The Ecological Correlates of Survival in Some Bahamian Anolis Lizards

Abstract

The relationship of survival to size, sex, age and habitat in 4 spp. of Bahamian Anolis lizards [A. sagrei, A. carolinensis, A. distichus, A. angusticeps] is reported. Lizards on a small island having relatively few bird species survived better than those on large islands with many; survivorship in the former area is more similar to that among temperate mainland lizards than among tropical mainland lizards. Survival on 2 islands with different numbers of lizard species but similar numbers of bird species was similar. In A. sagrei, survival was greater in forested than the less protected open habitats. In A. sagrei but no other species, males survived less well than females; A. sagrei is the most extreme territorial polygynous species of the 4. In a univariate analysis, little relation of survival to size was found in any species. Survivorship curves are extremely straight on a semilog scale, indicating constant age-specific mortality. However, a multivariate analysis for A. sagrei, using different data than for the survivorship curves and considering size rather than age, suggested a 3-way interaction between size, habitat and island. On the island with the fewest bird species, but on no other, large individuals of both sexes survived better. The significance of this result for Selander''s hypothesis concerning selection for sexual size dimorphism is evaluated.