Impacts of human disturbance on flight response and habitat use of red deer

Abstract

Many wild animals perceive humans as predators, and human disturbance,especially in the form of hunting, triggers antipredatory behavior among prey.Yet, knowledge of how game species react to different types of human distur-bance and adapt to repeated disturbances is limited. We investigated howdisturbance in the form of a solitary human approacher (stalker) impactedbehavior (flight response and short-term habitat use) of 28 GPS-collared reddeer (Cervus elaphus) in two populations with contrasting population densitiesin Norway. We studied how the behavioral response differed: (1) with season(pre-hunting vs. hunting); (2) by consecutive approaches within a day;(3) among replicated experiments within the same season; and (4) betweentwo regions with contrasting densities of red deer. The average flight initiationdistance (FID) increased by 15% during the hunting season, and consecutiveapproaches within the same day caused the red deer to move 49% longerdistances. Flight initiation distance was longer in the high-density population,while escape distance was longer in the low-density population. Red deermoved out of their weekly home range after 52% approaches, and after theonset of hunting season, time spent outside the home range increased by 89%.Red deer preferred denser resting sites after the disturbance and animal siteshad shorter sighting distance and higher canopy cover than control plots.Tree density and canopy cover at animal sites increased at the onset of huntingseason, from first to second approach within day, and after replicated experi-ments within season. Our results suggest that red deer preferred dense restingsites, especially in the hunting season. However, these animal sites had thesame amount of the favorable forage plant bilberry (Vaccinium myrtillus), indi-cating no clear food–cover trade-off in selection of habitat. Our study showedthat onset of hunting initiates stronger fear responses in red deer, which mayin turn affect red deer distribution and harvesting efficiency