Palmerston Island is one of the most isolated islets that make up the Cook Islands. Photo: Finlay Cox
A remote coral atoll about 400km away from the Cook Islands capital Rarotonga, with a population of under 50 people, is on a mission to eradicate rats on the island by the end of this year.
Palmerston Island is one of the most isolated of the 15 islands that make up Cook Islands, better known for its picture-perfect white sandy beaches and pristine natural environment.
But the island's residents are having to put up with tiny rodents that they say have become a "nuisance".
"Rats are a problem on Home Island (the islet that is occupied by people)," Palmerston's executive officer Arthur Neale said.
"They have been a nuisance. They damage our crops, coconuts, fruit trees. So you're always battling the rats."
In 2018, the Palmerston Island council commissioned a natural resources study that showed there was very little birdlife where rats were present.
Neale said rats have become a "menace" and threaten the "community and the ecosystem".
He said that is why the Palmerston Island community has sought assistance from New Zealand's Department of Conservation and other local organisations, who have now band together to rollout a full scale rat eradication project expected to kick off by June.
'We are hopeful'
The conservation department's Em Oyston travelled to Palmerston for a three-week feasibility study last November.
The research included identifying the distribution of rats and determining how much bait was needed to eradicate them.
While Oyston is optimistic all rats would be gone from the atoll by the end of the year, he acknowledged that it would not be an easy exercise.
"In the tropics it is particularly hard to eradicate rats just because it is such a productive environment," he said.
"There has been cases where operations which have done everything right have still failed. But we are quite hopeful that all the issues we have identified will be managed well."
Neale agrees that it would be a "big undertaking" to ensure they were able to eliminate all rats.
Clutter needs to cleared and the only food accessible to the pests has to be rat bait, he said.
"It was also open season on the chickens that freely roam the island, to ensure they do not consume the bait meant for the rats."
He said that would be the challenge for his team to adequately prepare and do their part for the project to be successful.
Rats are a threat to the Palmerston Island community. Photo: 123RF
Rats impact livelihoods
Local NGO Te Ipukarea Society's technical director Kelvin Passfield, who is helping with the initiative, said rats interfered with sea bird populations, particularly birds that nest on the ground.
"The chances are that there would be a lot more seabirds nesting on the motus if they didn't have rats," Passfield said.
"Palmerston islanders are actually reliant on seabirds as a source of food from time to time so it will increase there food supply if the rats weren't impacting the populations."
Passfield said the guano or seabird droppings helped fertilise the reef, that would make it more resilient to the impacts of climate change.
Te Ipukarea Society has been trying to completely eliminate rats on the uninhabited island of Suwarrow since 2018, with their last visit in May 2022.
Passfield said he is fairly confident they are all gone now and hopes rat eradication would continue to the other islands that make up the country.
However, he added Suwarrow and Palmerston were "low hanging fruit".
"Some of the other islands are going to be much more difficult," he said.
"The southern group of islands, for example, are much bigger. They are not atolls, they are rugged makatea islands or high islands [with a] much more rugged interior.
"They are much more difficult to go in so it is a much bigger job to get rid of rats from other islands."
But this was why the Palmerston project could be an exciting stepping stone, Oyston said.
"If this is successful it really does potentially open up the door for scoping some of the islands larger populations," he said.
"So it is a real litmus test in terms of the social side of things and a formula for how it could work."
A red tailed tropic bird and chick: these ground nesting birds nests and chicks are vulnerable to rat predation, and cannot be found nesting on the islets where rats are present on the atoll. Photo: Em Oyston
