Satellite monitoring has revealed the five-day week of the red deer of Glen Lui and the extent of their weekend struggle with hikers.
Four stags from a herd that roams the Scottish highland estate of Mar Lodge were tagged with global positioning system tracking collars in a two-year experiment.
Preliminary results from the study by Angela Sibbald and colleagues at the Macaulay Land Use Research Institute near Aberdeen provide quantitative evidence that hillwalkers -whose numbers are rising -affect the behaviour of deer.
Sibbald's team analysed hourly fixes on the animals' location between 7am and 9pm on Sundays and Wednesdays in May and June of both years.
These data were then compared with the number of hikers attracted to the National Trust for Scotland-owned estate, estimated daily from the read-outs of automatic pathside people counters.
On weekends, when visitor numbers might reach 500 in summer, the deer were more likely to be found in the shelter of woodland, several hundred metres from the track.
During the week, when far fewer people were on the estate, the herd spent more time on better grassland.
"We can infer human disturbance may well be affecting what and how much the deer eat, though I don't think it's at a level that is going to be a particular problem to them," Sibbald said.
To see how far the deer travel in a day, the scientists recorded their positions at 15-minute intervals on one Sunday and one Wednesday a month in May, July, October and November.
Down by the track there was no indication that the deer moved around any more at weekends than during the week. However, when they were up in the hills, they covered twice as much ground on a Sunday than on a Wednesday. It suggests the deer react far more to human presence when they are away from the track and are not expecting it.