I just returned to Los Angeles from two weeks of fieldwork in Miami. You’ve already heard about one of my adventures, but most of my fieldwork isn’t quite so glamorous! Instead of fishing for lizards with celebrities, imagine long days in the muggy heat of Miami, catching dozens of lizards and getting pooped on by most of them.

Last year at this time, I was dismayed to find that one of my study species, the Puerto Rican crested anole (Anolis cristatellus) was largely absent from the areas where I had expected to find it. This was a problem for me, since I study the interactions between the crested anole and another non-native, the Cuban brown anole (A. sagrei). Initially, my fear was that the dramatic cold snap that occurred early in 2010 might have wiped out one of my two study species!

Luckily for me, however, I was finding plenty of crested anoles by mid-May, so I began to suspect that crested anoles simply became active later in the season than brown anoles. If so, this could provide an interesting opportunity: I could test whether brown anoles exploited the available habitat differently before and after the “emergence” of crested anoles. Data from this natural experiment could help me understand how (and if) the two species were competing.

Of course, field research never goes quite as planned, and when I returned in April this year, the crested anoles were actually very active! The suppressed or delayed crested anole activity that I observed last year might have just been a fluke, brought on by the unusually cold winter.

But because fieldwork is full of unexpected turns, I had a backup plan for this visit. I wanted lay the groundwork for a large experiment I’ll be running this summer. In this experiment, I’ll basically try to accomplish what the cold winter of 2010 did for me: I’ll remove all the individuals of one species from an area, and observe the effects of this removal treatment on the remaining species. And unlike the cold snap of 2010, I can control which species are removed from different plots of land.

A critical part of this experiment is having a marked population of lizards. I’m focusing on males, because they defend territories aggressively against other males (and I’m interested in territoriality, among other things). So my goal on this trip was to find a site appropriate for my removal experiment – an area with approximately equal numbers of brown and crested anoles – and to mark as many males as I could. I settled on a roughly 500-meter stretch of canal-side parkland in South Miami.

In my previous experiments, I’ve never needed males to be marked for more than a few days at a time. So I could just use a paint pen to give each male a unique number – a male would lose this marking when he shed his skin, but generally I was finished with him before that happened. For this summer’s experiment, however, I need markings that will remain identifiable for much longer. Nate showed me a technique that he’s used for identifying his Podarcis lizards in Spain: using a loop of surgical suture, Nate attaches a series of colored beads to the base of each lizard’s tail. Like the colored leg bands often used to identify birds, the sequence of colors in this bead marking will serve to identify each male. With a few small modifications, Nate’s technique worked great with anoles!

Over the course of about a week, I marked 133 male anoles, and I managed to re-sight most of them in the same area where they were initially captured. The markings don’t seem to bother them in the least; I observed males performing all their usual behaviors, including copulating with females, in the days following their re-release. With any luck, I’ll be able to find most of these males again when I return in June, and there won’t be too many new individuals to mark! I know I didn’t get all the males in my study site, but I think I got most of them. And I should be in a good position to start my removal experiment in June!