Biodiversity of the UK Overseas Territories

The UK’s 16 Overseas Territories (UKOTs) support more biodiversity than the whole of the UK mainland. At least 180 endemic plant species (species which are restricted to a particular region) are already known from the UKOTs, compared to around a dozen on the UK mainland. As some parts of the Territories have never been explored botanically, there are undoubtedly many plant species as yet unknown.

Eight of the 16 UKOTs are situated within regions described as ‘biodiversity hotspots’ which are of high conservation priority – the Caribbean, Mediterranean and Polynesia/Micronesia in the Pacific.

Most of the UKOTs are remote islands; many of their plants and animals have evolved in isolation. They have a high proportion of species that are unique (endemic) to their home islands.

The UKOTs encompass many diverse habitats ranging from the icefields of the British Antarctic Territory to the coral reefs and tropical forests of the British Indian Ocean Territory and the British Virgin and Cayman Islands.

The UK and Territory Governments bear joint responsibility for conserving and protecting the rich natural heritage of the UKOTs and are working together to meet obligations under international environmental conventions.

Fascinating facts

St Helena (122 sq km) has 49 endemic plant species and 10 endemic genera, most of which comprise just one species (monospecific).

Two islands within the UKOTs are listed as World Heritage Sites on account of their biodiversity: Henderson Island (within the Pitcairn group) and Gough and Inaccessible Islands (part of the Tristan da Cunha group) are home to important undisturbed seabird breeding colonies.

As well as 180 endemic plant species, there are 54 endemic birds, 39 endemic amphibians and reptiles, and 685 terrestrial invertebrates already identified within the UKOTs.

Although only two flowering plants grow in the British Antarctic Territory, there are more than 100 mosses and 300-400 different lichens.

Abutilon pitcairnense from Pitcairn Island was believed to be extinct until 2003. A single plant was rediscovered and propagated, just before its site was destroyed by a landslide.

Ascension Island has just 25 native higher plant species. Six of these are unique ferns, all of which are considered to be rare or endangered.

Latest UKOTs plant biodiversity news

On a recent field trip to the British Virgin Islands, Kew botanists discovered specimens of Acacia anegadensis growing on the uninhabited island of Fallen Jerusalem. Previously, this species had only been known from Anegada. This exciting new find, on a completely different island, means that the species has an increased chance of survival in the wild.

Another rediscovery took place in the Cayman Islands in 2007, when the Cayman sage (Salvia caymanensis) was spotted growing near a road on Grand Cayman. Local conservationists had believed that this species had become extinct. Seeds of the Cayman sage have been collected for storage in the Millennium Seed Bank.

Find out more about biodiversity in the UKOTs:

Joint Nature Conservation Committee - Biodiversity: the UK Overseas Territories
UK Overseas Territories Conservation Forum