Reviewed: 15 January 2015
DOC plans to continue possum and rodent control in the Manawatu Gorge Scenic Reserve (southern side), Woodville Ferry Reserve and adjoining private land (see map).
The pesticide used to control possums in these areas has the brand name Feratox, in two forms. The first is 18 g 'Strikers' which are a biodegradable potato starch bait station containing rat repellent. These will be stapled to trees and will be used to reduce the initially high possum numbers. The second form is Feratox Hard Blocks containing pea sized pellets of encapsulated cyanide contained within 12 g green pre-feed blocks. Up to 5 blocks will be placed in existing white bait stations, which are attached to trees on a grid, perimeter and ridge system throughout the reserve to maintain possums at low levels. Feratox will not be placed within 150 m of any household or within 20 m of public walking tracks.
The pesticide used to control rats in this area is Diphacinone (brand names Pestoff Rodent Bait 50D‘). Baits are dyed blue and are in the form of 10 mm diameter cylindrical pellets. 1 kg of pellets will be placed in bait stations alongside Feratox Hard blocks.
This is an ongoing operation, with bait placed in bait stations throughout the year.
The pesticides, cyanide and diphacinone, are poisonous to humans and domestic animals; poisoning can occur through handling or eating the bait, or consuming dead or poisoned animals. Treat all baits as poisonous.
Animal carcasses will remain poisonous until they have decomposed. There is no health risk in using this area if these rules are observed:
- do not handle any bait
- do not allow children to wander unsupervised
- do not bring dogs into this area
- do not handle or eat animals from this area.
Why we are controlling possums and rats
This operation is part of the ongoing Manawatu Gorge Biodiversity partnership which aims to improve the biodiversity, scenic and recreational values of the Manawatu Gorge. The Manawatu Gorge is a hotspot for native plant and animal biodiversity. Several rare and endangered species are found in this area, such as kaka, kakariki, giant maiden hair fern and rata.
Native bird species depend on native trees for their food supply. Possums and rats eat seeds and seedlings, impact on forest regeneration, compete with native wildlife for food and directly prey on birds, eggs and insects.
This operation will provide improved habitat and decreased native bird predation.
Why we are using this method
We have found poison baiting a very effective form of possum and rodent control. Feratox (encapsulated cyanide), is an excellent tool for knocking possum numbers down quickly.
Pestoff Rodent Bait 50D (diphacinone) is effective for controlling rats. Because of its slow acting nature, no bait shyness is experienced by target animals.
The use of the pesticide, cyanide, requires consent from the Medical Officer of Health. DOC also has an internal approval process to ensure the operation is meeting our quality management standards for pesticide use.
This approval entails a detailed assessment of risks involved in the work. The document produced for this exercise is called an Assessment of Environmental Effects, and a copy for this operation can be obtained from the DOC office in Palmerston North. We have informed people most affected by this operation before finalising operational details.
If you suspect poisoning
- Palmerston North Hospital, phone + 64 6 356 9169
- National Poisons Centre, phone +64 800 764 766 (0800 POISON).
- In the case of a domestic animal being poisoned contact a local veterinary service.
Map of pest control area