Hamilton City Council controls and monitors predators throughout the city. Conventional monitoring is labour intensive and expensive, and the results are variable for urban restoration areas. Recently the council has invested in DOC AI Cams to reduce the monitoring cost and significantly improve monitoring, helping protect endangered and recovering species in the city.

The DOC AI Cams are thermal cameras and audio bird monitors. The thermal camera is more sensitive trail cameras and can easily see animals as small as mice and weasels at night. The cameras are connected to the internet and use AI to automatically identify the animals.  This saves labour in analysing the recordings and provides real time monitoring. In addition, the cameras record audio and automatically identify over 60 birds.

An example of the information automatically created by the DOC AI Cam

The technology was developed by The Cacophony Project and funded by the Department of Conservation through the Tools to Market fund. The cameras are manufactured and sold by 2040 Limited.

Seeing more predators

In one site the council historically used tracking tunnels and chew cards. Recent monitoring with these over three nights showed just a few locations with mice only. One camera on the site showed that they were missing rats, hedgehogs, possums and cats. Here’s an example of the sort of footage caught.

Fraser Smith, Predator Control Advisor is managing the rollout.

 “Monitoring is critical to getting the predator management optimised and for showing evidence of the results achieved for the resources applied. The cameras mean that we can do much more of it with better granularity and at a lower cost per site.”

“I have cameras in a few locations just to understand what is there as a base line and also to see what we are missing with current tracking and control methods. “

The camera observations have provided the impetus to change up what the council is doing at one location in particular where the historic approach of night shoots for possums/rabbits and tunnel traps for rats has shown to be only scratching the surface. The first change was to put possum kill traps out and one month later they have removed 55 possums. They are also about to start their first pulse of toxin for rats as clearly trapping alone was clearly not delivering the result. This site is holding kākā beyond a few winter months (a first for Kirikirroa in living memory) so doing everything to make them safe and promote nesting is a high priority.

Here is an example of a Kākā call recorded by the camera.

Protecting Skinks from hedgehogs

At another site, rodents are well controlled, but the thermal camera showed they are missing too many hedgehogs. As a result of these observations, they have now widened DOC traps to 80mm entrances. Hedgehog control is particularly important as there is a known remnant population of ornate skinks at this site which are particularly vulnerable to hedgehog predation.

Informed cat policy 

Cats appear at every site, regardless of distance from housing. Fraser is compiling footage to enable fact-based council discussions on cat management in the city. This is a sensitive nationwide issue balancing pet ownership with feral-cat impacts on native wildlife.

Bird recovery as the ultimate KPI

Bird monitoring provided by the cameras will be a key signal as to whether the council is achieving the end results with increases in bird numbers and biodiversity over time, something that if done right they will have a high degree of confidence with quantitative evidence. HCC recorded bellbird/korimako calls this spring despite no visual sightings – bellbirds remain rare visitors to Hamilton. Long-term increases in bird detections will confirm predator-control success.

Fraser again: 

“I have a growing list of questions that we can answer with the thermal cameras so that we can optimise what we are doing with predator management. I view the thermal cameras as a very cost effective way to get quality insight and improve the way we are approaching predator management.”