Back to all Back

DOC Fiordland Mast Response Operations 2016

Update: 13 October 2016
Aerial toxic phase of the Clinton-Eglinton Valleys Battle for our Birds Predator Control Operation will be taking place from midday tomorrow Friday 14th  October 2016 and continue Saturday 15th  October (if not competed on the Friday).


The Department Of Conservation has released details of the planned response to the predicted predator irruption this year, which DOC considers to be a major threat to native species.
During spring, a significant beech tree flowering event was witnessed on the shores of Lake Te Anau, with clouds of beech pollen spreading across the landscape. For the Department, heavy beech flowering is forewarning of a beech seed mast event. Further monitoring has confirmed a major mast event throughout Fiordland, and over much of the South Island beech forests. Beech mast typically leads to a significant increase in rodent numbers within our forests which in turn leads to significant increases in stoat numbers. DOC monitoring indicates that this mast will be very heavy in Fiordland, more so than in 2014, so expect plague proportions of rodents and stoats.

Fiordland is home to a range of nationally significant threatened native species, particularly vulnerable to these predator irruption events: long and short tailed bats in the Eglinton and Iris Burn; whio/blue duck in the Clinton, Arthur, Sinbad and Cleddau; mohua in the Grebe Valley; kaka in Waitutu & Eglinton; and kiwi, kea, rock wren and kakariki at several sites. In the past, when significant mast events and subsequent predator irruptions occurred and no predator control was carried out, threatened species populations experienced catastrophic declines to the extent that local extinctions occurred.
To protect at risk native species, the Department is planning to carry out predator control at several sites within Fiordland National Park this spring/summer. The operation will be undertaken similar to the Department’s 2014 Battle for our Birds operation, and will involve aerially applied 1080 cereal pellets to control rodents and stoats. Sites controlled in 2014 will be controlled again, along with four additional sites. A factsheet outlining Fiordland District operations which contain indicative maps which provide further background is attached to this article.
The outcome monitoring after the 2014 operation was impressive:

  •  The productivity of whio/blue duck observed in the Clinton and Iris burn catchments was the best recorded to date with every known pair nesting successfully to produce ducklings.
  • No reduction in long or short tailed bat abundance in the Eglinton.
  • Increase in bat abundance in the Iris Burn.
  • Record numbers of robins and kaka in Waitutu.
  • Concessionaires reported a significant increase in bird abundance in the Clinton and Iris Burn
  • Significant increase in general forest bird abundance in the lower Hollyford.

Further details of the outcome monitoring results for the 2014 Battle for our Birds can be found online at this link:
Further questions, comments or enquiries can be directed to:

Emmanuel Oyston

Senior Ranger Biodiversity operations

Fiordland District
Department of Conservation – Te Papa Atawhai

[email protected]

NZAC Fiordland factsheet

Posted: 19/05/16

Posted By: Keith Gilby