Reindeer green‐wave surfing constrained by predators

Ecosphere

Inger Maren Rivrud¹  Atle Mysterud¹  Anna Skarin²  Therese Ramberg Sivertsen²  Birgitta Åhman²  Ole‐Gunnar Støen³ 

[1] Centre for Ecological and Evolutionary Synthesis Department of Biosciences University of Oslo P.O. Box 1066, Blindern NO‐0316 Oslo Norway;Department of Animal Nutrition and Management Swedish University of Agricultural Sciences P.O. Box 7024 750 07 Uppsala Sweden;Department of Ecology and Natural Resource Management Norwegian University of Life Sciences P.O. Box 5003 1432 Ås Norway;

关键词: energy landscapes;    forage maturation hypothesis;    landscape of fear;    movement patterns;    predation;    semi‐domestic reindeer;   

DOI  :  10.1002/ecs2.2210

来源: DOAJ

【 摘 要 】

Abstract Migratory large herbivores in seasonal environments are known to follow the onset of new growth during spring, so‐called green‐wave surfing. This ensures prolonged access to forage with an optimal balance between forage quality and quantity. Many studies have focused on herbivores’ ability to follow the spring flush, but without considering potential constraints to surfing the green wave. The presence of predators is likely to be such a limitation, which could force herbivores to deviate from the optimal movement patterns in terms of forage access. We compared how well 319 reindeer (Rangifer tarandus) from seven different populations followed the green‐up at different population densities of brown bear (Ursus arctos). We found that reindeer at higher bear densities selected movement paths with lower access to high‐quality forage and deviated more in time from following the peak of the green wave, thus missing out on valuable forage. In addition, reindeer generally moved faster at higher bear densities, but this pattern was more consistent in forest habitats. Our results indicate that reindeer are forced to deviate from following the spring flush and alter their movement pattern in areas with high bear densities, which may lead to reduced body condition for reindeer experiencing high predation risk. With the recent recolonization of large carnivores in northern ecosystems, it is critical to understand the direct and indirect effects of predators on large herbivores in order to assess effects on population dynamics and potentially cascading consequences on ecosystem function.

【 授权许可】

Unknown