Scientists have welcomed the first results of a captive breeding program aimed at saving a group of critically endangered Fijian crested iguanas, the first such attempt to reintroduce a species in that country.
Some of the iguanas that were introduced to the Fijian island of Monuriki two months ago have been tracked down by scientists and appear to be healthy.
A total of 32 iguanas were microchipped and released, with tiny radio transmitters glued to the tails of 11 for tracking purposes. Nine were recovered on Sunday.
US Geological Survey biologist Robert Fisher reported all had increased in length and lost their excessive weight. A lean diet of native plants had evidently “sorted them out,” he said. There was no evidence of trauma or other health issues.
This is the first time Fiji has bred an endangered species in captivity and introduced it into the wild, with the National Trust for Fiji implementing a 2010 International Union for Conservation of Nature (IUCN) species recovery plan.
Fijian crested iguanas are endemic to only a handful of islands. Peter Harlow, an ecologist at Sydney’s Taronga zoo and member of the program’s steering committee, said the islands had never been connected to a continental land mass, and were formed through volcanic eruptions millions of years ago.
The iguanas’ closest relatives live more than 8,000km away in the Galapagos Islands and south-western North America, making their ancestry “one of the great mysteries” of ecology, he said. “The only possible way [the iguanas] could have reached there was by rafting or floating across the Pacific [Ocean].”
While about 12,000 iguanas live on the protected sanctuary island of Yadua Taba, numbers on neighbouring Monuriki have been in rapid decline. They feed on the island’s native plants, which were severely degraded by forest burning and the introduction of goats in the 1960s by the traditional owners, the Mataqali Vunaivi.
The iguanas had a brush with conservationist fame in 1994, when Steve and Terri Irwin visited Monuriki and Tokoriki to search for the elusive population. During a 12-day stay they encountered only three caged individuals.
Harlow first surveyed the iguanas in 1998 and found fewer than 80 individuals and no juveniles. In 2010 a recovery plan was finally implemented, with 21 iguanas captured and removed over a two-year period by the National Trust of Fiji and taken to the captive breeding facilities at Kula Eco Park.
Eight males and nine females successfully reproduced at the park. At the same time, the Mataqali Vunaivi people began eradicating the goats from the island. Restoration work has led to the recovery of the island’s unique dry forest.
Iguanas play a villainous role in local Fijian mythology, but shifting cultural attitudes have led to a new commitment to conservation. A spokesman for the Mataqali Vunaivi people, Ratu Maika Ratu, called the program a blessing.
“This project has made us realise how important it is to protect the island, for our children’s livelihood in the future and also for this very special iguana, the sea birds and other plants and animals that live in it,” he said.
Fijian crested iguanas are a vivid green, but have the ability to change colour and become very difficult to spot when living in treetops. They grow to about 75cm from nose to tail tip, and have strong legs and sharp claws, making them excellent climbers.
They are also herbivores, eating leaves, fruits, shoots and flowers, and are “vital seed distributors”, Harlow said, digesting plants such as the Pacific hibiscus and Tahitian chestnut, and spreading their seeds across the island.
New and rejuvenated populations of birdlife such as the buff-banded rail and the wedge-tailed shearwater have also been spotted on the island thanks to rejuvenation of the forests.
The director and manager of the breeding program at Kula Eco Park, Ramesh Chand, called it a “proud moment”.
“By allowing us to remove a few of the remaining iguanas and breed new stock from them, the traditional landowners have potentially saved a piece of Fiji’s natural heritage from extinction.”
