How to catch an iguana
Few people can put “iguana-catcher” on their resume, but six Denison students became experts early this summer during a research trip to the Bahamas. There, they participated in the longest-running known study of iguanas under the tutelage of Geoff Smith, associate professor of biology and amphibian ecologist.
Accompanying Smith were Lenny Mills ’11 from Pittsburgh; Caitlyn Bingaman ’12 from Charlotte, N.C.; Hallie Singer ’12 from Granville; Annie Harmon ’13 from Elkins, W.Va.; Katie Huff ’13 from Chagrin Falls, Ohio; and Skyler Jordan ’13 from Gahanna, Ohio. They joined a fellow research group from Earlham College led by biology professor John Iverson, who launched the study in 1980 (about six years before Dr. Smith became one of his students at Earlham).
The team flew to Nassau and boarded a 68-foot boat with room enough to sleep researchers and crew, and then sailed through the Exumas, a chain of more than 360 cays (small islands) that stretch for about 130 miles. Their destination was the group of Allen, Leaf, and “U” cays — home to a rare subspecies of Cyclura cychlura inornata, or the Allen Cays Rock Iguana.
Allen Cays Rock Iguanas measure about 18 to 20 inches long (not including their tails) and weigh about 10 pounds, much of which is muscle as the students learned. Grabbing some of the reptiles was relatively easy – just drop a net on their head. Others had to be dug out of burrows (with gloved hands), caught with nooses, captured in have-a-heart traps, or corralled like an old-fashioned cattle round-up, with eight or nine people encircling them, walking closer together until they were near enough to dive and clutch.
The researchers fanned out across all three cays, catching as many iguanas as they could (472, to be exact), marking, measuring, and weighing them. About 90 percent of the sample had been marked on previous expeditions, which helped the team measure growth, survivorship, and population rates.
Along the way, they discovered plenty of interesting iguana lore. The lizards feast on grapes, their nests require sandy ground, and they are very attracted to the color red. (So don’t wear red toenail polish when iguanas are around.)
Some populations of endangered iguanas are rebounding, but they still need to be protected from poachers and non-native predators like feral cats and rats. Local people are learning that the iguanas are good for eco-tourism. As many as 150 to 200 tourists come through the islands daily, but these tours can bring their own problems. Nests can be inadvertently trampled, and tourists sometimes give the iguanas unhealthy food. The researchers now encourage area guides to instead offer the scaly lizards fruit and veggies – much closer to the natural diet — as one more way to protect these special animals.