I have just recently returned back home to Slovenia, where I started a research position at the Jovan Hadži Biological Institute, Research Centre of the Slovenian Academy of Sciences and Arts. Although I have thus far studied topics as diverse as sexual selection (nephilid spiders), phylogenetics (cuttlefishes) and visual gene expression (deep-sea fishes and cichlids), I have always had a keen interest in anole evolution. With the new position in hand and certain questions in mind, it seems that the time is ripe to finally, slowly but surely, delve into anole research.
Topics I am most interested in concern sexual selection and maternal effects, but also phenotypic plasticity in general; the latter also from a molecular (transcriptomic) point of view. Since AA brings together anole researchers of all scopes, I was thinking of asking here directly . . .
Would you be able to point me in the right direction and suggest colleagues and research groups that tackle questions within the scope of the aforementioned topics?
Please don’t hesitate to email me directly (nik.lupse@zrc-sazu.si) if willing to discuss in more detail. Many thanks!
MCZ 36138, the holotype of Anolis roosevelti. Laszlo Meszoly, del. From Mayer and Gamble 2019.
We recently reported on the new U.S. Fish & Wildlife Service review of the status of A. roosevelti (spoiler alert: not good). And we mentioned that we’ve had a lot of posts on this species before, including a number of recountings of previous attempts to find the elusive beast. In turn, this post prompted Ray Huey to recount his own efforts. Here goes:
During my first summer at Harvard (1971), I joined Ernest Williams (my advisor) and two grad students (Preston Webster, Joan Roughgarden) on a trip to the Caribbean. This was my first introduction to the amazing Anolis lizards. We went to the Dominican Republic, Guadeloupe (magnificent), Puerto Rico, and then Culebra–discovered by Columbus–off the east coast of Puerto Rico.
In 1939, the U.S. Navy started using Culebra as a target for bombing practice. But is also the island where Anolis roosevelti, a “giant” anole”–was found, but last seen in 1931. Williams thought we should try to find the beast, even though it had probably been blown to extinction.
We arrived at the tiny town of Culebra Pueblo in late afternoon. The only hotel was full, but we found a small rental house run by Frank Slaughter. Frank was colorful. He had been a boat captain and had ferried Richard Levins and Harold Heatwole around while they were doing biological surveys on small islands near Puerto Rico.
Slaughter had a way with words. He referred to Levins as a “strange duck”: “When I was in high school, people were counting the number of hairs on the asshole of fruit flies. And here was Richard Levins, a grown man, still counting the number of hairs on asshole of fruit flies.”
Given that Levins was one of the premier evolutionary theorists of his era, we all howled.
Back to the business of looking for Anolis roosevelti. Williams asked Slaughter whether he’d seen any big green lizards on Culebra. Slaughter replied, “How big is big? Do you have to reach up to milk it?” Williams (who was usually formal, especially with strangers) was speechless. The rest of us had to work to keep from laughing. All things are relative, but some are more relative than others.
View of the Andean scrubland, the main habitat of the lizards of the Anolis heterodermus group. Credits: Rafael Moreno.
Several years ago, when I began my biology studies, I was taking a walk in an Andean scrubland near my hometown, Bogotá, and while admiring the twisted shapes of the shrub branches, I noticed a small bright-green elongated spot on a branch, which stood out from the surrounding vegetation. The spot looked like an altered vision produced by entheogenic substances. As I approached the spot, my anxiety increased because it was slowly rotating around the small branch while I was getting closer. But when I was close enough to identify it, my anxiety ceased. It was not a hallucination, but a lizard, an Anolis heterodermus!
Some years later, my anxiety returned when I thought about the future of those lizards due to the advance of a gigantic city hungry for concrete. We decided to investigate it by trying to document the dynamics of populations in scrublands surrounding Bogotá. Even though the city continued its inexorable growth, it seemed that these lizards had several strategies to face the loss and fragmentation of their habitat, but only if the urban development onslaught was not too strong. Thus, my anxiety ceased, but only partially.
A small sample of the huge phenotypic diversity in A. heterodermus y A. richteri. Credits: Rafael Moreno.
The dewlap is probably the most noticeable thing about anoles. For me, the best way to spot an anole is by the flash of color from the dewlap as a lizard displays. Without that, many anoles would remain cryptic amongst the vegetation. This seems to be the case for the lizards themselves as well. The burst of color and movement as the dewlap is rapidly extended is a wonderful device for attracting the attention of rivals and mates. It’s possible that the dewlap originally evolved as an attention-grabbing flag to augment an existing sequence of elaborate headbob movements in forested environments. These days, the dewlap is a complex signal component in its own right, often with a dizzying array of colours and displayed using a variety of movements.
Anoles aren’t the only ones with a moveable dewlap. The Southeast Asian Draco lizards have a dewlap, and again to back up the headbob movements that make up their main channel of social communication. There are many other parallels between Draco and Anolis lizards, but the similarities in how they communicate is something that particularly fascinates me.
Early on in my fieldwork with Draco, I started discovering species that didn’t seem to use headbobs as part of their social display. It seemed these species had lost the headbob entirely and instead concentrated all of their communication through the dewlap display. These species are a minority, but not by much. It was a puzzle. These Draco had lost a central and complex element of their communication in favour of something that was seemingly more basic. Communication biologists are often fixated on trying to explain how animal communication becomes more elaborate over evolutionary time, but less attentive to why complexity subsequently becomes lost. These Draco lizards were an excellent case study.
Draco melanopogon (photo above) only communicates using the dewlap, whereas Draco sumatranus (opening banner photo) relies on both headbobs and the dewlap, just like anoles.
After nearly a decade of fieldwork on numerous species of Draco throughout Malaysia, Borneo and the Philippines, my trips stalled in 2020, as did the rest of the world. Celebrities had nothing better to do than write biographies, but my lockdown project was to focus on using the data I already had at hand to finally solve the curious case of the missing headbob.
It felt like an endless series of stay-at-home orders in Australia, and well into 2021 too. While the celebrities had gone on to finish their books and were now doing the zoom promotion circuit, my progress was hurdled by home-schooling two young children. We survived home-schooling in the end, and my attempt at figuring out why some Draco have lost the headbob has finally been published.
The evolutionary history of visual displays in agamid lizards
The first discovery is the headbob display is very ancient, evolving something like 130 million years ago or more. That’s before the evolution of Draco, and before the evolution of the anoles, in an evolutionary ancestor to both the iguanid (new world) and agamid (old world) lizard families. This was back in the age of the dinosaurs. Today, virtually all iguanid and agamid lizards use a headbob display or some variant of it in social communication. Which means the absence of the headbob in a handful of Draco species is very unusual.
The loss of the headbob from the social display of Draco is effectively a loss of complexity. A loss of complexity means a loss of “information potential.” Try writing a biography with half the alphabet. You might manage the following or something a little longer: “I was born. I paid taxes.” Thirteen unique letters in total. Obviously not the rich backstory you might hope for. Not because you hadn’t lived a fulfilling existence; rather you don’t have the language complexity to convey it in detail.
There are various reasons animals might lose complexity in their social signals. Perhaps the original need for a complex signal is no longer present. Perhaps the invasion of a new environment puts a brake on the level of complexity that can be accurately perceived. Or perhaps natural selection on other things, like body size, has made performing a complex signal too costly.
The beauty of having spent so much time in the field is the accumulation of a large library of data. By leveraging this information, I was able to test each of the above scenarios. The short of it is, Draco that have lost the headbob are unusually large species. Physically moving the head and body in a headbob display is more energetically expensive than pumping the dewlap in and out. It seems, then, that the physiological cost of performing the headbob became too great for these large species and they shifted to relying only on the dewlap for communication. This implies the communication system of these species is compromised, unless they have made up the loss of information potential somewhere else.
Draco without the headbob have more complex dewlap colour patterns. Each dot is a different species.
In fact, the dewlap itself tends to be more complex in Draco that have lost the headbob. Stealing a method for measuring complexity of anole displays, the dewlap of these Draco are more elaborately coloured than the average Draco. Unfortunately, this is unlikely to have been enough to fully cover the loss of the headbob. This means Draco that no longer use the headbob are relying on a constrained communication system.
The idea that the headbob is likely to be more energetically expensive than the dewlap was originally proposed for the anoles. It was used to explain the physiological basis for why Jamaican anoles might have evolved an innovation that allowed them to move away from a headbob-centred display in favour of one focussed on the dewlap. To be clear, the Jamaican anoles do still rely on headbobs in their social displays. But a rapid series of dewlap pumps features more prominently in their displays compared to the typical anole, like those on Puerto Rico for example.
It seems the dewlap has begun to supersede the headbob in anoles as well.
If you’d rather not slog through the paper itself, you can view a 12 minute video summary instead. If you would like to slog through the paper and can’t access it behind the paywall, drop me an email and I’ll forward you a free copy (t.ord@unsw.edu.au).
This year the Dutch society for Herpetology “Lacerta” celebrates its 80th anniversary. To celebrate, a lot of hard work has been done over the past year on a special edition of our journal, Lacerta, entirely aimed at anoles. We call it the Anolis special. It has become a 256-page book with contributions from Anolis enthusiasts and connoisseurs from the Netherlands, Belgium, Germany, Finland and Canada. It contains articles about, among other things, the study of anoles, behavior and welfare, travel reports with herpetological observations and species descriptions including the experiences of keeping in captivity.
At the moment the book can be ordered for anyone interested. website: https://nvht-lacerta.nl/.On that website, everybody can order a copy for €20, including shipping world wide.
Anoles are also models for urban evolution. Why? Anoles are found abundantly across the Caribbean in urban and forest environments where they specialize in divergent microenvironments characterized by shifts in climate and physical structure. Urban habitats tend to be warmer, drier, more open, and dominated by buildings and impervious surfaces instead of vegetation — providing the perfect opportunity for repeated adaptation to a novel combination of environmental conditions. In other words, Caribbean cities provide a replicated natural laboratory to study adaptation as it happens when these lizards colonize and thrive in urbanizing areas. And there is no shortage of urban-tolerant and urbanophilic anole species to choose from!
Species of Anolis lizards are found in urban environments across the Caribbean (photos CC-BY K. Winchell; Earth at night by NASA).
I have just published my second anole book, mostly for children with many solid lizard facts most of which I have learned from posts on this website. Grandmothers, here in mid-Florida where I live, love entertaining their young visitors with facts and stories about these curious little creatures. Also, right on the title page of the book, Anatoly announces that he is NOT A GECKO! Ardi Schneider, Vero Beach, FL
I thought you anole lovers might like to read the post I wrote about my research trip to Florida for my book “The Lizard Scientists” for my colleague Caroline Arnold’s blog “The Intrepid Tourist.
A student at the school found this anole egg and showed it to me–great find!
I was hardly a tourist, but rather a lizard-loving author sweating in the Florida sun while observing James Stroud and Kamau Walker capture, measure, take notes, etc. about the anoles living on Jame’s research island in the Fairchild Gardens. There’s a chapter in the book devoted to James’ research.
I also joined photographer/anole researcher Neil Losin to photograph some different anoles near Parkland and visited a school where students gathered population info on anoles on their school ground.
The whole trip was great, and I went home impressed by the hard work and the cheerful enthusiasm of everyone for these lovable lizards.
While hunting sagrei for fun this evening with my 3-year-old, we spotted a large male Anolis sagrei eating what I think is a mourning gecko (Lepidodactylus lugubris). This happened at 7:18 pm in the presence of minimal artificial light from lamps (albeit strong artificial light from my headlamp). Plenty of sagrei were already asleep on leaves. Surprising to find a diurnal lizard preying on a nocturnal/metaturnal gecko.
English translation 
While hunting sagrei for fun this evening with my 3-year-old, we spotted a large male Anolis sagrei eating what I think is a mourning gecko (Lepidodactylus lugubris). This happened at 7:18 pm in the presence of minimal artificial light from lamps (albeit strong artificial light from my headlamp). Plenty of sagrei were already asleep on leaves. Surprising to find a diurnal lizard preying on a nocturnal/metaturnal gecko.