An area of 6300ha of public conservation land in the Otahu catchment near Whiritoa will have a 1080 operation.
Starting this month, the aerial pest control is part of the government's nationwide 'Battle for our Birds' 1080 operation.
Otahu is largely forested, and drained by the Otahu River and tributaries to the Otahu estuary, which covers about 110ha providing significant vegetation and wildlife habitat.