Alright. Kia ora ko Jamie McAulay tēnei. This is a video abstract of our latest paper out in the New Zealand Journal of Ecology. Conservation programs around the world that are aiming to protect native fauna by controlling small invasive mammals generally assume that the removal of any one individual of a given species is gonna have the same effect as removal of another individual of the same species. So think a stoat is always a stoat right? But internationally within larger bodied carnivores, so think things like bears of wolves, there's actually quite a strong amount of variation at times in the amounts of different prey consumed by individuals of the same species. And the same idea's been touted in New Zealand. I call it the bad egg hypothesis. The idea that an individual predator might become sort of honed in on one prey type and be responsible for a large amount of the damage. But traditionally this has been a really challenging thing to study. You can't follow a stoat around with a notebook. Here we use a biochemical tool to assess the degree with which individual stoats become specialised within the dietary niche. So we assess the range of chemical signatures of isotopes and the the larger the chemical signatures pretty much tells us a little bit about the larger the range of prey items regularly consumed by that animal. The larger the dietary niche and we do this for three populations of stoats so for the dietary niche of the population as a whole but also for each individual stoat at three different sites in the alpine zone up up there, of three national parks in the South Island of New Zealand. And what we found was that at two sites at Fiordland and Mt Aspiring stoats had a relatively small and consistent dietary niche. Whereas at our other site at Nelson Lakes National Park they were exploiting a far wider range of of resources. But, and here's the kicker right? That each individual stoat wasn't eating a wider range of things. There was no significant difference between the the size of the dietary niche of individuals. It was just at the population level. So each individual specialising in different areas of the dietary niche, collectively expanding the buffet. Now rat abundance was inversely aligned with the size of the population niche. Dietary niche. And there was a bunch of other things that were different between our sites as well. But looking through the literature it allowed us to kinda form this theory that perhaps in this ecosystem rats are acting as the optimum dietary niche. So the core, the core prey. Primary prey. And that so when there's rats there stoats are eating rats and a little bit of these other things around the side. So a little bit of birds and lizards and invertebrates but the primary prey is rats. Whereas when those other primary prey are absent perhaps the stoats um the dietary niche expands with a whole lot of different stoats specialising in different areas of the dietary niche so it's kinda like this if there's if there's pizza at the party, we all eat pizza who doesn't love pizza like optimum party food we might nibble up the chips and things around the edge but really pizza where it's at, if there's no pizza at the party then you might eat the chips, I eat the celery sticks and Pete's on the cheese rolls. So we're all acting as individual specialists within a broader dietary niche. Each one of us is focusing on a smaller area but collectively we're eating a wider range of things. But why not a wider range of things? Why is each individual stoat still focusing on a small range of things when clearly as a species they could be eating a wide range of things and that's a really interesting question. It could be a whole lot of different drivers there. It could be a genetic thing. It could be size. Different stoats go for different size prey items. It could be say a boldness spectrum that some stoats take more risks than others. Or it could be due to what's called a limited prey recognition library, that there's sort of a really ideal number of things you can focus on in your mental sort search image and that above a certain number you become less efficient. But mainly we wanna know how do we use this information to better protect native species and I think physicologists if we can start to think not just about the numerical ecology of how many stoats are in the environment but also start to be thinking about the behavioral ecology of of what's happening within that environment and within that that stoat behaviour that will also affect the risk to native species and particularly we should be aware of when primary prey sources are absent that perhaps the the risk for secondary prey will will be elevated. We should all start thinking about the individual specialist. How does that knowledge that each individual state sometimes is acting as individual specialists affect how we do things and so perhaps some variation into things like trapping and baiting regimes wouldn't go on this. A massive amount of thanks goes to the people that have helped a really huge amount with this study. Literally Trappers put dead stoats in their packs and carried around for days and sent them to me in the mail. So this couldn't happen without you. And many other volunteers and other people who helped along the way. So cheers. The hope is that this research helps you do what you do better. We're always keen to hear comments and critics, criticisms, great and collaborations. The paper is online free and open source right now at the New Zealand Journal of Ecology website. So cheers. Happy trapping.