Temporal shift in activity patterns of Himalayan marmots in relation to pastoralism

Activity patterns of wildlife are often associated with the risk of predation, foraging requirements, and impacts of anthropogenic disturbance. Animals may adjust their temporal niche by shifting their activity patterns in relation to anthropogenic disturbance activities; however, few studies have recorded this response. We investigated the extent to which disturbances associated with pastoralism changed the timing of foraging and activity patterns of Himalayan marmot, a widely distributed rodent that inhabits alpine meadows in the mountains of central Asia. Using a scan-sampling observational approach, we collected data from 30 marmot sites in the Upper Mustang region of Annapurna Conservation Area, Nepal. We developed an index of pastoralism intensity for each site, based on the presence of livestock, herders, guard dogs, distance from pastoralist camps, and density of major tracks. Using this index, marmot time spent above-ground, and foraging distance from burrows, was compared between high and low pastoralism sites. Using a linear mixed modeling approach, there was no significant difference between areas of high and low pastoralism in either the total daily activity time or foraging distance from burrows. However, marmots adjusted their diurnal patterns of activity and the distances moved from their burrows in relation to the timing of pastoralist activities (temporal niche shift). In areas experiencing high levels of pastoralism, marmots were less active during periods of herding activity, and compensated by increasing activity when herding activity was less. By changing foraging behaviors, any increase in pastoralism may have significant consequences in terms of marmot population viability.