Experiments on dispersal: Short-term floatation of insular anoles, with a review of similar abilities in other terrestrial animals

Abstract

The floatation ability of a common Carribean insular lizard, Anolis sagrei, was tested under controlled conditions in a laboratory seawater wave tank. Short-term passive floatation abilities are extensive: all 39 animals survived 1 h, and 30% of those tested were still afloat by 24 h.The survival times for anoles in seawater are much greater than those reported in the literature for the 19 species of small mammals tested in freshwater; only mediumsized mammals have comparable abilities. Floatation, unaided by rafts, is a likely means of dispersal for anoles and perhaps other lizards between nearby islands such as in the Bahamas. The literature on observed overwater dispersal distances in non-volant animals is tabulated; data are rather scarce.