Abstract 129 – Asiatic black bear responses to roads: Sex- and season-related variations in road proximity, movement, and crossing

Seungyun Baek, Andreas Zedrosser, Tomoko Naganuma, Koji Yamazaki, Shinsuke
Koike

Animals commonly avoid roads and areas close to roads due to the high risk of vehicle collisions
and encountering humans. However, animals can cross roads and/or use roads as well as areas
close to roads to access resources or facilitate movement efficiency. In particular, apex
consumers living in human-modified landscapes must be able to deal with roads due to their
large home range requirements. Understanding how apex consumers respond to roads is
crucial for sustainable human-wildlife coexistence. In this study, we used an integrated step
selection analysis to investigate the selectivity and movement patterns of Asiatic black bears
(Ursus thibetanus) in the Ashio-Nikko Mountains, Japan, in relation to roads (main and minor
roads) and crossing of main roads. During the mating season, adult males preferred areas near
all types of roads but preferred areas further from roads during the day compared to the night.
Adult males also displayed slower movements as well as avoided less dense vegetation near
main roads and showed faster movement near minor roads. Furthermore, adult males
generally avoided crossing of main roads, but this avoidance was lower during the night
compared to the day. In contrast, adult females avoided areas near main roads and preferred
areas near minor roads. In addition, adult females preferred areas further from minor roads
during the day compared to the night. We never observed crossing the main roads by adult
females in the mating season. During the hyperphagia season, neither sex exhibited any
selectivity in relation to roads, but preferred areas further from all types of roads during the
day compared to the night. Moreover, both sexes generally avoided crossing of main roads, but
this avoidance was less pronounced during the night. Our results suggest that Asiatic black
bears generally perceive roads as a risk and that the probability of road crossing and use areas
near roads differed in relation to sex, season, and human activity level.