What pests are present?

Mustelids (stoats, ferrets and weasels), rats, possums, feral cats, hedgehogs, pigs and dogs all predate birds or their eggs and other native animals in Puketi.

Rats, possums, pigs, goats and mice consume the plants of the forest and compete with birds and other native wildlife for food.

All of these animals have been brought to New Zealand by humans.

Because of its diversity and warm climate, Puketi provides introduced mammals with a relatively abundant food supply all year. The seasonal and annual fluctuations of food supply that occur in southern New Zealand forests are much less noticeable – in Puketi it is almost like a “mast” year every year, and a high level of pest control must be maintained continuously.

Trapping

Since 2003 the Trust’s focus has been on the control of cats and mustelids within 5500 ha of Puketi Forest (the management area) and the control of rats and possums in a 650 ha core area within this. [See Map of the Management Area] Eradication of these predators from Puketi is not feasible at present, because it would not be practicable to fence the boundary of the forest and re-invasion cannot be prevented. Continuous control to levels that allow protected species to prosper must therefore be maintained.

The primary method of control adopted by the Trust is trapping. Bait stations are installed throughout the core area so that toxins can be used to supplement trapping for rat and possum control.

The ten stoat trap lines in Puketi Forest are an average length of 10 kilometres, a day’s work for a fit trapper. (S10, serviced by volunteers, is 6 kilometres long.) Trap lines within the core area are spaced 100 metres apart. Where possible, trap lines follow existing roads and tracks, but almost 160 kilometres of additional tracks have been cut.  Regular maintenance is required to clear tree falls and regrowth.

Trap types are shown in the table.  Mustelid traps are baited with salted possum meat during summer and eggs during autumn and winter. Cat traps are baited with fresh minced rabbit or possum meat. Rat and possum traps are baited with peanut butter or proprietary non-toxic lures from Connovation Ltd: Ferafeed 213 for rats and Ferafeed Smooth for possums. Stoat lines are serviced 12 times a year, every 6 weeks during winter and every 2 weeks during summer. Core area trap lines are serviced every 4 weeks (13 times a year).

Rosters of volunteers service trap lines S10, P1, P2, T7, T8 and the Puketi Scenic Reserve. The longer and more remote trap lines are beyond the capacity of regular volunteers and are serviced by contractors. Stoat line contractors are Kelly Coogan, and Don da Via.  The core area is divided into three contract areas, serviced by Rigel Cotman, and Christina Holvast. Most of Puketi is now closed to the public to reduce the risk of visitors introducing kauri dieback. The Trust’s volunteers and contractors are required to follow strict hygiene protocols.

Trap catch results are summarised on the Trapping Results page.

Supplementary Toxins

Initially, trapping alone controlled rats in the core area to the target level (less than 5% tracking), but after about four years the tracking index increased to 20-30%. Since 2012, rat trapping has been supplemented with a single annual pulse of Pindone cereal pellets in the bait stations.  Only small quantities of toxin are required because rat numbers are already substantially reduced by trapping.  300 grams of bait are placed in each internal bait station and 600 grams in perimeter stations.  Baits are checked and topped up if necessary 10 days later and all remaining bait is removed after two months.  At least half the bait put into bait stations is eventually recovered and carried out of the forest for safe disposal.

Pindone is put out during August – October to coincide with the start of the bird breeding season. Monitoring has confirmed that this is effective.