Variety is the killer of life when it comes to stoats.
Rabbit meat is the standard bait used by trappers to catch mammalian predators, but research published this week suggests more stoats could be caught in alpine areas if a variety of baits and traps was used.
Fiordland Department of Conservation senior ranger and lead researcher Jamie McAulay analysed stoat carcasses caught above Nelson Lakes National Park in the Tasman district, Mt Aspiring National Park in Otago and Fiordland National Park in Southland over an eight-month period in 2016.
Working with scientists from the University of Otago, Doc and Landcare Research, Mr McAulay found ship rats were stoats’ favourite food.
"Stoats are just like little death machines — their hearts beat at 180 beats per minute.
"Rats are their primary food source for the simple reason they are juicy and the most energy rewarding."
Native birds, lizards and invertebrates were most at risk from stoats when rats were absent from the environment, but not all stoats ate the same prey, he said.
"We found some stoats would turn to birds and others focused only on lizards.
"Collectively as a group stoats eat a wide range of prey, but each stoat has its own dietary niche."
The results of his research could be used by trappers in alpine areas to increase the overall probability of capturing stoats, he said.
"Current best practice for stoat bait is to use a block of rabbit meat and that is because on the lowland stoats eat rabbits, but there are no rabbits in alpine zones.
"Using alternative trapping lures or baits such as rat meat, and a variety of different traps, would meet the individual tastes of stoats and achieve better outcomes for our native species."
