Seasonal patterns of resource selection by introduced sika deer (Cervus nippon) in Kaweka Forest Park Recreational Hunting Area, New Zealand

Sika deer (Cervus nippon) have attained high densities within their introduced range in the central North Island, New Zealand. They are an important big-game species for recreational hunters in New Zealand, but they can have unwanted impacts on native plants, such as reducing seedling growth rates. Management of sika deer requires detailed knowledge about which resources are important to them and how resource selection changes temporally. Using GPS location data, we assessed temporal (diel and seasonal) resource selection by male (n = 10) and female (n = 16) sika deer in Kaweka Forest Park Recreational Hunting Area, over a 15-month period. We found that sika deer were associated with ecotones comprising dense forest and open habitats, though the strength of selection for these habitats varied between sexes, time of day and season. Use of open habitats such as alpine and tussock by male and female deer showed complex temporal patterns that were presumably influenced by seasonal food availability and the risk of being seen and shot. Beech forest was an important habitat for sika deer, particularly in winter. Males and females showed strong selection for hollows (slips and guts on hillsides and small creeks with clearings) in most seasons, perhaps because palatable plant species are often associated with those areas. Males showed strong selection for forested terraces during the rut, possibly because these features provided defendable territories and a high number of mating opportunities. Our results indicate where and when aboveground and belowground impacts of sika deer may be highest, which can be used to guide impact monitoring protocols. Additionally, they indicate when sika deer most often use open habitats, where they are most easily observed; potentially increasing ground and helicopter hunting success.