The mammals are not native to the isles and have been blamed for preying on the eggs of ground-nesting wading birds.

BBC: Hedgehogs may have returned to cleared areas of Hebrides

"We hope the clearing of a lot of bracken and re-seeding of heather will bring back ground-nesting birds as well as more cuckoos, " she added.

BBC: Birdwatcher gave 1922 cuckoo clue

Now their appetite for the eggs and chicks of ground-nesting birds such as the South Georgia pipit and pintail is threatening the survival of these endemic species.

BBC: South Georgia rat cull begins again

Nick Hazlitt, a forester with the Forestry Commission, said they were also hoping to promote wildlife on the site, which is important for ground-nesting birds, dragonflies and damselflies.

BBC: Burnt forest rises from the ashes

For ground-nesting birds like the South Georgia pipit and South Georgia pintail, both of which are unique to the island, the rat explosion spells disaster because the rats feed on chicks and eggs.

BBC: Rat eradication project on South Georgia set to resume

This place, a nesting ground for the Atlantic puffin, is also at the centre of a long-rumbling border dispute between America and Canada.

ECONOMIST: An international grey area