Climate and the landscape of fear in an African savanna.

摘要: Summary Herbivores frequently have to make trade-offs between two basic needs: the need acquire forage and avoid predation. One manifestation of this trade-off is ‘landscape fear’ phenomenon – wherein herbivores areas high perceived predation risk even if abundant or quality in those areas. Although well established among invertebrates, its applicability terrestrial large remains debated, part because experimental evidence scarce. This study was designed (i) experimentally test effects tree density a key landscape feature associated with for African ungulates on herbivore habitat use (ii) establish whether patterns could be explained by foraging opportunities avoidance. In Kenyan savanna system, replicate plots dominated Acacia drepanolobium were cleared, thinned left intact. Ungulate responses measured over four years, which included years moderate rainfall as severe drought. Under average conditions, most (primarily plains zebra, Grant's gazelle hartebeest) favoured sites fewer trees higher visibility regardless grass production while elephants (too vulnerable predation) many trees. During drought, however, that had biomass, but not visibility. Thus, during sought where food more abundant, despite probable predation. These results illustrate fear’, interactions top-down bottom-up effects, static, rather shifts markedly under different conditions. Climate thus has potential alter strength spatial dynamics behaviourally mediated cascades systems.