Harmony at Heights? Spatio-temporal interactions between meso-carnivores in the High Himalayas

Species interactions are complex and dynamic. A nuanced understanding of species interactions can help understand factors shaping species assemblages and communities while also providing baseline ecological information for conservation. Our study contributes to this emerging knowledge by focusing on spatio-temporal interactions among mesocarnivores under varying ecological stress. High mountain ecosystems are often characterised by low productivity, where resource limitations play crucial role in shaping community dynamics. In such environments, the stress gradient hypothesis predicts that species interactions become more facilitative (or neutral) under increasing environmental stress. This framework provides a useful lens to examine how mesocarnivore interactions may shift under varying stress levels. We analysed the patterns of interaction between Vulpes vulpes (red fox) and Martes foina (stone marten), under varying stress levels across 14 sites covering c.31,000 sq.km. We predicted red fox and stone marten to have more negative interactions leading to low spatio-temporal overlap in sites with lower stress (High NDVI and low snow leopard density). The species interaction factor (SIF) ranged from 0.9 to 1.29 across the 14 sites indicating neutral to positive or non-significant negative spatial association. Activity pattern also highly overlapped regardless of stress levels. Our findings don’t provide support for the stress gradient hypothesis. Given the low variation in stress across sites, our result suggest that the stress gradient hypothesis is only relevant when the stress gradient is stark enough. The largely neutral patterns observed highlight the need for further research into ecological and behavioural processes that may underlie mesocarnivore co-occurrence in resource-stressed landscape.

Keywords: Red fox, stone marten, co-occurrence, stress gradient hypothesis, camera trap

A Dissertation prepared for partial fulfilment of the requirement for the Master of Science (M.Sc.) degree in Wildlife Science of University of Kota. Submitted to: Department of Wildlife Science, University of Kota, Kota, Rajasthan, India. 106 pp.