Searching for anole eggs
In this southern city where the heat is on, and the parties last ‘til the break of dawn, residents are busy patrolling territories, showing off their physique, and courting each other. With all this activity going on, South Miami, FL surely takes the crown for the best people anole-watching destination. All these anoles surely have different stories for how they got to Miami, and some research has shed light on this issue. But what is unknown about anoles in this city is how they manage to proliferate when the temperature can be unforgiving to developing embryos (Sanger et al. 2018; Hall and Warner 2018).
Anolis lizards have attracted the attention of many anolologists that are mesmerized by their conspicuously beautiful dewlap displays, superb clinging abilities (Donihue et al. 2018; Winchell et al. 2018), and an urge to show off their physiology (Battles and Kolbe 2018). However, one aspect of their biology that is much less conspicuous is their nesting behavior. Even biologists that have devoted countless hours studying their behaviors know very little about where females lay eggs, what microhabitats they prefer, and how those nesting behaviors impact embryonic development. In this recently published study, we unveil the mystery of where these city slickers’ nests are located compared to their forest-dwelling counterparts.
Previous studies indicate that crested and brown anoles can withstand putative nest temperatures in urban areas (Tiatragul et al. 2017); however, microenvironment data from real nest sites are virtually non-existent. The only quantitative description of crested anole nests was written by Stan Rand in 1967, and no formal study has been conducted to describe the nest sites of crested or brown anoles. Nesting is a fundamental component of reproduction, and colonization of urban areas by these anoles. Hence, knowledge of their nesting behavior can improve our understanding of how species colonize novel environments.
In this study we characterize anole nest sites in a suburban and a forest site for comparison. We found nests by selecting 80 small plots randomly scattered across the landscape, getting down on our hands and knees, and searching for eggs. Once nests were found, we recorded temperature using a temperature logger, collected weekly data on substrate moisture, measured distance from the plot to the closest tree, and calculated canopy openness (inverse of shade cover). In total, we found 22 nests in the suburban site and 40 nests in the forest site.
We found that nest temperatures in the suburban site are generally warmer than those in the forest and experience greater daily temperature fluctuations due to lower shade cover. While the mean temperature between sites differed by < 2°C (26.8°C forest to 28.4°C suburban), the maximum temperature recorded differed by > 6°C (33.0°C forest to 39.5 °C suburban). Substrate moisture level also tended to be greater in the forest than in suburban area.
We also evaluated the suitability of temperatures used in published incubation experiments with anole species found in our study site. Using this information from published literature, we found that most egg incubation experiments use ecologically relevant mean temperatures but lacked realistic daily fluctuations.
Now that we have an idea of what real nests are like, the follow-up project will assess the consequence of these maternally-chosen nest conditions on embryo survival and hatchling morphology. Only those who can withstand the heat (with a little help from mama) can go out and continue to light up the streets of South Miami, FL.
- Where Do Anolis Lizards Lay Their Eggs? - February 8, 2019
- Anole Embryos Don’t Mind the Heat - March 26, 2017
Stephanie Florio
I have made a lizard habitat in my Florida room outside I’ve planted succulents particularly the pencil cactus overnight I get hatchlings on the inside of the Florida room I would love to see the nest of a lizard I know they probably are laying eggs under the pencil cactus because it provides shelter and camouflage what do I look for to find a nest?