Pest plague threatens native birds

19:45, Jun 26 2014

The Department of Conservation is planning a 20,000-hectare 1080 drop in the Dart, Routeburn and Caples Valley to combat a pest plague and save dwindling native bird species.

During summer beech forests in the South Island seeded heavily - a process known as a "mast" - and department forecasts suggest extra seeds will cause rat and stoat numbers to soar.

In turn, once the seeds run out the predators turn to native birds, endemic species such as yellowhead, blue duck, kea and kaka.

The draft operational area includes 4000ha in the Caples valley, 6500ha in the Routeburn valley and 9400ha of the Dart valley. The department anticipates the operation in spring before the Great Walks season.

Department scientist Dr Graeme Elliot yesterday said the planned operation was the first such drop on a large scale to combat the effects of a "mega-mast."

"When there's a lot of seed on the ground the rats breed. The levels we have now here are indicating we've a problem coming. If the rats go apes ... we need to nail them."

The department previously used 1080 in the valleys but not since 2009. In 2011 there was beech mast in the Wakatipu and the department decided against 1080, but studies showed trapping alone was insufficient to deal with a predator spike after heavy seeding. About three-quarters of the yellowhead population in the Dart Valley was lost after the 2011 beech mast.

All affected parties will be consulted.

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The Southland Times