Immigration drives ship rat population irruptions in marginal high‐elevation habitat in response to pulsed resources

Pest animal populations, such as rodents, often irrupt in response to pulsed resources. However, few studies have considered how understanding the propagation of irruptions across landscapes could lead more efficient pest suppression. Resource pulses might create temporary source–sink dynamics heterogeneous environments, whereby reservoirs animals living high-quality habitat increase and spill over into marginal habitat. Low-density populations also through situ breeding by residents increased food availability. Understanding relative importance these two nonmutually exclusive processes is important outbreaks potentially be efficiently controlled targeting source early an outbreak. We used a Bayesian hierarchical model estimate density-dependent emigration from lower elevation habitats versus resident population growth invasive ship rats (Rattus rattus) marginal, high during resource event (beech seed mast). found that elevations was for facilitating rapid at elevations, enabling reach peak densities 10.6 ha−1. Without immigration, were predicted only 1.8 ha−1 elevation, given their when we started monitoring (0.6 ha−1). This result suggests rat control targets low mid-elevations may sufficient suppress high-elevation if effectively prevents immigration. Our study spillover higher quality enable rapidly propagate landscapes. r-selected taxa even very can significantly occur, albeit than