Kokako chicks hatch in the Hunuas

Monday, 7 March 2016

Dozens of kokako chicks have hatched in the Hunua Ranges this summer.

That's being chalked up as a major victory for Auckland Council's biggest ever pest control operation and for the endangered bird.

A report on last year's aerial 1080 drops shows rats and possums have been all but been wiped out in the ranges.

Council regional strategy and policy committee chairman councillor George Wood says the 'extremely promising species monitoring results' are heartening.

'A little over a year ago we had a huge problem; the Hunua Ranges were teeming with rats and possums and our bird populations were being so heavily predated that no kokako were fledging and adult birds were being attacked,' he says.

'This well-executed programme saw the very fast knock-down of pest animals and similarly quick recovery of our treasured species.'

Council biodiversity Manager Rachel Kelleher says pest animals are at an all-time low with rats and possums significantly reduced in the ranges.

'When we began, rats were tracking at 91.6 per cent saturation across the ranges and possum numbers were high,' ' Kelleher says.

'Post-operational monitoring has been extremely positive. Pest species have dropped dramatically with possums tracking between 0.25 per cent and 1 per cent, and rat densities between zero and 1.03 per cent.

'Species monitoring is also a strong indicator of success and we have had 13 kokako chicks fledging from six monitored pairs so far and some of these pairs are already nesting again.

'With this high success rate among the six monitored pairs, we estimate there could be more than 100 fledglings from the 55 pairs in the managed area.

'Hochstetter's frogs are still present, vegetation is recovering and we are about to undertake long-tailed bat surveys.'

During the aerial operation, hundreds of samples were taken from reservoirs supplying Auckland's drinking water before they were returned to service. No 1080 was found in the water.

The report says further range-wide pest control using 1080 will likely be needed to maintain the 2015 operation's gains. But because of the success of the aerial operation no further possum control is planned for the Hunuas until winter 2017.