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Pēhea ai mātou e tiaki i te pae maunga o Hunua i ngā kīrearea

How we protect the Hunua Ranges from pests

Possums and rats threaten native animal and plant species in the Hunua Ranges.

2022 pest control operation

Between August and November 2022, 1080 bait was aerially applied to the Hunua Ranges.

The operational area included:

  • parkland
  • Department of Conservation (DoC) land
  • neighbouring private land.

What happened

We used a two-step application method to make sure the operation was as successful as possible.

  • Step one: A non-toxic pre-feed familiarised pest animals with the cereal baits that made them hungry for more.
  • Step two: Bait containing the 1080 (sodium fluoroacetate) toxin was applied.

To manage the large area and protect water supply reservoirs, the operational area was divided into two blocks. The catchments were:

  • Cossey and Mangatangi
  • Wairoa and Mangatawhiri.

Get a copy of the 2022 operation area map

Reservoirs in each block were switched off during the operation. Water supply was released after rigorous testing confirmed no 1080 was detected in the water.

Each hectare received around two kilograms of cereal pellets.

The 1080 was applied to the land using a helicopter guided by a global positioning system (GPS).

Unauthorised removal of signs or baits is a criminal offence.

We followed strict guidelines set down by the Government’s Environmental Protection Agency (EPA) and the Ministry of Health (MoH). 

Park Access

Access roads and tracks within the parks and reserves were closed while the operation was in progress. Warning signs were placed outside affected areas.

The parks reopened after a comprehensive track clearance programme was completed. The public was notified when the park reopened.

Get a copy of Hunua Ranges: Pest Management and use of 1080

​Information regarding neighbouring properties

We contacted neighbours and landowners with land next to the area approximately 24 hours before the operation started.

Email if you would like to receive regular landowner updates.

It is important you tell us if your land has a private water take used for human consumption within 400 metres of the parkland. Email with your contact details.

Safety tips 

During the operation and the caution period:   

  • Do not touch bait, which is dyed green.
  • Watch children at all times.
  • Do not eat animals from this area.
  • Keep dogs away from poison baits and carcasses, as 1080 pellets are toxic to animals.
  • Please read and follow all park safety signage.

Poison centre details

If you suspect poisoning, call the New Zealand National Poisons Centre immediately.

0800 764 766

Keeping dogs safe

Dogs are the most at-risk pets during a 1080-based pest control operation. Always supervise your dog in affected areas. Do not allow them to roam or scavenge carcasses and consider using a muzzle.

If you suspect your dog has ingested 1080 poison, make the dog vomit immediately if possible and call your vet straight away.

For more information, see our dog protection fact sheet.

Safeguarding water supply

This operation was in water catchment areas, so it required careful planning and working closely with Watercare.

Measures were put in place to ensure the ongoing safety of Auckland's water supply, including:

  • no flying over water supply reservoirs
  • exclusion zones around reservoirs where no bait was applied
  • using accurate (GPS) technology to apply bait
  • suspending reservoirs before the operation and only returning them to service after rigorous water testing confirms there was no 1080 detected in the water
  • working with landowners to understand what streams they use for drinking water that flow out of the operational area.

2018 pest control operation

Between September and October 2018 we aerially applied 1080 (sodium fluoroacetate) to around 21,500ha of parkland, adjoining Department of Conservation (DoC) administered land and some private land in the Hunua Ranges area. This followed the first such operation in 2015.

A caution period was in place for six months following the operation to prevent a risk to people or pets from any remaining bait or pest animals that died from consuming the bait.

We carried out a full water testing programme following the operation. 1080 was not detected in any of the more than 100 samples.

Results of aerial application of 1080

Following the 2018 operation, the number of pest animals in the ranges was at an all-time low, with rat and possum densities significantly reduced across the area.

When planning for the operation, estimations of rat coverage across the ranges was at 75 per cent and possum numbers had begun to increase again following the 2015 operation.

Post-operational monitoring has indicated the application was very successful. Pest species dropped dramatically, with estimated possum coverage across the ranges at 0.23 per cent and zero per cent for rats.

Species monitoring is also a strong indicator of success. Following the 2018 operation, the highest number of mature chicks since the Kokako Protection Project began was recorded from monitored pairs.

Important visitor information

Observe all information and warning signs.

Ground-based pest control will be in place on areas of parkland and some surrounding private land that wasn't treated during the aerial operation.

Always keep your dogs on a leash. This is a requirement within the park at all times.

A Controlled Area Notice is in place across the native forest area of the Hunua Ranges Regional Park and adjoining DoC-administered lands. This is to protect against kauri dieback disease.

Use hygiene stations to clean and disinfect all footwear and equipment to ensure you do not carry any visible soil into the controlled area.

More information

In 2011 the Parliamentary Commissioner for the Environment released an independent report endorsing 1080 use.

Download the report from the Parliamentary Commissioner for the Environment website.

DoC also looks after large areas of parkland and uses 1080 application to manage animal pests.

For more information on the use of 1080, see the DoC website.

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