9424471 Alberts Only 60 of the 3,000 species of the extant lizards attain an adult body mass greater than 1 kg. Despite this, large lizards represent over 60% of lizard species considered threatened or endangered. Even among distantly related species, large body size, requirements for tracts of undisturbed ha`itat, and human exploitation for skins and food link large lizards with respect to conservation management strategies. Of all large lizard species, the West Indian rock iguanas, genus Cyclura, are the most endangered, primarily because they inhabit fragile island ecosystems that suffer from habitat degradation and the ill effects of introduced species. Over the past two years, Cyclura species have been studied at the Guantanamo Bay Naval Base in Cuba. This research has led to important management decisions and development of management plans to conserve this highly endangered lizard. As a result of the recent Haitian/Cuban refugee crisis, one of the four originally proposed studies, the experimental reintroduction program, has been postponed. Because of the more than 30,000 refugees currently housed at Guantanamo Bay, field experiments had to be delayed. This research will take advantage of this delay to conduct experiments that will provide direct mechanistic evidence regarding species survivorship following capture breeding and release programs. The release of endangered species from captive breeding programs is often conducted without any scientific rigor. The research in this Conservation and Restoration Biology proposal represents the first rigorous approach to determining the factors that will affect the success of captive breeding prmgrams.
