Meeting Abstract
Predation is a key factor in population regulation and evolutionary processes. For oviparous species with no parental care, vulnerability to predation is critical at the egg stage and female nest site choice can reduce egg predation. Based on observations of square-back marsh crabs (Armases cinereum) eating brown anole eggs (Anolis sagrei), we designed indoor and field experiments to answer three questions: 1) are marsh crabs a major predator of brown anole eggs, 2) does egg predation differ among microhabitat types, and 3) how does crab density affect egg survival? In both experiments, we placed incubating eggs in three different natural and relevant microhabitats: open area, palm frond, and leaf litter. We also manipulated the placement of the eggs as either buried or placed on the surface. Both experiments confirmed square-back marsh crabs as anole egg predators. We also found a difference in egg survival depending on microhabitat type; placement of the egg was crucial for egg survival in the open area microhabitat. Crab density did not affect egg survival in our field experiment. These results suggest that selection of nest site by female brown anoles can affect their offspring survival in the presence of marsh crabs.
