Hunua Ranges Flora Recovering After Mass 1080 Drop Earlier in the Year

Recovery under way

Also Update on kōkako with a pair spotted nesting


From Auckland Council

Forest flourishes following Hunua pest blitz

Flourishing foliage, an abundance of seeds and forest ‘fruit’ and signs of new life in the kōkako population are the first signs of a successful pest control programme in the Hunua Ranges this year.

The first round of post-operational monitoring, following the aerial application of 1080 over a 21,500-hectare area, is complete, with rat and possum numbers at an all-time low.

Biodiversity manager and operational lead for the project Rachel Kelleher says the latest results are significantly lower than the possum and rat targets set for the project.

“The target set for this operation for possums across the whole treatment area and rats within the intensively pest controlled kōkako management areas (KMA) was to get densities below five per cent. This means that fewer than five possums would be caught, or fewer than five tracking tunnels would have rat footprints, for every 100 trap or tunnel nights.

“We are delighted to report the results for possums was 0.65 per cent and 1.03 per cent for rats – significantly lower than our target!

“This is a significant reduction in both pest species but particularly rats, which were tracking at 91.6 per cent ahead of the operation,” she says.

Within the 1150-hectare kōkako management area, which has been monitored twice since the first bait application in August, no rats or mice have been recorded on either occasion in any of the 100 tracking tunnels.


Councillor George Wood, chair of the Regional Strategy and Policy Committee which lead the change to pest management methodology in this area, says council is extremely pleased with the outcome of the programme.

“It was a courageous decision to go for a 1080-based approach to targeting pests in the Hunua Ranges, and it was the right one.

“Last October, councillors were presented with a very dire predicament for our largest mainland forest and they took the time to understand the science, weigh up the consequences and make an informed decision.

“Using any pest control toxin requires careful consideration and robust operational planning. 1080 is not the only tool we have for fighting pests but, right now, it is the most effective way to prevent wholesale destruction of treasured flora and fauna,” he says.

Councillor Wood also acknowledges the collaboration with mana whenua on this operation.

“The Hunua Ranges and Kohukohunui are extremely important to seven iwi with tribal ties to this area. We have a common goal – of protecting this forest – and greatly appreciate the opportunity to work side-by-side on the kaitiakitanga of the ranges,” he says.

Franklin ward councillor Bill Cashmore acknowledges the role that the community has played in this operation.

“Whilst not everyone supported this approach, we appreciated people’s patience, interest and preparedness to work with us.

“Around 3,000 hectares of private land was included, ensuring the operation could stretch to adjoining bush areas and prevent the threat of reinvasion as well as helping out with pest management on local properties.

“Many residents are already reporting lower pest numbers and, like me, are looking forward to the rata flowering this Christmas,” he says.

Visitors to the Hunua Ranges, Waharau and Whakatiwai regional parks must remain aware they are entering an area recently treated with a toxin for some months to come. Signs will remain in place until early 2016. This caution period is one of the operational requirements of using a toxin like 1080 and is a good reminder to visitors that they may encounter bait that hasn’t yet broken down or pest animal carcasses.

1080 is deadly to dogs, and dog owners should take particular care, both inside and close to the operational area, to make sure dogs are not allowed to scavenge carcasses.


News from the kōkako monitoring team: our contractor has just found the first nest (ever) being sat on by a pair of kōkako outside of the intensively managed area (pairs have been observed outside the managed area previously but no nests ever seen).  A monitoring plan is being put in place for this nest and others and we’ll provide updates on breeding progress in the coming weeks.


Further Information


A note on beech masting (following recent Battle for the Birds results)

We have beech species in the Auckland region but they are not a dominant forest type like they are in the South Island. That said, when beech is masting, so too are other species including those in our northern forests.

Fortunately this year’s successful control programme means pest numbers in the Hunua Ranges have been significantly reduced and we are not in the position we were last year with high and increasing pest densities about to thrive as a result of abundant food supply.


The programme

  • 30 July 2015 | Pre-feed of block one with non-toxic cereal baits
  • 21 August 2015 | 1080 applied to block one and pre-feed of block two
  • 14 September | 1080 applied to block two
  • 21 September | Parkland reopens


Visit for more information on the entire project, including why council carried it out and how.


2015 Hunua Pest Control Programme numbers

An informal snapshot of some of our numbers:

  • Eight: the number of closed and warning signs or barriers ignored by one tramper the day after bait application as he kept on walking into the closed park
  • Five: the number of dogs caught by staff inside the operational area unaccompanied by owners
  • More than 272: the number of water samples tested –  with no 1080 detected
  • More than 1100km: covered by track clearance teams
  • Zero: the number of rats and mice detected following two lots of monitoring in the kōkako management areas
  • One: the first nest with incubating kōkako ever observed outside the intensively managed areas.



Excellent news for the Hunua Ranges and especially the kōkako