Small islands like Little Cayman and Cayman Brac are on the front lines of global biodiversity loss. Having evolved for thousands of years in relative isolation from humans, our islands nurtured unique species, many of which are found nowhere else in the world.
For decades, scientists have been studying the delicate ecosystems of islands, recognizing and documenting their particular vulnerability – and how determined, science‑driven action can reverse even severe ecological decline.
For 25 years, the Island Invasives conference has been the forum for experts in invasive species management from around the world to share knowledge and experiences. This year, Simone Williams, a Terrestrial Researcher with the Department of Environment and Tamara Doyle, Little Cayman resident and Sister Islands Biosecurity Officer with the National Trust, traveled to Auckland, New Zealand to present how the two organizations are working together to safeguard the delicate ecosystems of Little Cayman. Simone expressed pride in representing the work of the DoE.
“It was truly an honour to represent Cayman in New Zealand. We summarized years of fieldwork and community engagement in our presentation, showing how invasive species such as feral cats, rats and green iguanas have impacted Little Cayman’s ecosystems and how coordinated management between the Department of Environment, Department of Agriculture, and the National Trust with UK Darwin+ funding and project support from the RSPB has begun to restore them. We are especially proud that the data we presented is currently being peer reviewed by IUCN (International Union for Conservation of Nature) with publication expected later this year.”
The vulnerability of island ecosystems
Simone and Tamara presented research conducted by the Department of Environment to an audience of over 350 scientists and invasive species management teams from island communities around the globe. Tamara described the experience as powerful.
“Many in the audience didn’t know where the Cayman Islands are. So, we first introduced Little Cayman as a “fragile paradise” that is home to many rare and unique species, including the critically endangered Sister Islands Rock Iguana (SIRI) which is found only in our Sister Islands and nowhere else in the world,” said Tamara. “It’s estimated that while islands comprise only 6.7% of the world’s total land mass, they are home to around 20% of Earth’s biodiversity. So, sharing our story with people managing similar circumstances was really powerful.”
“In 2019, Little Cayman’s rock iguana surveys showed very few hatchlings, and aging breeders, a clear sign of a population at risk of extinction,” explained Simone. “Trail cams placed in the interior forests of all three islands revealed high densities of free roaming cats living in the wild which prey on our native reptiles and birds, even deep in the interior forests, far away from human habitation.”
These threats extended beyond Little Cayman’s iconic giant reptiles. In Cayman Brac, the island’s brown booby colony, once thousands strong, is now on the brink of local extinction.
To prevent the global extinction of SIRI and local extinction of the Brown Booby, as well as relieve pressures on other native species, efforts began to remove black rats, and feral cats, from Little Cayman and brown booby nesting areas in Cayman Brac.
“Before the work began in 2022, rock iguana numbers in Little Cayman had plummeted to around 1,000 individuals left,” confirmed Simone. “But once unowned feral cats were removed, the population rebounded dramatically, tripling to more than 3,500 by 2025 driven by a more than 10-fold increase in the number of hatchlings and 1-year old iguanas observed during the survey.”
A turning point through community‑led conservation
“Understandably, early efforts faced some public skepticism,” Tamara recalls. “But, through research, transparent communication, community meetings, and stakeholder engagement, people came to understand the true scale and nature of the problem.”
By 2024, the vast majority of Little Cayman’s residents supported reducing feral cat impacts on native wildlife by removing unowned animals from the wild and promoting indoor pets as best practice. In 2025, 100% of pet cats on the island were voluntarily registered, microchipped, and sterilized, as part of the programme, ensuring that conservation efforts continue to target feral, unowned animals living in the wild, and not pets.
“I want to especially thank the members of the Little Cayman community who fully sponsored my trip because they recognize the importance of this work in protecting Little Cayman’s unique environment,” said Tamara. “We have so many beautiful animals found only in the Cayman Islands or on the Sister Islands and nowhere else in the world. That’s such a special thing,” she said. We have a responsibility as a community and a nation to ensure they don’t become extinct on our watch.”
