Patrick Garvey is likely to be a stoat’s worst nightmare, playing with their senses and imitating predators. Following on from his very successful initial research of two years ago, when he confirmed that stoats were fearful of physical predators, he’s taken the research up a notch and established that, curiously, the predator’s scent does not elicit the same response. In fact, he has shown that, in an odd juxtaposition, dominant predator scent is attractive to stoats!
Explaining the surprise result that stoats consume food at the ‘high risk’ (predator-scented) area first, he says predator odour must be a valuable source of information for a foraging stoat. Stoats may use predator odour to locate and scavenge the remains of prey left over by more dominant predators or it could be that stoats fortuitously discover food when investigating a threat.
Like the first phase of the study, this is a collaboration between researchers at the University of Auckland and Landcare Research, who tested the response of stoats to the scent of two of their dominant enemies - cats and ferrets. Previous trials by Patrick, a doctoral student in the School of Biological Sciences, found that stoats were clearly fearful in the physical presence of predators, using avoidance behaviours, increasing vigilance and reducing feeding.
“This gave us a clear indication of the nature of the relationships between these predators; stoats are dominated by both ferrets and cats,” he says. “The second trial was designed to test stoat responses to the odour of those predators. We had three foraging locations with prey of baby dead rat in each foraging area, but only one of the three foraging areas had the scent of a predator, cat or ferret.
“We were 100% convinced that stoats would avoid the high risk predator scent. I had envisaged wildlife managers using predator odour as a deterrent, as stoats are ferocious predators and prolific killers of native birdlife, including young kiwi chicks.
“However, what we discovered was attraction. Because we ran both trials with the same individuals, we could be sure that stoats recognised the scent as being from a dangerous predator, but were still attracted.”
Patrick is hoping his research could have wide-ranging conservation benefits. The ability of stoats and many other mammals to ‘eavesdrop’ on the olfactory communication system of larger predators could be the beginning of the search to develop odour ‘lures’ in pest trapping operations.
Patrick Garvey surmises that, if stoats in the wild also respond with increased attraction to predator odour, then adding dominant predator odour would increase trapping rates and improve the accuracy of population estimates.
“We have a provisional patent in place and, if the lure is effective in the wild, we would hope to make it available to trapping operations country wide.”
However, he says, the implications of the findings are even more exciting from a behaviour perspective as it may have applications in every biome on the planet where predators co-exist.