Evaluating Tourism and Food Supplementation Effects on Iguanas of the Exuma Islands, Bahamas (Cyclura cychlura figginsi, C. c. inornata)
Iguanas of the Exuma Islands, Bahamas (Cyclura cychlura figginsi, C. c. inornata) are listed as critically endangered and endangered, respectively, by the International Union for the Conservation of Nature (IUCN). Both are CITES Appendix I species. The population of each subspecies is fragmented and numbers less than 2,500 animals. Tourist visitation and food supplementation is an increasingly popular pastime in the Exuma Islands, and is a potential threat to both individual and population health of the iguanas. Anecdotal evidence of behavioral and physiologic (e.g., fecal quality) changes support this concern.
To assess the impact of tourist activities on these iguanas, behavioral trials, morphometric measurements, and physiologic parameters were evaluated for animals (total n>150) on five islands (no tourism, n=2; tourism, n=3). Iguanas were captured and a blood sample was collected within 3 min from the ventral coccygeal vein. An aliquot was immediately analyzed for glucose, sodium, potassium, ionized calcium, hematocrit, hemoglobin, pH, partial pressure of carbon dioxide, partial pressure of oxygen, total carbon dioxide, bicarbonate, base excess, and oxygen saturation with an i-STAT® analyzer and CG8+ cartridge (Abbott Point of Care, Inc., Princeton, NJ, USA). The remainder of the sample was placed in lithium heparin tubes on ice for later complete blood counts with the Avian Leukopet™ (Vetlab Supply, Palmetto Bay, FL, USA) and collection of plasma. Plasma analyses included a standard reptile biochemical panel (glucose, sodium, potassium, calcium, phosphorus, total protein, albumin, globulin, cholesterol, uric acid, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase), protein electrophoresis, 25-hydroxyvitamin D3, vitamin E, vitamin A, beta-carotene, trace mineral panel (cobalt, copper, iron, manganese, molybdenum, selenium, zinc), and corticosterone. A second blood sample was collected 30–45 min after capture for evaluation of glucocorticoid stress response. Behavioral and physiologic data were analyzed for differences based on island, intra-island location (i.e., central area vs. periphery), and sex. Results will inform future conservation management plans for iguanas in the Exuma Islands.
The authors wish to thank John G. Shedd Aquarium, Brookfield Zoo, University of Illinois College of Veterinary Medicine, Dr. L. Michael Romero, Dr. Lisa Naples, International Iguana Foundation, Heska Corp., and Abaxis, Inc. for their support of this project.