Rattus rattus

Managers of ecosanctuaries often need to make decisions in the face of uncertainty. Model-based tools which aim to assist this process, for example proof-of-absence models, are underpinned by assumptions about the behaviour of target animals, including their spatial movements. In some cases, however, there are few empirical data to draw on to inform these models. The movement behaviour of individual pests in low-density environments, as well as the dispersal of juveniles away from their natal location, is poorly understood for many species, including the ship rat (Rattus rattus).

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.

Accurate determination of animal diets is difficult. Methods such as molecular barcoding or metagenomics offer a promising approach allowing quantitative and sensitive detection of different taxa. Here we show that rapid and inexpensive quantification of animal, plant, and fungal content from stomach contents is possible through metagenomic sequencing with the portable Oxford Nanopore Technologies (ONT) MinION. Using an amplification-free approach, we profile the stomach contents from 24 wild-caught rats.

Understanding rates of reinvasion is critical for determining what drives ship rat population recovery following large-scale control operations. We radio-tracked 23 adult ship rats on the edge of a forested area where rats had been suppressed by aerial compound 1080 in the Hollyford Valley, Fiordland. Eleven individuals died within two months of collaring and two individuals were never detected again, leaving us with data from 10 rats.