After our early rough days, the weather has calmed and we are traveling beneath relatively sunny skies. On this final leg of Shedd Aquarium’s rock iguana research trip, we’ve ventured to the north Exuma Islands to explore cays where tourists frequently visit and feed iguanas.
The endangered iguanas on these cays have been studied for more than 30 years by Dr. John Iverson of Earlham College. Over the course of his study, rising tourism that results in increased iguana-human interaction and iguana feeding, have had tremendous impacts on these animals. I have had the pleasure of working with Dr. Iverson for several years and comparing our research together has only increased the benefits for the iguanas we’re working to help.
When I started my research in the 1990s, I sometimes spent a full day without seeing another boat. Now, the north Exumas have become popular with fast powerboats from Nassau that can bring up to 200 people per day to observe and feed iguanas.
How does increased visitation affect rock iguanas? The first place that we stopped is my favorite cay to observe behavioral changes. Fifteen years ago, before this was a visited beach, these wary animals were difficult to spot. About six years ago, I noticed iguanas congregating on the beach instead of hiding in the cay’s vegetation. Now, these iguanas approach us looking for handouts: we counted more iguanas on the beach this week then we’d ever seen before.
It only took a few brief years to completely alter iguana behavior that had remained unchanged for thousands of years; Shedd’s work will help us understand whether iguana health could also be impacted. On this trip, Shedd’s veterinary technician, Shelley Hallach, has been collecting parasite samples from individual iguanas. Over time, we hope to understand whether iguanas from fed beaches are transmitting parasites between each other at a higher rate than on cays where the animals are more solitary. We also want to learn whether the bread, meat, and other items that tourists feed these vegetarian animals could impact their long-term health.
At night, a stream of twitters reaches us from one of the cays, where nesting Audubon’s shearwaters call to each other. The biodiversity of the Exumas extends from seabirds and iguanas to tropical fishes darting beneath the water’s surface. At this point in the trip, we’re beginning to tire from non-stop work, but the avian chorus reminds us that we’re truly fortunate to be working on conservation in this region. Soon, we’ll hoist anchor and begin the journey back to the R/V Coral Reef II’s port in Florida. Along the way, we’ll share our final thoughts and future steps with you.