FIFTY-SEVEN gecko eggs bred at Jersey Zoo have been returned to Mauritius five years after a 1,000-tonne oil spill pushed the already threatened species closer to extinction.
The lesser night gecko eggs were taken to the Mauritian islet of Ilot Vacoas in January, and 88% of them have now successfully hatched.
The eggs were produced by geckos at Jersey Zoo that had been rescued by Durrell in 2020 when the MV Wakashio tanker ran aground on a coral reef off the coast of Mauritius.
Around 1,000 tonnes of toxic oil spilled into the ecosystem as a result, which caused irreversible damage to local wildlife.
The lesser night gecko is found only on four islets and is now listed as “vulnerable” on the International Union for Conservation of Nature’s Red List of Threatened Species.
DNA analysis of wild geckos on Ilot Vacoas, carried out by Cardiff University using samples from 2021 and 2022, showed that the oil spill had altered the genetic structure of the population.
This reduced the geckos’ ability to adapt to future threats and increased the risk of extinction, but the geckos in Jersey Zoo retained pre-spill genetic diversity.
From mid-2023, Durrell’s Herpetology team adjusted lighting and enclosure conditions at Jersey Zoo to replicate the Mauritian climate and encourage breeding at the right time of year.
In January 2025, 57 eggs were returned to Ilot Vacoas in partnership with the Mauritian Wildlife Foundation and the National Parks and Conservation Service.
Custom-built egg release units were used to protect them from predators and weather.
Durrell now has plans to replicate this translocation on an annual basis at a larger scale, to further safeguard the future of this species.
Island restoration manager Dr Nik Cole helped co-ordinate the rescue effort and was part of the team who undertook the translocation.
“This whole project from start to finish has provided a much-needed lifeline for this precious species,” he said.
“Transporting these eggs halfway across the world and having such a high hatching rate is no mean feat.
“For our first repatriation effort, we couldn’t have asked for better results, it’s truly phenomenal.”
Durrell CEO Becky Brewer added: “The successful return of these gecko eggs to the wild is a hopeful moment in a story that could have ended very differently.
“It shows what’s possible when science, commitment and collaboration come together to protect life on the edge.”
