title: Differential population responses of native and alien rodents to an invasive predator, habitat alteration and plant masting.
abstract: Invasive species and anthropogenic habitat alteration are major drivers of biodiversity loss. When multiple invasive species occupy different trophic levels, removing an invasive predator might cause unexpected outcomes owing to complex interactions among native and non-native prey. Moreover, external factors such as habitat alteration and resource availability can affect such dynamics. We hypothesized that native and non-native prey respond differently to an invasive predator, habitat alteration and bottom-up effects. To test the hypothesis, we used Bayesian state-space modelling to analyse 8-year data on the spatio-temporal patterns of two endemic rat species and the non-native black rat in response to the continual removal of the invasive small Indian mongoose on Amami Island, Japan. Despite low reproductive potentials, the endemic rats recovered better after mongoose removal than did the black rat. The endemic species appeared to be vulnerable to predation by mongooses, whose eradication increased the abundances of the endemic rats, but not of the black rat. Habitat alteration increased the black rat's carrying capacity, but decreased those of the endemic species. We propose that spatio-temporal monitoring data from eradication programmes will clarify the underlying ecological impacts of land-use change and invasive species, and will be useful for future habitat management.
authors.affiliation: Center for Environmental Biology and Ecosystem, National Institute for Environmental Studies, , 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan, Graduate School of Agricultural and Life Sciences, University of Tokyo, , 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan, Japan Wildlife Research Center, , 3-3-7 Kotobashi, Sumida-ku, Tokyo 130-8606, Japan, Biodiversity Center of Japan, Ministry of the Environment, , 5597-1 Kenmarubi, Kamiyoshida, Fujiyoshida, Yamanashi 403-0005, Japan, Naha Nature Conservation Office, Ministry of the Environment, , Okinawa Tsukansha Building 4F, 5-21 Yamashita-cho, Naha, Okinawa 900-0027, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Fukasawa
authors.forename: Tadashi
authors.initials: T
authors.lastname: Miyashita
authors.forename: Takuma
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Masaya
authors.initials: M
authors.lastname: Tatara
authors.forename: Shintaro
authors.initials: S
authors.lastname: Abe
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D044822:Biodiversity; D017753:Ecosystem; D008988:Herpestidae / Q000502:physiology*; D058865:Introduced Species; D008954:Models, Biological; D011156:Population Density; D011157:Population Dynamics; D051381:Rats / Q000502:physiology*
keywords: Amami Island; Bayesian state-space model; bottom-up effect; mesopredator release; predator–prey interaction; top-down effect