30 Jun 2014

Dog Island, Anguilla, declared rat-free

The newly hatched chick of this Brown Booby can grow without fear of invasive rat predation. Photo: Richard Brown, FFI-DIRP
By Shaun Hurrell

Following an intensive five-month programme to eradicate black rats and two years of careful monitoring, Dog Island in Anguilla – a UK Overseas Territory in the Caribbean – has been officially 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 already showing promising signs of recovery.

Covering 207 hectares, Dog Island is an internationally-recognised Important Bird and Biodiversity Area (IBA), 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, non-native black rats Rattus rattus, which caused severe damage by suppressing native flora and preying on eggs, chicks, and other animals.

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 among the Anguilla National Trust, the Government of Anguilla (Department of Environment), Fauna & Flora International, the RSPB (BirdLife in the UK), and the Anguilla Development Company which owns the island.

Devon Carter (Anguilla National Trust) putting out rat bait</br>Photo: 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 Hippomane mancinella.

The last rat was removed on 18th 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.

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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.

In addition to helping native wildlife, this project has also built Anguilla’s capability to plan, implement, and monitor invasive, non-native 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 relevant.

“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 to bring this project to a successful conclusion."