Zealandia ecosanctuary in Wellington has found predator tracks inside their boundary triggering a hunt for the predator.

The mustelid tracks, likely from a weasel, were spotted on Monday morning.

Conservation and Research Manager Dr Danielle Shanahan said they were searching the entire boundary for any holes.

ZEALANDIA A tracking tunnel result provided by Zealandia of the supposed mustelid which is loose in the sanctuary. The tracks show the animal walked through ink and left foot prints on paper. The print shows mustelid prints on the left, and on the right, some tracks left behind by a wētā in the same tunnel.

"We have spent the last day carrying out a thorough assessment of the fence to ensure there are no breaches, and put out camera traps to see if we can gain any more knowledge on the animal."

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Shanahan said the fence design was still incredibly effective, and the last incident of an unwanted entry was over 10 years ago.

ROB SUISTED/SUPPLIED Zealandia is considered the world's first fully-fenced urban ecosanctuary, but a predator has got in.

The tracks were found at the southern tip of the valley, and a team of staff and volunteers are now laying traps and tracking tunnels across the sanctuary to catch the intruder.

Zealandia is considered a world-first sanctuary – mustelids have not been found there for about 10 years.

Shanahan said they hadn't found any issues with the fence yet.

MATT DUNCAN/STUFF Zealandia is considered a world-first sanctuary with a predator exclusion fence - mustelids have not been found there for about 10 years.

"There are no obvious major holes. We are doing a very thorough check of the entire 8.6km boundary as we speak."

The fence was already checked on a weekly basis.

Zealandia didn't believe the incident meant other predators could be getting inside, she said.

"We are checking the fence for even the tiniest hole just to be sure. We are also laying enough traps to ensure that we capture any unwanted intruders."

The footprints were discovered during a routine annual pest audit in a tracking tunnel.

The prints prompted an immediate incursion response by Zealandia staff, supported by organisations including the Department of Conservation, Greater Wellington Regional Council, and Predator Free Wellington.









Shanahan said that while it was too soon to be certain how the mustelid gained entry, but it was likely to be a recent arrival.



"A Department of Conservation mustelid-detection dog swept the valley in late June, and found nothing."



The operation would continue until the animal was found.



"Even one introduced predator is one too many".

A single stoat, weasel, rat or possum could cause significant harm to birds, lizards and invertebrates.



Zealandia is a 225-hectare ecosanctuary in urban Wellington.

Since it was fenced in 1999 and introduced predators eradicated, it has reintroduced 20 species of native wildlife back into the area, including six extinct on mainland New Zealand for over a century.