Lizard flotilla delights scientists

A raft of debris that apparently floated from Guadeloupe to Anguilla caused a flurry of excitement in the scientific community because of the freeloading passengers that had gone along for the ride. Fifteen green iguanas, clinging to floating logs, survived the 200-mile passage, which occurred after a hurricane in September 1995. This journey was the first of its kind to be documented and reportedly proves the theory that animals could have spread to the islands over water.

"This mass invasion of these iguanas verifies the theory that whole populations of invertebrates can populate islands by over-water dispersal," said Dr. Ellen Censky, director of the Connecticut State Museum of Natural History at the University of Connecticut and author of a report published in October in the scientific journal Nature that details the significance of the voyage.

The mass of uprooted trees and other debris took one month to cross the stretch of water between Guadeloupe and Anguilla, a journey that would likely have killed most mammals, according to Censky, which perhaps explains why the northern Lesser Antilles are populated mostly with reptiles and birds. "Reptiles are good candidates for this sort of dispersal because they can go for so long without feeding. Mammals need to maintain a metabolic rate, whereas reptiles can lower their rate," Censky said. Large populations of mammals could not survive this long without feeding, Censky explained.

Four years later, several of the invading green iguanas have survived, according to Censky, and are still seen by local fishermen, who periodically report to Censky. There was previously no population of this large type of lizard (Iguana iguana, bluish-green in color and four feet long); rather, there was only the brownish iguana, Iguana delicatissima on the island of Anguilla.

Mariners crossing oceans who spot populations of immigrant lizards or other wildlife exhibiting a tendency toward manifest destiny can report to Censky at the Museum in Storrs, Conn.

By Ocean Navigator