San Diego, California - The population of the critically endangered Jamaican iguana is on the rise, thanks in part to the efforts of San Diego Zoo Global and the Fort Worth Zoo. Earlier this year, Tandora Grant, a scientist at the San Diego Zoo Institute for Conservation Research, co-led the health checks of Jamaican iguanas that were head started in managed care at the Hope Zoo in Kingston, Jamaica.

The health checks determined that 37 of the 232 Jamaican iguanas at the Hope Zoo were healthy and large enough to be released back into their native habitat in the Hellshire Hills, on the south central coast of the island. This year’s health screen and release was assisted by returning volunteers from the Audubon Zoo.

The release, which took place in March 2016—20 years after the first release—marks a milestone for the Jamaican Iguana Recovery Group, as the number of animals returned to their native habitat has passed the benchmark of 300 and now totals 315. The Recovery Group is a coalition of local and international collaborators, currently led by the Jamaican government’s National Environment and Planning Agency, and includes the field component leads from the University of the West Indies.

The Jamaican iguana population experienced a drastic decline in the past century, due to habitat destruction and predation by free-ranging non-native cats, dogs, pigs and particularly mongooses. The mongooses and cats attack nearly all hatchling and juvenile iguanas, and there are ongoing efforts to trap these predators to protect the now-recovering Jamaican iguana population.

The headstarting program collects iguana hatchlings from the wild as they emerge from their nests, and cares for the animals until they are large enough to defend themselves from most of the introduced predators in their native habitat. Typically, the iguanas released are between 5 and 8 years old. The population is now increasing—measured by the number of annual hatchlings counted and an eightfold increase in the number of nesting female Jamaican iguanas observed, compared to the first survey of the species in 1991. Before the Jamaican iguana’s rediscovery in 1990, it was thought to have been extinct, since the last confirmed observation had been in the mid-1940s.

An off-island breeding population of Jamaican iguanas is cooperatively managed by members of the Association of Zoos and Aquariums’ (AZA) Species Survival Plan program, as an assurance against a catastrophe in the iguana’s home. Member zoos contribute essential funds, staff hours and expertise for the recovery program, as well as raising awareness for the iguana, its unique and threatened habitat, and the role it plays in the health of the forest. AZA zoos and wildlife conservation organizations have directly contributed more than $1 million toward the recovery efforts in Jamaica since the iguana’s rediscovery.

The first hatching of a Jamaican iguana at the San Diego Zoo Institute for Conservation Research occurred Aug. 30, 2013 at the Kenneth and Anne Griffin Reptile Conservation Center, an off-display breeding facility at the San Diego Zoo Safari Park. The female, named Fay, is a second-generation captive-bred animal. His parents hatched in the first successful breeding of the species at the Indianapolis Zoo, in 2006.

Bringing species back from the brink of extinction is the goal of San Diego Zoo Global. As a leader in conservation, the work of San Diego Zoo Global includes on-site wildlife conservation efforts (representing both plants and animals) at the San Diego Zoo, San Diego Zoo Safari Park, and San Diego Zoo Institute for Conservation Research, as well as international field programs on six continents. The work of these entities is inspiring children through the San Diego Zoo Kids network, reaching out through the internet and in children’s hospitals nationwide. The work of San Diego Zoo Global is made possible by the San Diego Zoo Global Wildlife Conservancy and is supported in part by the Foundation of San Diego Zoo Global.