Plague of rats a threat to islands' heritage status

Britain has been warned by the United Nations that it is at risk of losing two of its five listings for natural World Heritage sites unless it urgently provides funding to eradicate rodents which are threatening critically-endangered bird species found only on two remote islands.

Rats and mice introduced by humans on to the British-administered Henderson Island – part of the Pitcairn Islands in the South Pacific – and Gough Island in the South Atlantic are destroying unique bird populations, including breeds of petrel and albatross, by eating vast numbers of eggs laid by the seabirds which have no natural defence against rodents.

Unesco, the UN heritage body, this week warned the Government that the status of the islands as natural World Heritage sites – alongside such locations as the Great Barrier Reef and the Galapagos Islands – is in danger of being removed unless work is done to stop the birds being driven to extinction.

The Royal Society for the Protection of Birds (RSPB) described the intervention as "extremely embarrassing" for the Government and called for £700,000 to be provided towards the £1.7m cost of clearing Henderson Island of its 30,000-strong population of the Pacific rat introduced by Polynesian natives in the 14th century.

The sub-tropical island, along with Gough Island, is one of 14 British Overseas Territories and therefore the direct responsibility of London. It is home to five species found nowhere else on earth, including the Henderson petrel which once numbered five million pairs but now stands at just 40,000 pairs. The two islands are uninhabited and among the most inaccessible places in the world.

Ornithologists warn that the petrel could be extinct within a few years unless urgent action is taken to kill the rats, which eat 25,000 chicks a year - equivalent to 95 per cent of the eggs laid by the birds. The Tristan albatross, which is one of three species unique to Gough Island, is suffering a similar rate of decline due to super-sized domestic mice which have grown fat on the easy prey of newly-hatched chicks.

At a meeting in Brazil this week, UNESCO called on the Government to rapidly find the money to pay for rat eradication on Henderson Island, warning that it was of "critical importance to maintaining... the integrity of the property". Last year it adopted a similar position on Gough Island and set a 2014 deadline to exterminate the mice.

Grahame Madge, spokesman for the RSPB, said: "Unless action is taken to halt the decline of the species, then the inevitable result will be their extinction. Because of the remoteness of these islands, they are like evolutionary time capsules and these bird species have developed untouched by the outside world.

"For the British Government to be told that it is currently failing the designation of these islands as World Heritage sites is extremely embarrassing."

A Government spokesperson said, "We place great importance on conserving the biodiversity of the UK Overseas Territories. We have provided £213,000 to protect biodiversity on Henderson Island, and almost £350,000 for Gough Island, and welcome applications for further funding."