Dog Island in Anguilla is declared rat-free

Following an intensive five-month programme to eradicate black rats and two years of careful monitoring, Dog Island in Anguilla has officially been declared rat-free. This is the largest Caribbean island to be successfully cleared of non-native rats to protect the island’s threatened wildlife, which is now showing promising signs of recovery.

Covering 207 hectares, Dog Island is an internationally-recognised Important Bird Area, with over 100,000 pairs of nesting seabirds. It also supports lizards found nowhere else on earth and endangered sea turtles, which nest on the island’s white sandy beaches. Until recently, the island was also infested with thousands of invasive black rats, which caused severe damage by suppressing native plants and preying on eggs, chicks, and other animals.

Black rat. Credit: Richard Brown/FFI/DIRP.

Black (or ship) rats were accidentally introduced to the Caribbean by early European explorers and have wreaked havoc on sensitive island ecosystems. Credit: Richard Brown/FFI/DIRP.

The rats were eradicated to allow the recovery of Dog Island’s globally-important wildlife. The eradication took place between November 2011 and March 2012 and was a collaborative initiative between the Anguilla National Trust, the Government of Anguilla (Department of Environment), Fauna & Flora International, the RSPB, and the island’s owner – the Anguilla Development Company.

Devon Carter from the Anguilla National Trust puts out rat bait. Credit: Jenny Daltry/FFI/DIRP.

Devon Carter from the Anguilla National Trust puts out rat bait. Credit: Jenny Daltry/FFI/DIRP.

To target every rat on Dog Island, over 42 kilometres of trails were cut through dense thorn scrub and over two tonnes of rodenticide were applied by hand. More than 30 staff and volunteers worked under the technical direction of Elizabeth Bell, a rat-eradication expert from the New Zealand-based Wildlife Management International Ltd. Difficulties faced by the rat eradicators included high temperatures and large groves of toxic manchineel trees.

Rat eradication team wearing suits to protect them from poisonous manchineel trees. Credit: Richard Brown/FFI/DIRP.

The team showed good humour, despite having to wear sweltering protective suits in the Caribbean sun. Credit: Richard Brown/FFI/DIRP.

“The volunteer team and I spent 11 weeks camping on Dog Island to complete the black rat eradication, working long hours in hot and difficult conditions. As I am sure all of the volunteers will agree, one of the worst parts of the project was having to cut tracks through nearly 30 hectares of manchineel,” said Elizabeth (Biz) Bell, Senior Ecologist at Wildlife Management International Ltd.

“Despite this, it was fantastic to live and work amongst the native species such as ground and tree lizards, frigatebirds, boobies and tropicbirds that the project was working to protect. It was a real pleasure to return to the island this February to confirm that the project was a success and see species beginning to recover already.”

Magnificent frigatebirds. Credit: Jenny Daltry/FFI/DIRP.

Magnificent frigatebirds are among many bird species to benefit from the eradication work. Credit: Jenny Daltry/FFI/DIRP.

The last rat was removed on 18 March 2012. However it is international practice only to declare an island rat-free after two years have elapsed since the last rat was detected. No native wildlife were harmed during the eradication operation on Dog Island and any bait remaining quickly breaks down into harmless components.

Hon. Minister of Environment, Government of Anguilla, Mr Jerome Roberts, recognises this partnership and national accomplishment. Minister Roberts stated, “This milestone of an achievement is a testament to the calibre and commitment of the persons who work on behalf of Anguilla and is a reflection of Anguillian tenacity for success. This achievement is only the beginning, now our innovation must create sustainable opportunities for the future.”

Supported by the National Fish and Wildlife Foundation, the Anguilla Governor’s Discretionary Fund and Syngenta, this is the largest and most difficult rodent-eradication project to have been successfully completed in the Caribbean.

Anguilla Bank tree lizard. Credit: Jenny Daltry/FFI/DIRP.

Reptiles such as this Anguilla Bank tree lizard are also beginning to recover. Credit: Jenny Daltry/FFI/DIRP.

“Tackling invasive species is vitally important for conserving native Caribbean wildlife, protecting human health and even building resilience to climate change,” said Dr Jenny Daltry, Senior Conservation Biologist with Fauna & Flora International. “Removing the rats from the wonderful Dog Island has been well worth all the effort – amazingly, some of the native species have already doubled in number.”

In addition to helping native wildlife, this project has also built Anguilla’s capability to plan, implement, and monitor invasive species-eradication projects. Given the level of national and international interest to undertake similar initiatives on other offshore islands and cays, the development of national capacity is particularly important.

“This is an extremely significant accomplishment for Anguilla and indeed the rest of the region in our ongoing efforts to safeguard and restore our territories’ biodiversity,” said Avon Carty, President of the Anguilla National Trust. “I am very proud of the work done by the team at the Anguilla National Trust and I’m grateful to all our partners for their support, assistance and expertise in helping us bring this project to a successful conclusion.”

For more information about the Dog Island Restoration Project (DIRP) and those involved, read the press release (PDF).