The relationship between Rattus rattus trap capture rates and microhabitat in Mt Aspiring National Park

The role of vegetation in the relationship between microhabitat and ship rat (Rattus rattus) distribution remains poorly understood. We used three years of trapping data (2017–2020) to calculate capture rates for 97 traps in the Makarora Valley and Haast Pass areas of Mt Aspiring National Park and determined aspects of the vegetation surrounding traps that influenced capture rates. The presence of fruiting understory plants—round-leaved coprosma (Coprosma rotundifolia), horopito (Pseudowintera colorata), and wineberry (Aristotelia serrata)—had weakly significant and positive associations with rat captures, whereas increasing density of large (> 200 mm DBH) mountain beech (Fuscospora cliffortioides) trees had a negative association, which was highly significant. Future research should incorporate methodology that links seasonal food abundances to capture rates and explores the influence of edge effects.