The effect of urbanization on animals was the topic of many presentations at this year’s SICB meeting. One difference in the abiotic environment of urban areas is that they are often hotter than neighboring natural areas. Sarin “Putter” Tiatragul and colleagues (Josh Hall, Nathaniel Palik, and Dan Warner) at Auburn University are interested in whether urban environments might influence the nesting ecology and development of anoles. Thus, they set to the field to search for nest sites of the Puerto Rican Crested Anole (Anolis cristatellus).
Putter predicted females would choose warm, open-canopied nest sites at both urban and forested habitats, but that the availability of such locations would not be equal between sites. As predicted, randomly available areas in urban habitat had less tree cover and were warmer than randomly available locations in the forest. In the forest, females nested in locations that were similar to what was randomly available (no preference) in terms of distance to the nearest tree, canopy cover, and nest temperature. However, urban anoles nested in less open areas and closer to trees than what was randomly available in the urban habitat. This resulted in female-chosen nests sites being cooler than what was randomly available.
These findings suggest female anoles in forested areas are not choosing nest sites, probably because the forested habitat is homogenous and provides little variation to choose amongst. However, females in urban areas search out cooler microhabitats possibly to achieve favorable incubation conditions for their offspring. Putter also suggested these females may be simply nesting close to where they normally occur, which is close to trees. Either way, females are using the habitat differently in urban areas and such variation will likely have consequences for offspring during development.