The distribution, density and biomass of terrestrial reptiles in Dominica, West Indies

Abstract

Fourteen species of reptiles have been recorded from the island of Dominica, Lesser Antilles. As part of a larger study of the ecology of Dominica's forests, the distribution, density and biomass of three widespread lizard species (Anolis oculatus, Ameiva fuscata and Mabuya mabouya) were estimated in all major vegetation types. No consistent differences between seasons occurred for any of the three species, and at no site was a definite breeding season detected. Densities, estimated mainly by plot counts, were highest in coastal woodlands where mean densities reached 2148 Anolis per hectare, 379 Ameiva per hectare, and 751 Mabuya per hectare. Densities in rain forest sites were often very low. Combined biomass for the three species also reached a maximum in coastal woodlands of 44.7 kg/ha. This value is amongst the highest recorded for terrestrial reptile assemblages, and suggests that Dominica's coastal woodlands are unusually favourable habitats for reptiles.Previous studies of Caribbean lizards have suggested that either competition or predation from birds may influence lizard densities. The present study, however, found no such relationships, and it was concluded that lizard density was independent of bird density.