In April 2009, a team from the San Diego Zoo, Fort Worth Zoo and Hope Zoo gathered in Kingston, Jamaica for the annual veterinary health assessment component of the Jamaican Iguana Recovery Program. The Hope Zoo is tasked with the role of raising juvenile iguanas safely in captivity as they grow from tiny hatchlings to a size large enough to contend with non-native predators in their last remaining forest habitat. At least once a year, all the captive iguanas need to be weighed, measured, and evaluated for their health and fitness. Though our time in Kingston was shortened by flight constraints and delays, the team worked long hours to complete the screening for all 170 animals!
In addition to morphological measurements, our exam included collecting a small blood sample from the iguana’s tail vein to determine biochemical and hematological values. It is important that release candidates are in top physical condition since it can be stressful during the first few weeks while the iguanas adjust to their new wild home. A portion of the blood sample was also saved for future genetic research aimed at evaluating diversity, reproductive success, and management strategies for this small population. Another major concern is the potential for transmission of harmful pathogens from newly-released to free-ranging iguanas. For this reason, our health screening also included parasitological tests. Seven males and fourteen females were selected for release this year, which brings the total number of iguanas released in the Recovery Program up to 126!
Once the release candidates passed their health exams, they were transported to the Hellshire Hills, where the last remaining wild and repatriated iguanas live. Faculty and students from the University of West Indies, Kingston, are the lead researchers for the field component of this program. Most iguanas were released in the core area near one of the large open-canopy nesting sites. A few of the largest iguanas were outfitted with radio transmitters and released near the periphery of the core zone, where iguanas are rarely seen. This is the second year we have radio-tracked releases as ‘Judas Iguanas’ in the hope they will lead us to discovery of other wild sub-populations outside of the known core area. Right now the field team, assisted by staff from the Milwaukee County Zoo, is also gearing up their equipment for the arrival of female iguanas at the nesting sites. Among many milestones, we have documented a two-fold increase in the number of wild nesting females since the program’s inception and we are cautiously optimistic about the future of this species!