Suman Sran

Doctor of Philosophy, (Conservation Biology)
Study Completed: 2019
College of Sciences


Thesis Title
Assessing the sustainability of anticoagulant-based rodent control for wildlife conservation in New Zealand

Read article at Massey Research Online: MRO icon

Brodifacoum is used extensively to control invasive rodents in New Zealand. However, there are concerns regarding its high persistence, potential poisoning of non-target species and risk of resistance emerging in rodents. Mrs Sran assessed the potential of brodifacoum resistance in ship rat and mouse populations captured from areas of known brodifacoum use history in the Wellington region and Palmerston North. Blood-clotting tests performed to assess brodifacoum resistance revealed widespread resistance in both rats and mice. Despite this evidence of anticoagulant resistance revealed by BCR tests, no mutations conferring anticoagulant resistance were found in rats. Similar screening of mice revealed a mutation, Tyr139Cys, known to cause full resistance to less potent anticoagulants, but only minor resistance is known to occur towards brodifacoum. Although brodifacoum is probably still effective for controlling rodents in New Zealand, the results show that continual use of brodifacoum may results in ineffectiveness in the longer term.

Professor Doug Armstrong
Dr Penny Fisher
Professor Brett Gartrell
Professor Steven Trewick