I recently received an email from Chris McMartin, the director of the Southwestern Center for Herpetological Research, about a population of brown anoles near his home in Montgomery County, Texas, just north of Houston. Chris has done a lot of preliminary research to understand how the Montgomery population is spreading, and would like to know how these lizards are related to the larger population in Harris County.

Interested? Keep reading!

With Chris’ permission, I’ve copied part of his email below:

“I’ve been casually (in my free time, mostly in the summer) researching Brown Anoles (Anolis sagrei) and their spread in southern Montgomery County where I live.  As I amass observational data, I’ve noticed the lizards are abundant in some yards/neighborhoods, but nonexistent in adjacent yards/neighborhoods.  I’m slowly trying to piece together additional factors (presence of outdoor cats, prevalence of certain landscaping features including decorative rocks and tropical plants, age of house/neighborhood, use of pesticides, etc.) which may explain not only the disparity in abundance but provide clues as to how to control their expansion.

One big question I have is whether the lizards are naturally expanding from a single introduction long ago (e.g. rapidly moving northward from Harris County, where they occur in densities many times higher than the highest I’ve observed in Montgomery County), or are an amalgamation of numerous discrete introductions (e.g. when a home installs new tropical plants from a nursery/home improvement store).  Brown Anoles first showed up in my yard a little over a year ago, marking an expansion northward of about ¾ of a mile from my previous northernmost observations the year prior.

I have corresponded with Dr. Benson Morrill, who owns Rare Genetics Inc. offering DNA analysis for (at this time) colubrid snakes (primarily for sex determination) and inquired as to the possibility of sending him samples from various neighborhoods in my area in an effort to determine whether they represent a contiguous related population or are the result of discrete introductions.  He says the process to conduct this analysis would be cost-prohibitive for a private individual such as myself, but perhaps a university student would like to take on the project.

As it is, I currently spend what surprisingly-little free time I have in the summer exploring neighborhoods in my neck of the woods and documenting my obervations—around 60 hours this past summer between field work and analysis—and I’m approaching my limit of resources in time (and definitely money, if considering DNA analysis as part of the project). This is where I think perhaps a graduate student might be interested in taking on a study of Brown Anoles as a thesis project…lots of possible threads to pull (competition with natives, rate of range expansion, effect of occasional hard freezes on population, etc.).

I’ve published articles in local magazines/newspapers about the lizards and have a public-opinion survey from a year ago (still awaiting analysis) trying to find any links between various conditions (age of neighborhood, presence of outdoor cats, etc.) and occurrence/prevalence of browns, especially with respect to A. carolinensis.  Some interesting things seem to be occurring.  Anecdotally, browns are eating greens (hatchlings), Broad-headed Skinks are eating browns, and greens are eating the skinks (with photographic evidence)!  Sort of a three-way lacertilian arms race.”

If this sounds like just the opportunity you’ve been looking for, contact Chris at yall [at] mcmartinville.com.

mjohnson216
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