Gillian Dennis

Citation

Thesis Title
Minimising non-target impacts of anticoagulant rodenticide use for a highly susceptible species, the New Zealand lesser short-tailed bat (Mystacina tuberculata)

The use of anticoagulant rodenticides (poison baits) to manage rodent pests is essential for wildlife conservation, but also poses risks to threatened species. In 2009, more than 100 endemic lesser short-tailed bats died from rodenticide poisoning. Ms Dennis investigated the route of exposure to the poison and assessed the effectiveness of alternative baiting practices at minimising mortalities. She used modelling to examine the potential consequences of nontarget mortalities on bat population viability. Ms Dennis found that the likely route of exposure was contaminated arthropod prey. While revised management considerably reduced the risk of extensive bat mortalities it did not prevent exposure, which raised concerns about sublethal effects. Modelling highlighted the fine balance between managing vertebrate pests and protecting native species that are highly susceptible to vertebrate poisons. Ms Dennis recommended the use of less potent poisons in bat habitat and vigilant monitoring to ensure viability of exposed bat populations.

Supervisors
Professor Brett Gartrell
Professor Doug Armstrong