Photographs by Odey Martínez Llanes
Photograph by Odey Martínez Llanes
Photo by Julie Katz
Hard to imagine a more important service than this! Miami resident Julie Katz provides the details: “When I walked out of my condo building one night this past spring to walk my dog I encountered a first – a small lizard feasting on a roach.”
Go anoles!
Anolis porcatus (left) found at a plant nursery in Aruba (right).
It was late December 2018. My partner in work and life, Matt, and I were headed back to Curaçao to conduct some follow-up sampling. We had recently completed a field season in Curaçao where we had discovered three newly introduced gecko species (Behm et al. 2019). Since we had to fly through Aruba to get to Curaçao, we decided when booking our trip to spend some time in Aruba, too, to look around for introduced herps, since that’s one of our favorite ways to spend our time when traveling (we’ve even been known to trick family members into searching for introduced herps while on vacation – e.g., Behm et al. 2018). Aruba and Curaçao are neighbors and since Aruba is even more economically connected than Curaçao, we suspected there may have been undiscovered non-native herps there.
What we did not expect was that in less than 3 days on Aruba, we would find three new non-native species (Anolis gingivinus, A. cristatellus and Hemidactylus frenatus) and document a range expansion for a 4th non-native anole (A. porcatus) already known to be on Aruba (Behm et al. 2022). Even though we focused our surveys on properties like plant nurseries and resorts that had a strong likelihood of harboring introduced species due to their influx of ornamental plant shipments, this was still a very high number of species in a short amount of time.
I wanted to understand how these newly documented species fit within the context of the other non-native herps on Aruba. Specifically, I wanted to understand the circumstances surrounding the initial introductions and the current habitat use of the species on Aruba to assess whether any emergent patterns could be gleaned for Aruba. If so, these patterns may lend further insight into how and why the Caribbean has emerged as a hotspot for species invasions (e.g., Helmus et al. 2014, Perella and Behm 2020, Gleditsch et al. 2023).
What seemed like a simple task ended up being more challenging than expected due to the scant and sometimes contradictory information in the literature surrounding the species introductions. To make sense of it all, I enlisted the help of a brilliant undergraduate in my lab, Gianna Busala, whose tenacity and attention-to-detail made it possible to reconstruct some of the invasion history on Aruba. Our recent publication (Busala et al. 2024) compiles all of what we found about the introduced herps on Aruba.
In conducting our research, there were several issues we encountered.
Photo by Christa Denning (aka, @DenningDesign)
From Twitter
Water anole from the Osa Peninsula, Costa Rica (Photo by Lindsey Swierk)
Written by Andrés Rojo:
The water anole (Anolis aquaticus) is a Costa Rican anole that changes color and pattern in different microhabitats as a form of camouflage to avoid detection by their predators, which include birds like motmots and kingfishers. Because of its body color complexity and rapid color changes, water anoles are great study organisms to use when examining how animal camouflage, social signaling, and visual perception interact.
My research project was inspired by Dr. Lindsey Swierk and her lab’s work on water anole color change and camouflage. I joined the Swierk lab as an undergraduate in February of 2021, as I was interested in tropical ecology and animal behavior. I am also a photo hobbyist and experiment with color and full spectrum photography. Dr. Swierk thought that I would be a good fit with the research team studying water anole colors and patterns. When she told me about it, I was motivated by my enthusiasm for photography and wildlife research to take on the project, especially the idea that I could modify research-grade photos to model how animals see one another.
An example color cloud map showing the colors of a water anole (gray) and its substrate (red) as seen through an avian visual system. The X axis represents a green-to-red progression of colors, and the Y axis represents yellow-to-blue colors. Water anoles do not have UV body colors in the regions measured (dorsal and lateral surfaces). Darker tones indicate more pixels of colors at that location within chromaticity space.
Dr. Swierk and I decided to test whether the body coloration of A. aquaticus would be perceived differently by the visual systems of water anoles’ predators and their conspecifics. We used ImageJ and the micaToolbox (QCPA) to model the two visual systems and apply them to each photo taken in the field. The anole and substrate photos were converted into color maps, which could be compared to determine how much the color of the anole overlapped with the color of the substrate in the visual systems of predators and conspecifics – a measure of conspicuousness of anoles according to both visual systems.
A comparison of body color – background color overlap of water anoles as seen through bird and anole visual models, including males (blue) and females (gold).
Although we found no significant difference in how camouflaged A. aquaticus were perceived by the visual systems of predators and conspecifics, our results suggested that males more consistently color matched their microhabitats compared to females and that females were less likely to color match their backgrounds in their lighter phase, suggesting a sex difference in preferred conspicuity in more exposed habitats. These could present topics for future research into how anoles use color camouflage to avoid being detected by predators.
The ubiquity of Brown Anoles (Anolis sagrei) in Florida means that they are constantly on my mind. Given the proposition that rapid evolution may be important to invasive species success, I was curious to determine if invasive Brown Anoles in the southeastern United States, centered in Florida, have any morphological differences from Brown Anoles in their native range in Cuba. To address this question, I measured museum specimens to compare Brown Anole morphology between their invasive and native range and “go back in time” to see if Brown Anole morphology has changed since their invasion.
As reported in our recent paper, Brown Anoles have broadly similar morphology between their native Cuban and invasive Florida ranges. Additionally, we found no clear evidence of the measured morphological traits changing over time. These results suggest that rapid morphological evolution may not be essential to the success of invasive Brown Anoles.
Abstract:
Understanding why some species and not others are successful global invaders is an important question in ecology and evolutionary biology. There is much debate on the role that rapid post-invasion adaptation plays in the success of invasive species. Here, we investigated signals of rapid and broad-scale morphological evolution in Anolis sagrei (Brown Anole) between their invasive and native distributions. Although we found significant differences in a few morphological characters between invasive and native Brown Anoles, the morphological variation present in the species broadly overlapped between both populations and has not significantly changed over the last century. These results suggest the invasive success of Brown Anoles in Florida may not be due to major evolutionary change from their Cuban ancestors.
Researchers have thought of putting anoles in experimental wind tunnels. Perhaps this is the next best evidence? Or maybe this was a setup? Either way, we can see the classic anole response to falling.
h/t Mike Whitlock
Anolis sagrei from the Bahamas
A dozen years ago, Jonathan Losos explained in these pages how lizards sometimes end up with multiple tail tips, a phenomenon known as tail furcations. My student Tim Baum and I recently published a review of this phenomenon for all lizards and found that published reports of tail furcations exist for 250 species! For the readers of Anole Annals, I wanted to present a quick review of this phenomenon in the genus Anolis.
Among the many lizard records we located were only ten species of Anolis (4% of the total), slightly below the expected proportion of Anolis out of all lizards (6%). But these anoles do have a nice variety of multi-tails! Overall, they conform to the concept that two tails are the most common occurrence (64% of known anole cases). Two-tailed lizards can be divided into those who have a forked tail that is less than half the tail length (i.e., the extra tail starts nearer the tail’s end), which is known as a bifurcation. The other option is that the additional tail begins closer to the beginning of the tail, and this is known as a duplication. Duplications are relatively rare in Anolis, with only 22% of the two tails originating close to the body.
What is interesting about anoles is that aside from two-tailed lizards, three tails are known from Anolis equestris and A. grahami, and there is even a four-tailed A. sagrei! Most lizard genera stick with the two-tailed version, so anoles have it going on!
Clearly, with well over 400 species of Anolis listed in the Reptile Database (and I don’t want to quibble about genus assignments here), many more species should be out there with furcated tails. Based on our research and literature review, these encounters are serendipities of fieldwork, so keep your eyes open and mobile phone cameras ready – and then publish the new records!
