Behavioural and movement responses of a specialist arboreal folivore to rapid plantation harvesting operations in landscapes previously affected by fire

Rapid habitat loss in fragmented, fire-impacted landscapes can disrupt animal behaviour and compromise welfare, yet responses of forestry ecosystem specialists remain poorly understood. We quantified behavioural and spatial responses of 54 resident koalas ( Phascolarctos cinereus ) to rapid harvesting of high-density Eucalyptus globulus plantations on Kangaroo Island, South Australia, three years after the 2019–2020 Black Summer bushfires. Global Navigation Satellite System (GNSS) tracking data were used to classify movement states (resident, exploratory, and dispersal) via breakpoint analysis, and to model changes in activity, home range, dispersal, habitat use, and survival following harvest disturbance. Consistent with the hypothesis that sudden habitat loss disrupts established space use patterns, harvest onset triggered a shift from short-range residency to prolonged exploration, with dispersal occurring primarily after harvest completion. Mean distance travelled between points more than doubled following harvest completion (≈55 m to 114 m). Predicted dispersal probability increased from < 3% pre-harvest to ∼24% post-harvest. Despite increased movement distances, most koalas initially remained within trees left uncut due to their presence or remnant native habitat patches rather than relocating to surrounding unburnt native habitats. Dispersal initiation was not explained by age or sex but was significantly related to harvesting onset. All mortality occurred post-harvest, coinciding with peak movement and habitat contraction; koalas living deeper inside the plantation had a 2.3-fold higher mortality risk. These findings demonstrate that rapid plantation harvesting can induce a behavioural disruption, delayed dispersal, and elevated mortality in a species characterised by strong site fidelity. Maintaining edge-connected refuge habitats and limiting the spatial extent and rate of harvest may reduce the concentration of animals within shrinking refuge habitats, lower mortality risk, and support successful redistribution and dispersal into suitable habitat following disturbance.