During this year's Invasive Species Week (15-21 May 2023), Professor Helen Roy writes from Anguilla to explain how the problem of invasive non-native species affects the UK Overseas Territories in particular and the collaborative steps being taken to enhance information around the issue...

The diversity of plants and animals on the UK Overseas Territories is incredible. Most of the UK Overseas Territories are islands and all have unique ecosystems that provide a home for many species including those not found anywhere else in the world - endemic species. Islands are particularly vulnerable to biological invasions. Invasive alien species are implicated as the main cause of extinctions on islands and have also contributed to declines of many more species.

A few years ago, the UK Centre for Ecology & Hydrology (UKCEH) worked in partnership with many people to derive lists of invasive alien species that are currently absent but pose a high risk of arriving on the UK Overseas Territories. It was a privilege to work with people on the UK Overseas Territories – their knowledge was critical to the process of horizon scanning which involved rapidly assessing the potential impacts of thousands of species.

The study made evident the need for a system to collate information on non-native species across the UK Overseas Territories and to consider priorities for monitoring to increase the information available for decision-making. In 2022 we began a Darwin Plus-funded project to work collaboratively with experts on the UK Overseas Territories to work towards the aim of enhancing the availability of information on invasive non-native species.

Adult Booby and chick on Dog Island, Anguilla

Anguilla is home to globally important bird colonies. Boobies are among the species thriving on Dog Island, Anguilla after the successful eradication of invasive rats in 2012.

Lignum vitae, an endangered plant on Prickly Pear island, Anguilla

Lignum vitae is an endangered plant now thriving on Prickly Pear East island, Anguilla

Over the last year, we have begun to compile information on non-native species for each of the UK Overseas Territories. In coming years, we will work with partners on the UK Overseas Territories to review this information while also prioritising the monitoring and reporting of invasive non-native species. It is very exciting to be in Anguilla for Invasive Species Week and to hear about ongoing, inspiring initiatives on invasive non-native species and begin to discuss future opportunities for monitoring.

The Anguilla National Trust took us to two outer islands – Dog Island and Prickly Pear East – to highlight the incredible conservation work they have undertaken, in partnership with others, particularly rat and mouse eradications to safeguard many important species, including globally important seabird colonies.

The sooty terns, boobies and frigatebirds are thriving on Dog Island following the successful eradication of rats in 2012. We were fascinated and inspired to hear about the immense conservation work that is ongoing on this island. It was also wonderful to see the small stone igloos that had been built for nesting red-billed tropicbirds after Hurricane Irma had destroyed many of the structures they had been using. We were utterly delighted to see a not so tiny tropicbird chick occupying one of the igloos.

Prickly Pear East is now home to the Lesser Antillean Iguana that was threatened by the introduced invasive alien green iguana on the main island of Anguilla. To see this amazing animal thriving on Prickly Pear was incredibly exciting.

These initiatives demonstrate the incredible commitment of people on the UK Overseas Territories, from the government departments to the NGOs, to safeguarding these unique biodiversity and ecosystems.

Staff from Anguilla National Trust, UKCEH and the Joint Services Health Unit gathered for a workshop to explore action on non-native species
Participants at the workshop on enhancing monitoring and prevention of invasive non-native species on Anguilla

We hope that the information systems we develop with our inspiring partners on the UK Overseas Territories will play a part in addressing the threat of biological invasions to islands. We are extremely appreciative of all the time and expertise that has been given so far and we are looking forward to our ongoing collaborations. Particular thanks to Carencia Rouse, Director of Environment - Department of Natural Resources and Rhon Connor, Environment Officer - Department of Natural Resources, for their support and guidance including co-developing the workshop programme. 

Helen Roy