Invasive wilding pines can be hidden among other trees, but that’s not stopping efforts to spot them from the air.

The hunt for wilding pines around Lake Tekapo has entered a new phase, with drones helping crews track down individual trees that remain after years of successful control work.

Infestations of wilding pines — introduced species that can displace native species — across the Tekapo River area have been significantly reduced through ongoing control work. The focus has now shifted to finding and removing isolated trees that remain.

While small in number, these trees can still produce thousands of seeds and establish new infestations if left unchecked.

Toitū Te Whenua Land Information New Zealand (LINZ) is using drone technology to help spot these ‘needle in a haystack’ trees before they have a chance to spread.

Biosecurity Leader Tracey Burton says LINZ has already controlled most of the large wilding pine infestations on the land it manages in the area.

“The challenge now is finding and removing the scattered trees that remain,” said Burton.

“At this stage, every tree matters. These are often isolated trees hidden among other vegetation, and drones help us identify them quickly and accurately so they can be removed before they spread.”

A need to stay vigilant

At this time of year, wilding pines stand out clearly against nearby deciduous trees, making them easier to identify from the air.

The drone imagery is then used to guide ground crews directly to the trees, reducing time spent searching and allowing control work to be carried out more efficiently.

While significant progress has been made, Burton says the work is far from over.

“Wilding pine control doesn’t stop once the big infestations have been removed. New seedlings and scattered trees will continue to appear, so ongoing surveillance and follow-up control are essential,” she says.

“That’s how we protect the gains already made.

“The good news is we’re now hunting individual trees in this area rather than tackling large infestations. That’s a sign of how much progress has been made, but we’ll need to stay vigilant to keep it that way.”

The drone work, carried out by Boffa Miskell and Trap and Trigger, complements wider wilding pine control efforts across the Mackenzie Basin, with Environment Canterbury and the National Wilding Conifer Control Programme undertaking work on neighbouring properties.

Together, these efforts are helping protect Mackenize District’s iconic landscapes, productive land and unique environment from the spread of wilding conifers.