Seasonal variations in the time–activity budget of Royle’s pika in the Western Himalaya,India

ABSTRACT

The time–activity budget of a species has ecological relevance because natural selection often favours individuals that utilise their time most efficiently. Details of time–activity budgets can provide information on how animals allocate time to their various activities through the day and during different seasons to most efficiently cope with varying energy demands and environmental changes that may threaten their survival. Efficient use of time–activity budget is also crucial for alpine small mammals, which live in a highly seasonal environment with restricted periods in which to gain energy and successfully reproduce. Hence, variations in the time–activity budget of the high-elevation lagomorph Royle’s pika (Ochotona roylei) were analysed during different seasons over 2 years across an elevational gradient (2900–3680 m). Seven behavioural conditions were recorded in adult and juvenile pikas through daily focal sampling between 0600 and 1900 hrs. Royle’s pika had bimodal activity: animals were most active during the morning and early evening and relatively inactive during midday hours. Adult pikas allocated the largest proportion of their time–activity budget to foraging and the smallest proportion to vocalisation. Greater food availability during the monsoon season encouraged pikas to spend more of their time foraging than on other activities. In the autumn, pikas spent more time on locomotory and musing activities. Vigilance activities were most frequent during midday hours, possibly due to a high risk of predation. Locomotion and foraging were the predominant behaviours of juveniles during the summer and monsoon seasons. Prominent food hoarding activities were not observed in either adult or juvenile pikas. Information on time allocation to different activities during different seasons should provide a baseline for future behavioural ecology and bioenergetic analyses of pikas and help to understand their potential for adaptation to climate change.