Fig.1) Left: Anolis bimaculatus male (top) and A. leachii male (below) for comparison. Right: adult male A. leachii x A. bimaculatus hybrid.
We all know examples of interspecific hybrids in animals such as the Liger, the Zhorse or the Calico Chuckwalla or even intergeneric hybrids in plants such as orchids. Even within Anolis, there are well known examples of interspecific hybrids such as Anolis aenus x Anolis trinitatis on Trinidad.
I was able to produce fertile hybrids of different members of the bimaculatus group in my breeding facility which I want to show you in this post.
I am a private reptile keeper and breeder and have been working with Lesser Antillean Anolis, mainly in the sense of keeping and breeding, for 20 years. About three years ago, a good friend of mine told me his A. oculatus and A. terraealtae, which he kept together in a small greenhouse, had interbred and produced offspring. This was amazing to me, as I thought they were genetically too far apart. Shortly after that, out of interest and curiosity, I paired up some different species of my collection with the aim to produce hybrids. I was interested if it is possible to interbreed them in general, and also I wanted to see what the hybrids would look like. So in 2020, I paired up …
1) a male A. marmoratus marmoratus with a female A. ferreus
2) a male A. leachii with a female A. bimaculatus
In both cases, I used a large adult male and a young adult female that was raised single and had never been with any other Anolis before. I introduced the female into the male‘s enclosure and in both cases the male started courting the female immediately and mated with her. After the copulation, I separated the female again and collected the eggs over the course oft he next months. Long story short: I was able to obtain viable hybrids, raise some of them to maturity, paired this F1 generation again and produce viable F2 hybrids.
To describe the hybrids, I would say that they are generally very much intermediate in size and color regarding their parent species, both in males and females. But just look at some of the results (above and below):
Fig.2) Left: Anolis bimaculatus female (top) and A. leachii female (below) for comparison. Right: adult female A. leachii x A. bimaculatus hybrid.
Fig.3) Left: Anolis marmoratus marmoratus male (top) and A. ferreus male (below) for comparison. Right: adult male A. m. marmoratus x A. ferreus hybrid.
Now, I have some thoughts about this. We know that genomes diverge in isolation until the accumulated differences result in “speciation“ and/or reproductive isolation, as it is the case with the Anolis in the Lesser Antilles. With the use of molecular clocks such as the cytochrome b mitochondrial gene and geological dates, we can measure the genetic distance and estimate the timespan of separation of these taxa and project their phylogenetic relationships.
But how genetically distant or how long or over how many generations do two species have to be isolated to be genetically incompatible in the sense of not only being recognized as separate species by us, but also not being able to reproduce? Could Anolis be used as a model group for a question like that in general? Which would be the most distantly related Anolis species that would possibly be able to reproduce? Is there any specific pairing that would be of special interest?
Short disclaimer: None of the hybrids will return into nature. They live a healthy and fulfilled captive life like any other captive Anolis. They are just fine and healthy. Please do not blame me for this project.
The 7th annual Puerto Rico Herpetology Symposium will be held in just 3 weeks at the Universidad de Puerto Rico in Arecibo. Although we considered combining our anole meeting with this amazing event, we decided to keep the events separate for logistical reasons (thank you to everyone who so enthusiastically responded!). But that doesn’t mean you can’t still attend the upcoming one-day symposium on the beautiful island of Puerto Rico. This is a fantastic event that features academic and applied herpetological research from across the island. If you conduct your research in Puerto Rico (or would like to) this is a must-not-miss event. There are certain to be many talks and posters on anoles!
Everyone grasps the fundamental concept of a field guide: a book designed to aid in the identification of species in the wild while offering pertinent information about them. Unlike encyclopedias, field guides strive to provide information about EVERY species within a specific animal or plant group in a given geographical area. Field guides can be comprehensive when the number of species covered is limited. For instance, a field guide centered on the crocodiles of the Americas would include only ten species.
However, how do you create a comprehensive field guide about a species-rich animal group in a mega-diverse country?
To answer this question, I will tell you the story of the Reptiles of Ecuador book, a meticulously created field guide that has gained attention due to its expansive scope, novel photographic style, open-access nature, and funding strategy.
The idea for a Reptiles of Ecuador book emerged in 2010 from a casual conversation with a wildlife photographer friend. I posed a question:
Why are there field guides for birds and mammals of Ecuador, but none dedicated to reptiles?
His response was candid: “I’m not sure… you should consider writing one.”
His suggestion caught me off guard. I had never contemplated writing a book and, even though I found the concept intriguing, at 18 years old and just commencing my studies in biology, I did not feel qualified for such a task.
Throughout my childhood, I had drawn inspiration from field guides spanning diverse animal groups, ranging from insects to birds, and more recently, amphibians and reptiles. Consequently, I had a general idea of how a field guide about herpetofauna should look like.
But I had no idea how write one.
How could I possibly compile a book encompassing ALL reptile species within a country as biodiverse as Ecuador? The nation boasts a staggering 500 reptile species!
There are 500 species of reptiles in Ecuador, including the Emerald Tree-Boa (Corallus batesii), a snake that lives in the canopy of the Amazon rainforest and is seen no more than once every few years. Photo by Jose Vieira.
Anolis carolinensis, the Carolina green anole;
Collier county, Florida (15 March 2018).
In Collier county, Florida, many of the Carolina green anoles sport a fairly grayish dewlap, that fold of skin under the lower jaw. Typically, the dewlap for this species is pinkish. Some consider these regionally-focused “gray-dewlapped” green anoles to be a distinct subspecies (Anolis carolinensis seminolus) separated from the rest of the Carolina green anoles, but I’m not sure there’s much data to back up an actual subspecies distinction. Seem to me to simply be a phenotypic variation in that particular stretch of south Florida. I also find more-standard pink-dewlapped Carolina greens cohabitating in the same areas. Regardless of subspecies designations, I do love coming across these fantastic variants in Collier county.
Want to read more about gray-dewlapped A. carolinensis? Check out previous Anole Annals post (this one, which links to two others).
A female A. carolinensis in Ocklawaha, FL moments after laying an egg.
Anyone know of any new phylogeny work on carolinensis? The animals here in Ocklawaha, FL appear so unique. Thin bodied, long limbs. Males are small. I know sagrei pushed them to new heights via rapid evolution, but has this “morph” always been in the forest? Sagrei, I would guess, might be more recent here? Maybe a historic clade that escaped pet trade exploitation? I only see females when they’re down laying eggs. They’re fast and cold give Miami distichus a run for their money.
Last week, I was about to go to work, when I spotted a drama unfolding on my window: a green anole had captured a sphinx moth. Of course, I had to stop and investigate.
Moth predation by anoles is not something worth blogging about in its own right, but this sphinx moth was the size of the anole’s entire body and certainly thicker than its head. These moths are very strong fliers, and the fact that this anole could hold on to it seemed quite remarkable. My bets were on the sphinx moth escaping. And if not, I was sure the anole was not going to be able to eat it.
The anole had other plans.
Soon, another green anole approached with the obvious intention of sharing in its conspecific’s success, but the hunter preferred to dine alone, rejecting the invitation to commensalism. It relocated from the window to the table below and then to an even more secluded spot on the back of a patio chair.
My curiosity piqued, I followed.
The moth eventually stopped showing any signs of life. This was interesting, as sphingids are normally very hard to kill by pinching. Perhaps the beta-defensin peptides that green anoles possess, which are similar to reptile venom, played a role in subduing its prey: the lizard had clearly secreted something while chewing on the moth, as it was quite damp by this point.
To my amazement, the moth began to disappear, heading head-first into the anole’s mouth.
Green Anole that just captured a sphinx moth. Photo by Andrei Sourakov.
Green Anole with the sphinx moth inside. Photo by Andrei Sourakov
The anole was doing the trick snakes pull, which I’d had no idea anoles could do: swallowing something larger than its own head, until the entire moth disappeared.
While I ended up being quite late for work that day, I had a most original excuse: “I was watching an anole swallowing a moth.” If you want to watch it too, you can click on the embedded video below.
P.S. There is a detailed page about green anoles (link below):
In Fall 2011, the International Union for the Conservation of Nature (IUCN) Species Survival Commission (SSC) Anoline Lizard Specialist Group (ALSG) was approved. The group had a good run for several years before entering a period of inactivity. At present, all IUCN activity pertaining to anoles goes through the IUCN Snake and Lizard Red List Authority, rather than an anole-specific IUCN Specialist Group.
Luke Mahler said it well back in his 2012 Anole Annalspost:
Anoles are well-known for a lot of reasons, but conservation is not one of them.
Unfortunately – and despite the deep appreciation and fascination many of us have with anoles – anole conservation still seems to be on the backburner. This does not stem from a lack of caring, but rather from a lack of time. With over 380 anole species described, the lack of an Anoline Lizard SG gives the impression that anole biologists do not care about their conservation. I know this is not true and I am therefore in the process of gauging interest in re-establishing an IUCN SSC Specialist Group that would develop conservation, science, and outreach activities to facilitate the survival of wild anoles in their natural habitats.
Please fill out this short Google form if you have any interest in helping re-establish the IUCN SSC Anoline Lizard Specialist Group.
I would like to underscore that when the ALSG was active, anole biologists contributed to many anole Red List assessments and other important conservation actions for numerous anole species. This was a major improvement compared to what little had been done for anole conservation prior to the establishment of the ALSG. The initial establishment of the ALSG was a huge step in the right direction, but we have to keep going. There remains plenty of action to be taken to conserve anoles, particularly anoles that are comparatively understudied, occur at low densities, have small or restricted distributions, or are actively facing habitat loss, fragmentation, and degradation (and more). Re-establishing the IUCN SSC ALSG will give us a platform through which to build an anole conservation network as we work to improve anole conservation efforts globally.
I would also like to emphasize that our work will not stop at simply re-establishing the SG. We will need to develop goals and objectives for the group and find ways to reach these goals – all in an effort to promote and improve anole conservation. As you all know, there are a lot of anoles species and therefore, we need a lot of people on board!
Yes, Lizards Have Their Own Holiday. Learn Why They Add Color to Our World
A male brown anole extends its bright orange dewlap to signal to another anole. (Photo courtesy of John David Curlis, University of Michigan; illustration by Emily Faith Morgan, University Communications)
Wait, you didn’t know that Monday is World Lizard Day? What rock have you been living under?
To celebrate, two University of Virginia lizard-ologists want you to see these tiny reptiles’ true colors shining through.
There almost aren’t enough crayons in the box to capture the scale of their scaly vibrance. Add to that their amazing ability to sometimes change colors, and you can see how it’s easy to become a fan of the fan-throated lizard, or geek-out over the crested gecko.
Christopher Robinson, a doctoral candidate in the lab of biology professor Robert Cox, is one such devotee. He’s currently a Doffermyre Family Jefferson Dissertation-Year Fellow.
“Lizards are such wonderful organisms to study,” Robinson said. “They can be stunningly beautiful, exhibiting vibrant colors and fascinating patterns that are useful for investigating principles in evolutionary biology.”
Robinson and Cox decoded for UVA Today some of the many colorful mysteries behind lizards’ pigmentation.
Q. Why do lizards around the world vary so much in their colors?
Robinson: The evolution of color is driven by the selective pressures an animal encounters in their environment, and the way that they can be seen in it. For example, the coloration of a lizard in a deeply shaded forest and a species in a bright desert are usually quite different.
Similarly, lizards that are only active at night use color differently than lizards that are active during the day.
At left, Robert Cox is an evolutionary biologist and ecological researcher who runs the lizard lab at UVA. At right, Christopher Robinson is a graduate student in his lab. (Photos by Dan Addison, University Communications)
Two of the biggest drivers of color evolution are predation and social interactions, such as finding a mate or protecting a resource.
All of these selective pressures interact to produce the stunning variation we see in lizard colors around the world.
Q. Is predation the primary driver of why the colors have evolved?
Robinson: For some species, yes, but for others, probably not. While predation is a strong selective pressure, the ability to find a mate is just as important as not being eaten.
Many species of lizards have sexually dimorphic coloration, meaning males and females have different colors. Often, females are less colorful than males. The female coloration allows them to be cryptic and avoid predators, while the vibrant male colors act as signals to mates and rivals.
Q. Does more intense color indicate they’ll taste bad to a predator?
Robinson: In Virginia, we don’t have any lizards that are unpalatable to predators, although we do have amphibians, such as the red-spotted newt, which are bright red as juveniles to warn predators that they contain lethal toxins, which are potent enough to kill humans if they are consumed.
Cox holds a brown anole on his finger. These lizards can rapidly change from dark to light, but their scales essentially still stay brown. (Photo by Dan Addison, University Communications)
Cox: Bright warning colors that signal toxic or unpalatable prey are common in insects and amphibians, but not in lizards or other reptiles. However, bright color can be a warning that a species is venomous.
Gila monsters and beaded lizards of the southwestern United States and Mexico are the only truly venomous lizards, and they are strikingly colored orange and black as a warning.
Q. How does color help with mating?
Robinson: Male lizards often use coloration and colorful ornaments to signal to mates, and in some species, variation in coloration is associated with individual quality. This might mean that the individual is healthy and free from parasites, able to secure food easily, or strong.
In theory, a female can then use coloration to assess whether the offspring she has with a male are likely to be successful themselves.
Q. What are the most colorful lizards we can see in Virginia?
Robinson: The lizard most people contact me about is the common five-lined skink. Juvenile skinks have dark backs with bright yellow stripes and a vibrant blue tail. But as they mature, the blue color in their tail fades, and they tend to lose their yellow stripes.
Male, left, and female, right, desert spiny lizards demonstrate the variety of colors that occur with sex differences. (Photo courtesy of Christian Cox, Florida International University)
However, during the breeding season, adult males develop bright orange heads and enlarged jaw muscles, which they use in fights with other males.
Cox: Eastern fence lizards, which we study, are also very colorful, but you might not know it at first glance.
Juveniles and adult females have subtle brown and black patterns on their backs that help them blend in with tree bark and avoid predators. Even adult males are not particularly colorful from above.
But, if you look at the underside of a male, you will see vibrant blue patches that they display to rival males or potential mates – by doing push-ups.
Q. Why do some lizards’ bodies seem to be segmented into two or more distinct colors?
Robinson: There are several reasons why this can occur, but if we revisit the example of the common five-lined skink, with a striped body and a blue tail, it is primarily an anti-predator tactic.
Robinson, a Doffermyre Family Jefferson Dissertation Year Fellow, discusses aspects of his research. (Photo by Dan Addison, University Communications)
When the lizard moves quickly, the stripes running down its back are disorienting and make it hard for a predator to focus on the body. The blue tail serves as a visual attractant, so that predators are encouraged to attack an expendable body part.
The tail, as you may know can break off, allowing the lizard to escape and live another day while the tail regenerates.
Cox: In other species, the distinct colors may be a way of generating a contrasting pattern that stands out during visual communication with other individuals. Lizards generally do not vocalize, so most of their social communication occurs through visual displays or chemical signals.
Many lizards also have ornaments that are brightly colored and stand out from their background color. For example, we study anole lizards that use an extendable throat fan called a dewlap to communicate with one another. The color and pattern of the dewlap is highly specific to the particular species of anole.
The underside of a male Eastern fence lizard can be an intense blue, which the lizard shows off to rivals by doing push-ups. (Photo courtesy of Christopher Robinson)
Q. What is color-changing used for?
Robinson: Color change is often used as a social signal to indicate something about an individual’s current state. If a male lizard has just won an aggressive interaction with a rival, it may signal this by changing its color to help attract a mate, or to advertise its victory.
Because lizards do not produce their own body heat like birds or mammals, many species also use color change to thermoregulate and control their body temperature.
A lizard that is cold can darken its skin to help absorb more solar radiation and quickly warm up. Once it has reached its optimal body temperature, it can lighten its skin to slow the rate of solar absorption and maintain its preferred temperature.
Contrary to popular belief, there is much less evidence that rapid color changes are used for background matching and camouflage.
Q. What are the biological mechanisms that create the color changes?
Robinson: Different cell types contain different pigments and structures that contribute to color. For example, melanin pigment absorbs light and appears brown or black. Lizards can darken their color by dispersing melanin throughout the cells that contain it, or lighten their color by concentrating the same melanin into a small area of each cell.
Green anoles, one of which is pictured foreground, can change color from brown to green, whereas related species, such as the brown anole in the background, can only change from light to dark brown. (Photo courtesy of Robert Cox)
Color change often involves several cell types. In the green anole, cells that reflect blue light interact with other cells that contain yellow pigment to produce their green color.
Cells containing melanin sit beneath these blue and yellow cells, but they have arms that extend above the other cells to the surface of the skin. When the lizard darkens, melanin disperses to the tips of these arms, covering the other pigment cells and producing a brown color.
Q. How will you be celebrating World Lizard Day?
Robinson: I will be working on my next lizard-based paper and likely watching “Rango” in the evening.
Cox: I’ll use it as an opportunity to read a few recent papers on lizard evolution to find some new material to incorporate into my teaching.
In Fall 2011, the International Union for the Conservation of Nature (IUCN) Species Survival Commission (SSC) Anoline Lizard Specialist Group (ALSG) was approved. The group had a good run for several years before entering a period of inactivity. At present, all IUCN activity pertaining to anoles goes through the 
Cannibalism is