The influence of natural and anthropogenic factors in Rangifer movements and habitat use

Rangifer tarandus (reindeer and caribou) is a circumpolar species inhabiting the Arctic and sub-arctic regions of Eurasia and North America. It is a key species in the northern hemisphere and has for centuries been a vital resource for many communities and indigenous peoples in the Arctic. In Fennoscandia most reindeer are semi-domesticated, while smaller herds of wild reindeer exist in mountainous areas in southern Norway and forested areas in eastern Finland. Reindeer herding forms a basis for the Sámi cultural heritage and is an essential economic income to many people within the Sámi society in Fennoscandia. In accordance with international agreements, there is a management goal in Norway and Sweden to ensure the livelihood of the Sámi people, including a sustainable reindeer husbandry, alongside with conservation of landscapes and biodiversity (Nilsson-Dahlström 2003). Although reindeer are domesticated they are freely ranged within the borders of the herding districts, and their behaviour and habitat selection are comparable to wild reindeer and caribou. Rangifer have developed in areas with high spatial and temporal heterogeneity in resource availability. Throughout the year the animals follow the seasonal changes in forage quantity and quality, and depend on access to large heterogeneous land areas to meet their energetic demands (Klein 1970). A constantly increasing infrastructure development has largely changed the terms for the reindeer and the reindeer husbandry in Fennoscandia. Further challenges are caused by the recent 20-30 years of growing predator populations, with a consequent need for management to find compromises between the conflicting interests of carnivore conservation and a sustainable reindeer husbandry. The main predators of semi-domesticated reindeer in Fennoscandia are the large carnivores: lynx (Lynx lynx), wolverine (Gulo gulo), brown bear (Ursus arctos), wolves (Canis lupus) and golden eagle (Aquila chrysaetos). Direct losses of reindeer to predation can be substantial (Danell 2011, Hobbs et al. 2012). However, the total effect of predation on herd productivity is still subject to debate. Also, we lack knowledge about behavioural interactions with predators and antipredator strategies in semi-domesticated reindeer. Anthropogenic activity and infrastructure development is threatening Rangifer in large parts of its range. Human development can cause habitat loss by direct cover of areas, 7 indirectly from avoidance effects or by making movements barriers. This can lead to important transport corridors being cut off, and loss of feeding grounds and critical habitats such as calving areas. Changes in foraging conditions do not only have immediate effects on the animal but also affect future performance and its progeny during several years ( Gaillard et al. 2000). The aim of the present review is to give an overview of the existing knowledge of Rangifer foraging and antipredator behaviour, and impact of human disturbance on Rangifer habitat use. As a theoretical framework I briefly summarize the main theories of foraging and antipredator behaviour in ecology. Finally I discuss the current and future challenges and knowledge gaps related to management of reindeer herding areas in Fennoscandia