Grain, pellet and wax block bait take by the house mouse (Mus musculus) and non-target species: implications for mouse eradications on coral cay islands.

Introduced rodents have been eradicated from large numbers of offshore islands using toxic baits; however, toxic baits have been linked with negative impacts on non-target species. The present study assessed the bait take of target (house mouse, Mus musculus) and non-target (buff banded rail, Rallus philippensis) animals on Northwest and Heron Islands in the Great Barrier Reef. Three non-toxic bait formulations (wax block, pellet and grain) were tested and each was applied at 1 kg ha(-1) in six treatment grids. The tracks of animals visiting the baits were identified using 30 tracking stations per treatment grid. A tracking station consisted of a track-board placed in the centre of a sand-pad. Mean bait take differed significantly between the formulations: birds took more grain bait than wax block bait; mice took more wax block than grain bait. Both mice and birds were equally selective of pellet bait. Thus, the findings indicate that wax blocks are the most suitable formulation for future baiting programs to eradicate mice on these and other islands.