Despite the widespread use of anoles as model species for ecology, evolution, and behavior, we still have a relatively poor understanding of their nesting behavior and the factors that contribute to egg survival. This is unfortunate because past research demonstrates that egg survival can drive important measures of population demography (e.g. adult population density, Andrews 1982). Andrew DeSana, an undergrad from Seton Hill University, teamed up with the Warner lab to explore the possibility that marsh crabs (Armases cinereum) might serve as predators for brown anole eggs (Anolis sagrei). Because nest site selection by females may shield developing eggs from predators, he also wanted to know how several common nesting microhabitats might influence the depredation of eggs. He used both a lab and a field study to assess how the density of crab predators (no crabs, low crab density, and high crab density) and the nesting microhabitat of females (open sand, under palm fronds, and under leaf litter) might influence egg survival. He collected eggs from a breeding colony of anoles and placed them in these microhabitats in the presence of varying densities of crabs.
He found that marsh crabs readily prey upon anole eggs and that variation in egg survival was best explained by both crab density and the microhabitat where eggs develop. In both the lab and field study, eggs had the highest survival when placed under leaf litter and lower survival in the open and under palm fronds. Anecdotal data of crab behavior suggests that they don’t forage in the leaf litter and this may explain these results. Egg survival also decreased with increasing crab density. Thus, females nesting in leaf litter in habitats with low crab density would have greater reproductive success than those nesting in other microhabitats, especially if crab density is high. Future research will determine how the presence/absence of crabs influences female nesting behavior.
Andrews, R.M., 1982. Spatial variation in egg mortality of the lizard Anolis limifrons. Herpetologica, pp.165-171.
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Dina Vaught
I read your study on the Green Anole. I rescued one about 3 months ago after my cat caught it. Fortunately I stopped my cat from eating him. Apparently, my cat blinded him completely when he bit his head. My Anole was dark brown for the last 2 months and would only turn green when he was asleep. But, over the past month after handling him and putting him on my shoulder, he has turned green again. Only green when he is on my shoulder and when he sleeps at night. I find this very interesting. I think it’s a form of affection and that he feels comfortable on my shoulder now. When I try to put him back in his cage, he grabs onto my finger and doesnt want me to let him go. Then he turns dark brown again after I let him go. He now stays on my shoulder most if the day as I have realized he is green when he is most content. I don’t know if this helps your study on why Green Anole turn different colors, but I believe feeling content and therefore turning green should be mentioned.