Responses of red deer (Cervus elaphus) to regular disturbance by hill walkers

Disturbance to wildlife from human recreational activities is increasing as remote areas become accessible to greater numbers of people. We used Global Positioning System tracking collars to monitor the movements of red deer ( Cervus elaphus ) stags ( n = 8) in a herd whose feeding grounds lie close to a popular walking track in the Highlands of Scotland. The track is used by around 20,000 walkers per year and is busiest in summer and at weekends. In a 2-year study, the locations of collared deer were recorded at 2-h intervals on typically busy days (Sundays: mean number of walkers = 204) and quiet days (Wednesdays: mean number of walkers = 49) during May and June. The deer were consistently further from the track on Sundays than Wednesdays (371 vs 286 m) and moved greater distances between fixes (365 vs 308 m). The amount of time spent (percentage of total fixes) in the small area of grassland closest to the track was lower on Sundays than Wednesdays (6% vs 13%). Although 97% of walkers use the track during the day (between 0800 and 2000 h), there was no evidence of compensatory use of grassland at night, when the deer moved to higher ground dominated by heather moorland. The results demonstrate that animals which appear to be habituated to regular disturbance within their home territory may nevertheless alter their behaviour and potentially diet composition, as a result of that disturbance.