From a thriving past to an uncertain future: Zooarchaeological evidence of two millennia of human impact on a large emblematic lizard (Iguana delicatissima) on the Guadeloupe Islands (French West Indies)

Among the lizards in the Lesser Antillean Islands, iguanas are undoubtedly the most emblematic, especially the endemic species, Iguana delicatissima. However, although much effort is currently made for the conservation of this species as a result of the present biodiversity crisis, nearly nothing is known of the history of this animal on these islands during the last millennia. Here we present the first data relating to the distribution, morphology, and interaction of past iguanas with human populations in the Lesser Antilles. To do so, we review the archaeological Iguana remains collected over the past 15 years on the Guadeloupe Islands. Our results show that the only Iguana species occurring in pre-Columbian archaeological deposits is Iguana delicatissima. Moreover, we demonstrate that this species occurred on all the islands of Guadeloupe during pre-Columbian times and then suddenly became extinct between 1960 and 1990 on most of these islands. We also confirm the modern introduction of I. iguana to the Guadeloupe Islands. In addition, zooarchaeological research demonstrates that pre-Columbian human populations occasionally used iguanas as a source of food, but with no apparent impact on the native population. However, the first data relating to past size variations of I. delicatissima on the Guadeloupe Islands indicate that archaeological iguanas were much larger than the largest remnant modern specimens and that a marked decrease in body length (more than 20%) occurred in these lizards after contact with European populations. This evidence of widespread extinction and morphological change during modern times is another demonstration of the extensive effects of disturbance and selection induced by modern human societies on endemic insular faunas.