Colonization and Saturation of Habitats by Lizards

Abstract

We studied the colonization of habitats by four species of iguanid lizard (Urosaurus ornatus, Sceloporus graciosus, S. undulatus, and Uta stansburiana) to determine differences among the species in colonization, differences among habitat types in colonization, and the time trajectory of colonization. We surveyed lizards on eight study plots in three habitats after a density reduction experiment. We discovered no difference among lizard species in their recovery relative to numbers removed. However, there were significant differences in recovery among habitats, suggesting an important role of habitat type in the resilience of the lizards to the perturbation. Colonization by lizards was rapid and most study plots were colonized within 2 to 3 mo of the manipulation. One year after the experiment, all species were represented on all plots. Saturation (ratio of marked lizards to the number removed on each plot) was significantly different between the first and all other post-manipulation census periods. There was no significant difference in saturation among the second (1 yr), third (15 mo) and fourth (27 mo) census periods, suggesting asymptotic saturation within 1 yr of the perturbation. The pattern of colonization by resident lizards was similar to that of all lizards (residents and transients). There was no difference in saturation among species, but there were significant habitat and census period differences in saturation.