Campbell Island rat eradication

While it is not known when rats arrived on Campbell Island, they were well established when the first scientific expedition visited the island in 1840. By this time they had eliminated all the native land birds and most of the smaller seabirds from the main island.

Helicopter bucket being loaded with Pestoff 20R poison bait at dawn? part of the Rat Eradication Programme, Campbell Island. Photo: P.Tyree.
Helicopter bucket being loaded with
Pestoff 20R poison bait. Part of the rat
eradication programme, Campbell Island

Rats, along with cats, which had presumably been introduced to help control the rats, continued to wreak havoc on the island's wildlife. Populations of the few seabird species that managed to hang on were continually being reduced and any land birds which dared to try and re-establish were killed.

The idea of removing rats from an island the size of Campbell was considered by most to be just a dream, but that changed in 2001 when, after more than 20 years of preparation, research and technological advancement, a DOC team headed to the island to take on the rat!

There are no half measures with eradication, you either succeed or you fail, and to succeed you must kill every last individual, one pregnant female is all it takes to re-establish a population and all the time and effort is wasted.

Removing the Norway rat from Campbell Island was always going to be a massive operation. Not only did the team have to contend with the logistics of it, being 700km south of Bluff, but they also had to contend with the harsh weather.

The issues

Some of the issues that had to be worked through before the project could proceed included:

Making the project financially and logistically feasible

Aerial view of the Meteorological Station, used as the base for the Rat Eradication Programme, Tucker Cove, Campbell Island.
Aerial view of the Meteorological Station, used as the base for the Rat Eradication Programme at Tucker Cove on Campbell Island

This meant modifying the standard eradication methodology, which had been developed over the previous 20 years, so that the bait could be transported, stored on the island and spread within the available time frame the bait rate needed to be reduced.

In order to test the reduced rate, a field trial was carried out on the island in 1999 when non toxic bait was spread over 600ha and the rats in that area trapped. This showed that all rats would have access to the bait at the new rate.

Non targets

While there were no native land birds present on the island, having been eliminated by the rats, it was recognised that some gulls would probably be killed after eating the bait. However, it was agreed that the benefits of the eradication outweighed this cost.

Bait storage

An entirely new system of bait storage was developed for the project using purpose built ply wood, which could keep the bait dry in the harsh Campbell climate and be flown under a helicopter, as well as being used as a loading platform.

The operation begins

In June 2001 a team of 19 people including pilots, eradication experts and staff who had spent several years working on the island, headed south. They took with them everything they would need for three months on the island, this being the time estimated that it could take to get the weather required to spread the bait.

It ended up being a relatively mild winter, by Campbell Island standards, and the drop was completed in just under one month, with no injuries or major incidents.

In total, 120 tonnes of cereal bait, containing the anticoagulant toxin Brodifacoum, were spread across the island using four helicopters (three spreading bait and one ferrying the bait up to selected loading sites).  

By the time the project was completed it had involved DOC staff and contractors, the Royal New Zealand Navy, the Royal New Zealand Air Force, the Met Service, four helicopter companies, two shipping companies and numerous other people and agencies who provided their time and expertise.

Pete McClelland and team member looking for rats with radio transmitters attached after the poison drop.
Pete McClelland and team member looking for rats with radio transmitters attached after the poison drop

Campbell Island rat free

In 2005, after several checks including using specially trained dogs, Campbell Island was declared rat free.

The announcement coincided with the release of a report led by the Department of the Prime Minister and Cabinet that examines innovative practice in the New Zealand public service. In it, the Campbell Island rat eradication project is cited as an example of good innovative practice. The report examines elements of this project, and others, that has made them so successful.  Using the Campbell Island story, we highlight some of the elements necessary for innovation to occur.

Innovation creates value and improves performance. It does good things for organisations and those who work in them. The Campbell Island rat eradication and the journey leading up to it, mean that DOC is well recognised a leader in island pest eradication and our expertise is sought internationally.

The rat eradication was closely followed by conservationists around the world. Its success meant other eradication possibilities, previously been considered impossible, were now feasible. This includes eradications in the Falklands, the Aleutians off Alaska, the Galapagos Islands, Macquarie Island south of Campbell Island (completed in 2010) and even the 3756 sq km South Georgia Island in the South Atlantic.

Today DOC is regarded as a world leader in the area of pest removal and is routinely called upon by other countries to offer advice and assistance on eradication programmes.

As Sir David Bellamy put it: “New Zealand is the only country which has turned pest eradication into an export industry.”

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Contacts

Murihiku / Invercargill Office
Phone:      +64 3 211 2400
Email:   invercargill@doc.govt.nz
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