Predator Control

Photo by Laurence Bechet

Here in Aotearoa/New Zealand we are working to restore the balance from the damage that introduced predators cause to our native plants and animals.

The Ark has run baiting and trapping programmes since 2002, adapting methods and learning as we go, and as our environment changes.


Baiting is the core work of most of our volunteers, for most of the time.

Our 4,785 bait stations are placed on a 50 x 100 metre grid across our 2270 hectare area. These are baited twice or more per year, guided by bait uptake and rat monitoring data. It takes around 16 weeks to carry out a complete baiting round across the entire project area.

While working on bait lines, volunteers record information as they go on how much bait has been eaten, known as ‘bait uptake’. This guides our next baiting round and choice of toxin.

This map shows the latest bait uptake for the Ark.

Toxin choice

Much of our bait is supplied by the landowner Auckland Council. We have a range of toxins in our toolkit for rotation, to suit particular criteria.


Trapping is equally important as baiting, and targets mustelids (stoats, weasels and ferrets) as well as possums.

The Ark has a trapping network which is added to and adapted as new traps and lures are developed.

DOC 200

Targets stoats. Also catches weasels, ferrets, and rats as a bonus. The Ark has 330 in use.

Possum box trap

Sometimes known as a Timms Trap. Targets possums. The Ark has 126 in use. 

Goodnature A24

Self-resetting trap. Targets rats and stoats. The Ark has 70 in use.

Modified Victor

Targets rats and stoats. Used to provide extra protection to robin or kōkako nests that are being monitored.


Steve Allan Traps

Targets feral cats. The Ark has 30 in use.

Wasp control

Wasps often rise to high numbers in the Waitākere Ranges late summer and autumn, posing a threat to our native invertebrate populations, nesting birds and ourselves as we work in the bush. In 2016 and 2017 use of Vespex was trialled, which was summarised in this report (PDF).

Recording our catches

Trappers record their catches in a programme called CatchIT. This also allows analysis of which sites are the most important for trapping predators, as well as how traps are performing and whether some may require attention. 

Catches from 2019 Nov-Dec are shown in this map, which includes all species recorded. Click to enlarge. 

Ark in the Park is located in the Waitākere Ranges, which are currently closed to minimise the spread of kauri dieback disease.