Sister Islands on brink of green iguana invasion

Green iguana on Cayman Brac, just west of Coral Isle in the West End (Photo by Linda Young)

(CNS): As the island-wide green iguana cull gets underway in Grand Cayman, residents in the Sister Islands are being urged to “act fast” to prevent a potential invasion on Cayman Brac and Little Cayman, which poses a threat to the indigenous species on those islands. The number of greens appearing on the Brac is still much lower than on Grand Cayman and even less on Little Cayman, which means that a full-scale cull operation will not work. But the Department of Environment (DoE) says action is required now to prevent the population of greens on the Sister Islands becoming another major problem.

“As it stands now, the green iguana invasion is in its infancy in Cayman Brac and Little Cayman,” said DoE Terrestrial Resources Unit Manager Fred Burton. “However, we can easily imagine a scenario where the tremendous scale of the green iguanas’ overcrowding seen on Grand Cayman could be duplicated in the Sister Islands.”

Burton explained that a mass cull on the Sister Islands is not feasible but teams of trained volunteers, known as “Team Go Green” in Cayman Brac and “Green Iguana B’Gonna” on Little Cayman, are reporting sightings of greens and in some cases culling them.

Rock iguana on Little Cayman

The greens pose a threat to the indigenous rock iguanas (Cyclura nubila caymanensis), as they compete for food and habitat, but there have also been reports of the greens interbreeding with rock iguanas on Little Cayman, something scientists had previously believed was impossible.

Since the greens appeared in the Sister Islands, the DoE has periodically sent its own iguana cull teams in an effort to keep the numbers down but Terrestrial Resources Unit Research Officer Sophie O’Hehir said local people are needed to join in and help stem the potential tide.

“It is not necessary for all Sister Islands residents to catch and cull a green iguana when they see one, but everyone can learn the differences between rock iguanas and green iguanas and pick up a phone to report a sighting,” she said. “It is important to report sightings quickly. Reports more than 30 minutes after a sighting are usually too late to enable volunteers to catch the green iguana.”

Dwayne Seymour, the minister responsible for the environment, warned residents on the Sister Islands that they should take the threat of a green iguana invasion seriously, as he urged people to call in sightings and thanked those already helping in the fight to keep the greens out.

To assist with these reports, the DoE has set up two phone lines to report green iguana sightings.

• The Cayman Brac Wildlife Hotline is 917-7744
• The Iguana Hotline – Little Cayman is 925-7625

Callers are asked to provide as much detail on the iguana location as possible so that cullers can be dispatched swiftly and efficiently.

Meanwhile, on Grand Cayman, just three days into the island-wide cull, the army of registered cullers had removed more than 31,000 green iguanas. If that pace can be maintained, the cull is easily on target to remove the near 1.6 million within the first year.

The DoE had estimated that the cullers would need to remove around 6,000 iguanas daily for it to be successful. On Monday the counting team at the landfill took in almost 14,000 iguana carcasses, followed by over 9,800 Tuesday and almost 8,000 on Wednesday. As cullers begin to settle into the job, the numbers are likely to be less, but it seems that so far the project is on track.

For more information on the Sister Islands green iguana cull effort, including details of how to volunteer for the cull response teams, contact DoE Public Education and Outreach Officer Brent Fuller at 244-5984 or 922-5514, or by email at brent.fuller@gov.ky or at Doe@gov.ky.