- Introduced house mice on the UK Overseas Territory of Gough Island in the South Atlantic are killing seabirds at greater levels than feared resulting in at least two million fewer seabird chicks each year
- Without action, the Tristan albatross is likely to be one of the next UK birds to go globally extinct
- Plans are underway to save this and other species. The RSPB confirms plan to eradicate the mice in 2020, in one of the most ambitious projects of its kind ever attempted.
New research shows that mice are eating seabird chicks at an alarming rate, resulting in two million fewer seabird eggs and chicks on a single UK island each year and putting some seabird species at the risk of extinction.
The study, supported by the RSPB, found that the number of chicks and eggs surviving on Gough is much lower than it would be if mice were absent. This environmental catastrophe threatens albatrosses and petrels with extinction.
Mice were accidentally introduced by sailors to the remote Gough Island during the 19th century. Now, over 100 years later mice have colonised the entire island, and evolved to be 50% larger than the average house mouse. They have learned to eat the eggs and chicks of the island’s once abundant birds.
The island, a World Heritage Site in the South Atlantic is considered one of the most important seabird colonies in the world, hosting more than ten million birds. There are 24 species of bird that nest on the island, 22 of which are seabirds.
Gough Island hosts 99 per cent of the world’s Critically Endangered Tristan albatross and Atlantic petrel populations – two species especially vulnerable to mouse predation because their chicks are left alone in winter. Just 2,000 Tristan albatross pairs now remain.
Author Dr Alex Bond said, “We knew there were large numbers of chicks and eggs being eaten each year but the actual number being taken by the mice is just staggering. The seabirds of Gough Island desperately need our help.”
Video cameras placed alongside nests have revealed what happens at the nests. The mice, in groups of up to nine, eat the chicks alive. Albatrosses mate for life, producing just one egg every other year, and parents have been observed returning from a fishing trip to find their chick dead in the nest.
John Kelly, RSPB manager for the Gough Island mouse eradication, said “The RSPB and Tristan da Cunha Island Council have developed an ambitious plan to save the seabirds of Gough Island. The results of this study are a powerful reminder of why we’ve taken this challenge on, to restore the island to its former glory and prevent the future deaths of millions of seabirds.”
The RSPB and Tristan da Cunha government, together with international partners including Island Conservation from the USA and the Department of Environmental Affairs in South Africa, have developed The Gough Island Restoration Programme. Not letting the challenges of working on one of the world’s most remote islands get in the way, the Gough team are planning to eradicate mice from Gough Island in 2020 to stop this from happening once and for all.
Anthony Caravaggi, lead author and researcher at University College Cork and Queen’s University Belfast said, “We usually think of rats as problem rodents on islands but this shows that house mice can have catastrophic impacts all on their own. If we don’t remove the mice from the island then we’re going to lose several unique species and an important island for breeding seabirds.”
Defra Minister for non-native species, Lord Gardiner said, “This study highlights the need for urgent action if we are to save the iconic seabirds of Gough Island. That is why we support RSPB in this project and why we are taking action to tackle the threat posed by non-native invasive species in our overseas territories.”
Ian Lavarello, Chief Islander, Tristan da Cunha said, “We have a unique opportunity to save Gough Island and the species that make their home there. If we do nothing, we will eventually lose this amazing South Atlantic seabird mega-colony and its contribution to the world’s oceans will cease. With dedication and rigorous planning, success is possible. Monumental programmes such as this are not without their challenges but the rewards for global conservation are great.”
For more information visit www.goughisland.com