Pastoralism in the high Himalayas: Understanding changing practices and their implications for parasite transmission between livestock and wildlife

Rangelands are increasingly being affected by climatic variations, fragmentation and changes in livestock management practices. Along with resource competition between livestock and wildlife, disease transmission has implications for people and wildlife in these shared landscapes. We worked with two pastoral communities in the Western Indian Himalayas: the migratory Kinnauras that travel to the Trans-Himalayan Pin valley in summer and the resident herders of Pin Valley. Asiatic ibex (Capra sibirica) is the predominant wild herbivore in Pin. The pastures in Pin are grazed by both livestock (migratory and resident) and ibex, with the potential for disease transmission. We investigate the effects of herding practices on livestock health and disease transmission, while focusing on gastro-intestinal nematodes (GINs) as they can spread by sharing pasture between wild and domestic ungulates. Surveys were carried out between June and August 2019, the period when migratory Kinnauras, local herders and Asiatic Ibex are found in Pin Valley. We found that the Kinnaura flocks share pasture with ibex during their time in Pin, exhibiting significantly higher endo-parasite burdens than sedentary livestock, and the Kinnaura flocks are increasing in number. This suggests GIN cross-transmission is possible, as GINs have low host specificity and a free-living, environmental stage that is trophically acquired. As local (sedentary) sheep and goats rarely share pasture with ibex, have low endo-parasite burdens and are few in number, they are unlikely to transmit parasites to ibex. However, increasingly large local stock numbers may be contributing to pasture degradation which could cause nutritional stress and resource competition, exacerbating GIN impacts. We also find evidence for transhumance persisting, in spite of signs of pasture degradation that are seemingly affecting livestock productivity and potentially disease transmission. It is critical that proactive measures are taken, like participatory disease management with the Kinnauras, to align livelihoods with wildlife and rangeland conservation.