Removal of invasive alien species from offshore islands in Puerto Rico, Dominican Republic leads to a rebound in endemic species populations
- By : Thérèse Yarde
- Category : Biodiversity
- Tags: dominican republic, puerto rico

Island Conservation, an international organization dedicated to preventing species extinctions by removing invasive species from islands, reports that two of its biggest successes of 2017 were in the Caribbean:
Desecheo Island, Puerto Rico
After more than a decade of conservation intervention, Desecheo National Wildlife Refuge (NWR) is once again safe for the Threatened Higo Chumbo cactus, native seabirds, and unique lizards found nowhere else in the world. Over 100 years ago, the island was a thriving nesting ground for thousands of native seabirds. Approximately 15,000 Brown Boobies, 2,000 Red-footed Boobies (Sula sula), 2,000 Brown Noddies (Anous stolidus), 1,500 Bridled Terns (Onychoprion anaethetus), and hundreds of Magnificent Frigatebirds (Fregata magnificens), Laughing Gulls (Larus atricilla), and Sooty Terns (Onychoprion fuscatus) nested here.
After the introduction of invasive mammals such as goats and rats, the islands seabird population and native vegetation began to dwindle until almost no seabirds were nesting in the refuge. Now … seabirds are returning and the Threatened Higo Chumbo cactus is beginning to show new growth.
Cabritos Island, Dominican Republic
Cabritos is an island within a saltwater lake that is home to two species of threatened iguanas: the Critically Endangered Ricord’s Iguana and the Vulnerable Rhinoceros Iguana. Although the individuals are impressive in size, their populations began to dwindle as invasive feral cats and donkeys destroyed nests, preyed on juveniles, and damaged their critical habitat. The Ricord’s Iguana and Rhinoceros Iguana are the only two rock iguanas that overlap in their natural range. Both species have been declining in the Caribbean due to invasive species and habitat loss.
After years of conservation efforts, these two species now have safe habitat on Cabritos Island. This island ecosystem is now the only place on Earth where the Critically Endangered Ricord’s Iguana can roam free from the threat of feral cats, donkeys, and cows.
Read more about the work of Island Conservation.
The Secretariat of the Convention on Biological Diversity provides concise explanations of what invasive alien species are and why island ecosystems are particularly vulnerable to species invasions.