| | 要旨トップ | 目次 | | 日本生態学会第73回全国大会 (2026年3月、京都) 講演要旨 ESJ73 Abstract |
一般講演(口頭発表) L02-12 (Oral presentation)
Fear of predation can shape ecosystem dynamics more profoundly than direct predation itself, yet the non-consumptive effects of apex predators remain unexplored in most Asian temperate systems. We leveraged a nation-wide camera-trapping dataset (Snapshot Japan 2024; 11 sites with bears in a total 28 sites and 289 cameras) to investigate whether the presence of Asiatic black bears (Ursus thibetanus japonicus) and brown bears (Ursus arctos)—Japan’s last remaining large-bodied predators—creates a “landscape of fear” for three native ungulate species: sika deer (Cervus nippon), Japanese boar (Sus scrofa leucomystax), and Japanese serow (Capricornis crispus). Using a quasi-experimental design comparing sites with and without bear populations, we tested for shifts in ungulate activity and habitat use. Our analyses sought to determine whether these herbivores adjust their behaviour in response to bear predation risk, despite bears being facultative predators whose predation pressure pulses with mast failures. Preliminary results indicate that ungulates may exhibit nuanced behavioural responses to bear presence, though the magnitude and direction of these shifts varied among species and habitats. Where fear effects were detected, it suggests that ungulates balance risk avoidance against resource acquisition in complex ways. These findings contribute the first empirical assessment of fear ecology in Japanese forest ecosystems and offer a novel omnivore-driven perspective to the global predator–prey literature. Critically, understanding whether the absence of predators in Japan has released ungulates from fear-mediated constraints may inform ongoing debates about large carnivore reintroduction and the cascading consequences of predator loss in the Anthropocene.