Attacked from two fronts: Interactive effects of anthropogenic and biotic disturbances generate complex movement patterns

Abstract

Anthropogenic and biotic disturbances have the potential to interact, generating cumulative impacts on animal movement or, alternatively, counterbalancing or masking each other. Despite their importance, those interactions have not been investigated thoroughly. Our study aimed to fill this knowledge gap by assessing the combined effects of a human activity-that is, military exercises-and a biotic disturbance-that is, insect harassment-on movement rates of free-ranging semidomesticated reindeer (Rangifer tarandus tarandus). From 2010 to 2012, we analyzed location data from fifty-one Global Positioning System (GPS)-collared female reindeer in the largest European military test range, situated in northern Sweden. In the presence of both military exercises and mosquito harassment, reindeer reacted by increasing their movement rates but not as much as when mosquito harassment occurred alone. Conversely, reindeer reduced their movement rates during military exercises performed with aircraft. Moreover, the effect of military exercises performed with vehicles was evident only when combined with mosquito harassment. These results stress the value of evaluating the effects of the interaction between biotic disturbances and human activities, especially in northern ecosystems, because of the predicted climate warming and the growing interest toward natural resource extraction and other forms of land use.

Occurrence of Conspecific in the Neighboring Space Influence on Flight Initiation Distance in Cape Hare <i>Lepus capensis</i> under Human Stimuli

“…Hunted animals tend to exhibit greater FIDs than non-hunted ones (e.g., Masai giraffes Giraffa camelopardalis tippelskirchi [4] [6] [7] [8]); reindeer; Rangifer tarandus [9]), and temporal variations in human presence elicit changes in FID [10]. Nonetheless, habituation of wild animals to human presence is widespread [11] [12]. Directly attributing variation in escape behavior to fitness is problematic [13]; however previous studies on different taxa have recognized survival effects in animals escaping from humans.…”

Reindeer husbandry in peril?—How extractive industries exert multiple pressures on an Arctic pastoral ecosystem

“…Besides human activity and noise, main issues include erosion, contamination and compaction of snow and soil due to heavy bandwagons and missile testing (Lawrence et al, 2015). The effects of military and recreational activities on mobile wildlife and pastoralists are often difficult to quantify due their high spatiotemporal unpredictability and dependence on environmental conditions, such as snow cover (Valente et al, 2020).…”

Estimation of trends in zone of influence of mine sites on barren-ground caribou populations in the Northwest Territories, Canada, using new methods

“…Monitoring the zone of influence (ZOI) helps verify environmental assessment impact predictions, test the effectiveness of mitigation measures, and is the basis of an approach to quantify the energetic cost of caribou avoidance of mine vicinity. Estimates of ZOI for migratory tundra caribou differ among studies (Plante et al 2018) which is, however, not surprising given all the factors which affect caribou habitat selection such as type of development and insect harassment (Valente et al 2020).…”