22 October, 2019

Surveys of Grand Cayman’s green iguana population completed in August, have shown a precipitous drop in the number of the invasive creatures still living here, based on Department of Environment (DoE) and U.S. Fish and Wildlife Service estimates.

Using data collected in August, via a distance sampling method developed by Dr. Frank Rivera-Milan, the remaining green iguana population on Grand Cayman was estimated at between 60,000 and 145,000. A year ago, the green iguana population was estimated at between 1.1 million and 1.6 million.

“That would equate to a 92 percent reduction in the green iguana population since the cull project began in October 2018,” said DoE Terrestrial Unit Manager Fred Burton.

However, Mr. Burton emphasised that the August surveys would not have accounted for the green iguana hatchlings that began to emerge around that time or later in the year. Over the past several weeks, the green iguanas brought to the George Town landfill have mostly consisted of hatchlings (see the attached chart regarding iguana cull counts).

“We have no direct measure of the number of green iguana hatchlings that have emerged this year,” Mr. Burton said. “Their emergence represents the reproductive output of the breeding green iguanas nesting earlier in the year, at a time when there were many more surviving adults than there are today. This emergence was inevitable and expected. It has also likely put the total number of green iguanas significantly above the August population estimates.”     

“Our green iguana cullers have done a great job thus far,” Minister of Environment, the Hon. Dwayne Seymour said. “However, we must keep focused on the job over the next few months so the breeding green iguana population doesn’t rebound next summer.”  

Although more than 500 individuals, teams or companies have registered for the cull, registration continues to be open for Caymanians during working hours (i.e. between 8am & 5:30pm, Monday – Saturday), at the green iguana counting station located near the entrance to the landfill. Cull training opportunities are also available for Caymanians who wish to become cullers. Please contact Cornwall Consulting at 949-1544 or 769-8888, or [email protected] for more information.

If you have general questions about the green iguana cull, please contact DoE Public Education and Outreach Officer Brent Fuller via phone at 244-5984 or email [email protected].

IMAGE: Caption for graphics: The pie charts show the age breakdown for green iguanas turned in at the George Town landfill in June 2019 and September 2019.