Aotearoa’s first entirely natural, cost effective long-life lure

November 4, 2021 3:37 pm

There’s a fair dose of Kiwi can-do in research to develop a new long-life lure targeting rats, possums and mustelids. The research has borne fruit despite the interference of Covid lockdowns, and produced some unexpected bonus outcomes.

Boffa Miskell biosecurity consultant Dr Helen Blackie set out to develop a long-life lure that would increase the efficiency and cost-effectiveness of predator trapping. The outcome is a real “New Zealand Inc” product that is 100% natural, non-toxic and the only lure available with solid science and extensive field trial results behind it that prove it remains effective for months, even in extreme weather conditions. The lures are called PoaUku, which translates to ‘clay lure’.

“Mould is a big issue with many of the lures currently available – a lot will go mouldy in a week or two, especially in the challenging environments we’re working in. If you don’t have to rebait the trap every couple of weeks, things are a whole lot more efficient, money and people-wise. We also found over three months the lures got significantly more attractive – the longer they were out, the more attractive they became to pests such as rats and ferrets,” Helen says.

“We came up with a clear winner for rats, and then tested to see how long rats were attracted to it for. Over three months the lures got significantly more attractive – the longer they were out, the more rats liked them, and at every stage they were substantially more attractive than fresh peanut butter. At three months we got our best result. The same lure also works for possums.

“The other thing that’s interesting for the rat stuff is we know that rats are repelled by strong scents. We always think about these things in a human way – if we can smell it then they will too, but the more subtle scents are what they’re attracted to.

Identification of the best mustelid scent saw four different options trialled at “mustelid cafes” out in the bush.

“We did trials throughout New Zealand looking at which they chose first, which one they spent the most time investigating. We got this great footage of stoats and ferrets trying to eat the lure blocks and it was fascinating to watch the choices they made.

“Mustelids also had a clear preference for a certain lure, and ferrets had the highest interactions with it after more than three months in the field.

“We had the same thing with the ferrets that we observed with the rats – it continued to get more attractive over time for the ferrets and we had the best interactions with it at month three-plus. It was a flat-out winner for the ferrets – they went straight for our lure.

“Surprisingly, one of the mustelid trial scents was hugely popular with rats, as well as possums and hedgehogs. Mustelids liked it, but the rats were going nuts for it, and the other pests were highly attracted to it too, making it truly multi-species. This lure which we originally designed specifically for mustelids had over 1000 rat interactions – three-and-a-half times more than peanut butter did. In the real world where you’re trying to catch pests, if you can catch three times as many, that’s a big difference”.

The result is an entirely natural, cost-effective product – despite difficulties posed by the Covid pandemic.

“We had to develop a cost-effective product but if the process is expensive, that doesn’t work either and we didn’t want to delve into that artificial scent realm either because animals can totally tell the difference. A rat’s sense of smell is extraordinary compared to a human’s, which is why they can be used to detect things like landmines.

“When we started this project, Covid wasn’t even on the horizon. We were based in Auckland and effectively locked out of the field trials we were running throughout New Zealand. We had staff unable to travel or do fieldwork. Getting stuff in from overseas was really hard – we couldn’t source raw ingredients, and they increased substantially in price or there were significant delays.

“We’ve ultimately done everything with New Zealand companies. We’ve had to do a whole lot more work working out how we’re going to source things domestically, but if you can make a product in New Zealand from New Zealand suppliers and ingredients keeping it local is a far superior option at the moment, and good for those companies as well,” Helen says.

The PoaUku lures are now commercially available via Connovation Ltd, initially in two scent options but with another multi-species lure on the horizon. Future work also involves customising the size and shape of the lures for more specific trap designs.

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