By Shreya Dasgupta for Mongabay, part of the Guardian Environment Network From The Guardian UK

Mongabay: Redonda’s invasive black rats and long-horned goats have transformed the once-forested island into a ‘moonscape’, conservationists say

The remote Caribbean island of Redonda, part of Antigua and Barbuda, is home to numerous species of plants and animals found nowhere else on earth. It is also home to invasive black rats and non-native goats that are wiping out the island’s native, rare wildlife, conservationists say.

To help the island’s flora and fauna, the Government of Antigua and Barbuda is now initiating a plan to remove all goats and rats from the island. The Redonda Restoration Program program has been formed by the Antigua & Barbuda Government and the Environmental Awareness Group (EAG) in collaboration with organizations like Fauna & Flora International, British Mountaineering Council, Island Conservation and Wildlife Management International Ltd.

“This work will dramatically transform an entire island ecosystem,” Sophia Steele of Fauna & Flora International told Mongabay. “It will save a number of rare endemic species from otherwise almost certain extinction, such as the Critically Endangered Redonda tree lizard, which currently finds itself living on an island almost devoid of trees.”

The island currently has a population of over 5,000 invasive black rats that prey on the island’s native species. The rugged island is also home to around 60 long-horned goats that humans brought to Redonda more than a century ago. The rats and goats are believed to have been introduced into the island by a guano mining community, which was disbanded after World War I.

Both species have drastically transforming the island’s landscape, conservationists say, changing the “once-forested” Redonda island into a “moonscape”.

In fact, the island has such few trees that even the goats are starving. Goat skeletons lie littered across the island, according to the statement. There are very few standing trees left on the island to stabilize the ground, conservationists say, “causing soil and rocks to crumble into the sea, threatening nearshore coral reef in the waters below.”

The Redonda Restoration Program aims to capture and move all long-horned goats to Antigua, where the Department of Agriculture will care for them.

“This will take around two months depending on how cooperative the goats are,” Steele told Mongabay.

Astley Joseph, Deputy Director of the Department of Agriculture, added: “We believe it is important to rescue this rare breed because it could have useful drought-adapted genes that would benefit other herds on Antigua and elsewhere.”

After the goats are relocated, the Program will initiate the eradication of rats using a rodenticide bait, which will take an estimated 8 to 12 weeks. Rodenticide baits have been previously used to eradicate rats on more than 20 other Caribbean islands, conservationists say, without harming native wildlife.

“We aim to complete the rat eradication work by June 2017, but an additional two years of monitoring will then be carried out before we can confidently declare the island to be rat-free,” she added.

Changes to Redonda’s flora and fauna will be visible within the first year, Jenny Daltry of Fauna & Flora International told Mongabay. Removal of rats and goats, for example, will allow plants to grow, she added. Similarly, with rats gone, seabirds, reptiles and other invertebrates can flourish.

“On other islands we have restored, lizard populations have doubled within two years,” Daltry said. “Within five years, the seabird colonies will have almost doubled in size, and additional seabirds and land birds will recolonize Redonda from neighboring islands. After about 15 years, native trees will have matured to re-create woodland in sheltered areas where there are still pockets of soil, land birds and butterflies will be returning, and the island will be alive with wildlife. Birds and bats will continue to assist the reforestation process by bringing nutrients and seeds from neighbouring islands. By this stage we can also consider reintroducing species that could not easily colonise the island unaided, such as iguanas, burrowing owls and certain tree species.”

However, the island is remote, rocky and hazardous, with seriously unstable slopes and tall cliffs, Daltry said. And this makes restoration work risky. Moreover, the program is in urgent need of funding to complete this work, she added.

IMAGES:

Redonda from the air. The island, once forested, now looks like a lunar landscape. Photograph: John Cancalosi/Alamy Stock Photo

Redonda ground dragon ( Ameiva atrata), an endemic species that is found only on Redonda Island. Photograph: Jenny Daltry/Fauna & Flora International

So few plants survive that even the goats are beginning to starve to death. Photograph: Jenny Daltry/Fauna & Flora International

Rat eradication work is due to be completed by June 2017, with an additional two years of monitoring. Photograph: John Cancalosi/Alamy