Utilising technology and community engagement to protect native birds

The battle against introduced pests in New Zealand has been ongoing for decades. Tipping the scales in this war is the introduction of technology and the use of species-specific target tools.

Te Whare Wānaka o Aoraki Lincoln University’s Professor James Ross has conducted extensive research in this area.

“The three target predators are possums, stoats and rats. In the past, we were losing the fight for the birds, particularly in braided rivers and native forests. Stoats and ship rats climb trees so birds in the canopy and on the ground were vulnerable.”

With the introduction of Predator Free 2050 in 2016, 18 landscape-scale projects covering 757,000 hectares are funded by the government through Predator Free Limited.

The Saving New Zealand’s Birds report published by the Parliamentary Commissioner for the Environment in 2017 highlighted the importance of this work as Professor Ross explains.

“Four out of five native bird species in New Zealand are endangered with some unable to be moved to offshore islands away from predators. That means managing populations on the mainland which has many challenges. For example, the captive breeding programme for black stilt releases up to 150 juvenile birds every year though the current population in the wild is less than 200 and not growing due to cats, ferrets and hedgehogs.”

The reality, says Professor Ross, is that offshore islands are no longer a solution to re-homing native birds with the land area totalling only 30,000 hectares and the habitat not matching mainland New Zealand. With non-occupied offshore islands no longer a solution, what next?

“We need to inform the public just how dire the situation is and educate them about predator control and the different tools used. A great example of community engagement is in support of Zealandia Te Māra a Tāne Wellington’s wildlife sanctuary. Initially, 140 households began backyard trapping, expanding to four suburbs totalling over 3,000 hectares. Miramar Peninsula in Wellington again is another example – the success of people’s backyard trapping for rats and mustelids allowed the reintroduction of little spotted kiwi.”

To inform the public of the biodiversity and native bird population gains from the Predator Free 2050 programme, Professor Ross says continued funding is needed.

“We need to quantify these gains and share them with the public. Currently, the focus is on pest removal with few resources for monitoring outcomes. Before I retire, I want to continue working in AI, measuring biodiversity and native bird populations.”

Achieving outcomes, such as a 300% increase in kaka on Waiheke Island, is thanks to the success of Predator Free 2050 and the huge leaps in trapping technology.

“We’ve gone from tracking tunnels and other simplistic methods to now using thermal cameras with AI. Traps are often set up in remote areas, so AI allows operators to be sent alerts when the trap is activated or requires maintenance. In the past 10 years, the technological development of trapping tools has been really exciting,” says Professor Ross.  

In recent research, by Pest Free Banks Peninsula, audio, visual and social lures were added to traps to see if the combination would increase catch rates. The audio lure produces sounds, with an aggressive possum sound found in previous research to be the most effective. LED lights display patterns and reflections while body odours from stoat bedding materials are social lures. 

“We tested lures in Banks Peninsula in areas with high and low possum populations. The trials showed audiovisual and social lures used in a trap were significantly more effective than the non-lured sites, doubling the number of possums caught. These are simple devices too, making them cost-effective and easy to attach. We’ve already had lots of interest from the predator-free sites.”

So, what does the future hold for Predator Free 2050? Professor Ross shares next steps are defending areas from reinvasion and expanding to control predators beyond possums, rodents and stoats.

“How do we eliminate rodents that live in many habitats and close to people using control tools that won’t adversely affect non-targets? An exciting project I have been involved with is formulating a rat-specific toxin. This product would be a real game changer. If we keep focusing on species-specific tools, the future looks bright.”

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