The Department of Conservation completed its Battle for our Birds aerial 1080 pest control operation in the Iris Burn valley in Fiordland National Park yesterday.
The Iris Burn operation aims to protect native wildlife such as the critically endangered long-tailed bat, whio/blue duck, kākā, and Fiordland tokoeka kiwi from rising numbers of rats and stoats.
The application of biodegradable 1080-laced cereal baits over 11,200 hectares in the Iris Burn valley and adjacent areas, including alongside Lake Manapouri, follows treatment of the area with non-toxic “pre-feed” bait a week ago.
The operation followed stringent safety procedures and buffer zones were in place around significant waterways such as the Iris Burn River and Lake Manapouri, and huts on the Kepler track.
DOC rangers have inspected and cleared tracks within the treatment area, which were closed while the operation was underway.
Warning signs advising the public about the dangers of the pesticide are in place at the main entrance points to the Kepler Track and boundary of the operation area.
For more information on DOC’s Battle for our Birds pest control response see: www.doc.govt.nz/battleforourbirds
The Iris Burn pest control area is home to a number of species vulnerable to predation by rats, possums and stoats, including long-tailed bat/pekapeka, whio/blue duck, mōhua/yellowhead, Fiordland tokoeka kiwi, kea and kākā.
Aerial 1080 is an effective method of knocking down plague levels of rats and stoats (by secondary poisoning) following a beech mast (seeding), and also possums, before they overwhelm native birds and bats, which are particularly vulnerable during the breeding season and when roosting in holes in trees.
The pest control operation has two separate phases—the sowing of non toxic “pre-feed” bait, followed by biodegradable poison 1080-laced cereal baits at least five days later.
The 1080-laced cereal baits are sown at a rate of 2 kilograms per hectare using GPS-guided feeder systems. The poison content of this bait is 3 grams per hectare.
The operation will not affect the opening of the Great Walk season on the Kepler Track in October.
Monitoring the effects of the pest control operation will be undertaken in coming weeks including the knock-down of rats. Rat-vulnerable forest birds such as robins, riflemen and tomtits will be monitored in the treatment area and a nearby non-treatment area to assess effectiveness of the pest control operation. There is also ongoing monitoring of long-tailed bats in the valley.
The Iris Burn operation is one of 22 confirmed Battle for our Birds operations that will use aerially applied 1080 over about 600,000 hectares of conservation land to knock down rising predator numbers fuelled by unusually heavy seeding in South Island beech forests.
The coordinated Battle for our Birds pest control programme is targeted to protect the most at-risk populations of mōhua/yellowhead, kākāriki/parakeet, kiwi, whio/blue duck, kea, kākā, rock wren, giant land snails and native bats at sites across the South Island.