title: Seasonal and Diel Activity Patterns of Eight Sympatric Mammals in Northern Japan Revealed by an Intensive Camera-Trap Survey.
abstract: The activity patterns of mammals are generally categorized as nocturnal, diurnal, crepuscular (active at twilight), and cathemeral (active throughout the day). These patterns are highly variable across regions and seasons even within the same species. However, quantitative data is still lacking, particularly for sympatric species. We monitored the seasonal and diel activity patterns of terrestrial mammals in Hokkaido, Japan. Through an intensive camera-trap survey a total of 13,279 capture events were recorded from eight mammals over 20,344 camera-trap days, i.e., two years. Diel activity patterns were clearly divided into four categories: diurnal (Eurasian red squirrels), nocturnal (raccoon dogs and raccoons), crepuscular (sika deer and mountain hares), and cathemeral (Japanese martens, red foxes, and brown bears). Some crepuscular and cathemeral mammals shifted activity peaks across seasons. Particularly, sika deer changed peaks from twilight during spring-autumn to day-time in winter, possibly because of thermal constraints. Japanese martens were cathemeral during winter-summer, but nocturnal in autumn. We found no clear indication of predator-prey and competitive interactions, suggesting that animal densities are not very high or temporal niche partitioning is absent among the target species. This long-term camera-trap survey was highly cost-effective and provided one of the most detailed seasonal and diel activity patterns in multiple sympatric mammals under natural conditions.
authors.affiliation: Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ikeda
authors.affiliation: Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Uchida
authors.affiliation: Hokkaido Research Center, Forestry and Forest Products Research Institute, Sapporo, Hokkaido, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Matsuura
authors.affiliation: Kansai Research Center, Forestry and Forest Products Research Institute, Kyoto, Kyoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Wildlife Management Laboratory, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Laboratory of Wildlife Management, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Kaji
authors.affiliation: Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido, Japan.|Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Itsuro
authors.initials: I
authors.lastname: Koizumi
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D007564:Japan; D008322:Mammals / Q000502:physiology*; D012621:Seasons; D014741:Video Recording