusive reliance on bamboo may be a survival strategy. Proximity to bamboo lessens the travel needed to forage, which conserve red panda energy (Hu 2001; Reid et al. 1991).
Occurrence of Himalayan red panda is positively associated with distance to water resources. Almost 90 of red panda fecal pellets were recorded within 150 m which might suggested that red panda frequently need water for their physiological food processing due to poor digestive system. Our findings are identical to the results of previous studies (Yonzon & Hunter 1991b; Pradhan et al. 2001; Williams 2006; Dorji et al. 2011; Bista et al. 2017; Thapa et al. 2018). Such proximity might help the red panda to avoid predators such as snow leopard, marten, and human and conserve its energy (Pradhan et al. 2001; Bista et al. 2017). Proximity to the water is important to conserve their energy as they do not require a long distance to travel for water (Bista et al. 2017; Pradhan et al. 2001). Also, this might be also due to low water content associated with bamboo leaves (Reid et al. 1991; Wei et al. 1999b). In Wolong Reserve, the water content in their scat was 72.4±5.5%, and that in B. faberi leaves 59.7±8.1 % or less than 12.7 % less than in the scat. (Johnson et al.1988). In the wild, their traces, including fecal pellets, foraging sites were frequently found at a site close to the water body. For instance, in Mabian Reserve, red pandas often foraged at sites less than 200 m away from the water body (Wei et al. 1999a). In CHAL, observation indicated that proximity to water may be an important habitat requirement because 90 % of the fecal pellets were found within 100 m of the nearest water body (Bista et al. 2017).
Red pandas were detected more frequently on northerly and westerly slopes in our study, which supports similar observations by Yonzon (et al. 1991a) in Langtang National Park. Yonzon (et al. 1991a) hypothesized that the Northern slope receives fewer sunlight periods which are conducive to the growth of fir-jhapra bamboo forest. In Jigme Dorji and Thrumshingla National Parks, Bhutan, red pandas were associated strongly associated with southerly slopes as southerly slope receives direct sunlight during winter and red pandas rested in direct sunlight during winter to reduce heat loss (Reid et al. 1991).We noted that northerly and westerly slopes in our study areas had relatively high bamboo densities, which might be associated with sunlight and rainfall. Due to the lack of detailed knowledge of bamboo ecology in Nepal, more studies are needed to investigate the effects of the physical landscape variables on bamboo species.
In Nepal, forests are integral to human subsistence, however, because of the common reliance on forests by humans and red pandas, sustainable management of natural resources is critical to meet the needs of both people and red panda conservation. This proposes that red pandas are primarily dependent on bamboo species. Bamboo species are vulnerable to climate change because of their uncommon reproduction intervals (Janzen 1976), apart from limited seed dispersal capacity (Taylor et al. 1991; Mao Ning et al. 2012). To ensure red panda survival bamboo conservation should be the highest importance. Therefore, the establishment of red panda focused conservation zones is needed to secure the long-term survival of red pandas through maintaining habitat connectivity that ensures the conservation of a genetically viable population in the long run. This study recommended potential five potential corridors in western Nepal. Although, a detailed field-based assessment is needed to validate it scientifically.

The present study identified five potential corridors in Western Nepal with an important cluster in Jumla, Jajarkot, and Dolpa district. These corridors are the vital repository of biodiversity in this region. Although, biodiversity of the suggested corridor has not been affected by any detrimental development activities, the same cannot be forecast for the future. It is imperative that the partnerships and collaborations with the community should be nurtured to ensure the long-term conservation of suggested the corridor. This study also further highlighted the need for site-specific conservation strategies that need to be bolstered with comprehensive information on bamboo distribution, other palatable species, and microclimatic conditions.