Screenshot from https://www.instagram.com/reel/DCnjCxhJmVS/

Read about Steve Nielsen, the artist, here.

Distribution of sampling localities for individuals included in our breeding experiment. A Male slender anole dewlaps come in two morphs: solid and bicolor (photographs taken by John David Curlis). B Sampling localities in the Canal Zone of central Panama and associated morph frequencies of males in those populations (circle size corresponds to relative sample size from each site). The frequency of solid morph individuals generally declined from the Pacific to the Caribbean versant of Panama. C Sampling localities for individuals included in our Poolseq experiment. All these individuals were collected along a central trail that bisects Soberanía National Park, near the town of Gamboa.

Color us intrigued! In the world of Anolis lizards, the dewlap—a colorful throat fan used for communication—is one of the most iconic features. It’s been flaunted, flashed, and filmed in countless studies of behavior and adaptive radiation. But for all the attention it gets, we still know surprisingly little about how this flashy ornament is inherited at the genetic level.

Enter the slender anole (Anolis apletophallus), a small but charismatic lizard that ups the dewlap drama with a striking polymorphism. Males come in two distinct throat flavors: the “solid” morph, sporting a fully orange dewlap, and the “bicolor” morph, featuring a mostly white dewlap with a splash of orange at the base. What’s behind this variation?

To find out, we set up 99 crosses (yes, 99!) using individuals from populations that were either monomorphic (fixed for one morph) or polymorphic (home to both morphs). The results? A classic Mendelian plot twist. The dewlap polymorphism in this species is likely controlled by a single autosomal locus, with the solid orange morph dominant over the bicolor version. Simpler than we expected—but the story doesn’t end there.

Pooled sequencing revealed a strong candidate locus (single-minded 1, SIM1) that may underly the slender anole dewlap polymorphism. A Manhattan plot illustrating genomic differentiation between the dewlap morphs using pairwise FST values, and B Fisher exact tests. The red lines in B and C represent the Bonferroni correction (p value= 8.9), with points above the line indicating significantly differentiated SNPs across the slender anole genome. C One locus on scaffold 3, the transcription factor SIM1, contained a peak of many highly differentiated SNPs between morphs. The vertical green bars in the inset represent exons and the arrow represents the direction of genome annotation. D Nucleotide diversity (π) of SIM1 for the bicolor (green) and solid (brown) dewlap morphs. Note that nucleotide diversity was often higher in the dominant solid morph. E SNP panel showing segregating alleles in all significant SNPs (n = 175) in the candidate region of SIM1 for each morph plotted as a heatmap. We denote ref/ref in green representing that solid morph individuals were fixed for one allele and alt/alt in purple indicates that bicolor individuals were fixed for an alternative allele. Ref/alt in blue represents more than two alleles segregating at that position for either the solid or bicolor population. F Male slender anole dewlaps come in two morphs: solid and bicolor.

We also dove into the genome using pooled sequencing (Pool-seq) to search for regions associated with the trait. Our outlier analysis spotlighted a single genomic region with a strong signal—and within it, a prime suspect emerged: single-minded 1 (SIM1), a transcription factor with a flair for phenotypic control. Could this be the mastermind behind dewlap color in slender anoles?

The plot thickens, and we’re excited to keep unraveling the genetic threads behind one of the most iconic signals in lizard evolution. Stay tuned!

Link to the paper just published in Heredity.

Photograph by April Brown

Anole Annals has featured a series of posts on three-legged lizards over the years (e.g., here and here). Now we need help. Some time around 2017, April Brown contributed a photo of a brown anole missing both of its forelegs. The photo was taken in Winter Park, FL. We’d like to contact April, but can’t locate her. Can anyone solve the mystery?

A clip of a much longer video:

Two anoles, the ubiquitous Jamaican (Graham’s, Anolis grahami), which adorns every wall in Bermuda, and the seldom seen Barbados (A. extremus), just an occasional shadow in the shade, somehow finding themselves on the desirable territory of my bedroom window. They never came to blows, but the latter was definitely the winner, the Jamaican eventually retreating with his tail between his legs (metaphorically) after 8 minutes of posturing.

For more on the introduced anoles of Bermuda, see previous AA posts (here and here).

Photo by Wendy Frith

I live in Bermuda.

Many years ago, my daughter and I witnessed a large male Graham’s anole devour a small female, same species. We were horrified as we had watched these particular individuals so often we’d named them…the male was Pat Rafter as he spent much of his time up by the porch ceiling light catching bugs there; the victim was Porsche, because she was always on the porch wall railing. 

One day, I heard a scream from the porch…not from the lizard, but from my daughter: “Pat is eating Porsche!” and I arrived in time to see him sitting in her favorite spot with her back-half still protruding from his mouth. After the final gulp, he sat basking in the sun for a long time, then waddled off leaving an extra-long turd behind. My daughter and I went over and addressed it, with many apologies. We hadn’t known he was not just merely blue (and turquoise and purple) but was a reptilian Bluebeard…in fact, even worse: a Cannibal Bluebeard!

On the other side of the house there was a male I named Brown (because a friend of mine had a brown dog he’d named Purple). I taught him to accept food from my finger, and to come to the bathroom window when I whistled Bach’s Brandenburg Concerto #3 in G. He’s the one pictured at the top and bottom of this post.

Drawing by Wendy Frith.

Anolis winstoni from https://commons.wikimedia.org/wiki/File:Anolis_oculatus_at_Coulibistrie-b01.jpg

Peter Mudde writes:

I am chairman  of Lacerta, the Dutch Herpetological society. I also am a regular contributor to the magazine Lacerta. Lacerta  recently made an “Anolis special.” We are preparing a printed English version and we have an internal discussion about the matter below. 

In 1962 the late Skip Lazell, a regular contributor to Anole Annals described Anolis oculatus winstoni, stating: “This subspecies is named for Charles A. Winston, Manager of Woodford Hill Estate, and his family.” In recent years, the epithet “winstoni” has been changed to “winstonorum” as that would be he proper grammatical form if the subspecies was indeed named after Winston and his family (Michels and Bauer, 2004). This was critisized by Dubois (2007).

Now I am not familiar with the latest in zoological taxonomy, but I was under the impression that a name once given could not be corrected afterwards. That’s why the American alligator still misses a character in it’s scientific name.

Indeed, the combination Anolis occulatus winstonorum has emerged several times, mainly in non-scientific literature. Now my question is: how do those working with anole taxonomy refer to this subspecies?  Your verdicts please.

From the pages of The Straits Times:

NParks monitoring whether brown anole, greenhouse frog pose threat to native species

SINGAPORE – In many areas across Singapore, one may find small, slender lizards – sometimes displaying a yellow or reddish orange flap under their throats – if one looks intently enough.

These lizards, which can be found on the ground or trees, are called brown anoles (Anolis sagrei), and they have been spotted at an increasing frequency across the island.

The catch is: They are not supposed to be here.

The brown anole is found naturally in the Bahamas, Cuba and the Swan Islands.

It is one of two introduced species – the other being the greenhouse frog (Eleutherodactylus planirostris) – that have been seen here more often, and in more places.

The greenhouse frog is native to the Bahamas, Cuba and the Cayman Islands.

In March, two brown anoles were spotted on the balcony of a residential unit in Sembawang.

Introduced species are plants or animals that are not naturally found in Singapore.

They can be considered invasive when their presence causes harmful impacts on the local environment. This could happen if, for instance, they outcompete native species due to a lack of natural predators, high reproductive rates and adaptability to different environmental conditions.

The National Parks Board (NParks) told The Straits Times that it is aware of the presence of the brown anole and greenhouse frog in Singapore, and that it is monitoring the situation.

Dr Karenne Tun, group director for NParks’ National Biodiversity Centre, said the brown anole has outcompeted the native green anole in the US state of Florida, and in Taiwan it has impacted local arthropod – invertebrate animals with an exoskeleton – communities in betelnut palm plantations. In Hawaii and other parts of the US, the greenhouse frog has also been documented as invasive, she added.

However, there is no evidence that these species have significantly impacted local ecosystems so far, said Dr Tun.

Observers believe the two Caribbean species came into Singapore by “piggybacking” on exotic plants that were brought in by the horticultural sector.

Dr Alex Figueroa, executive secretary of the International Commission on Zoological Nomenclature based at Lee Kong Chian Natural History Museum at NUS, said brown anoles continue to be introduced throughout the island, via plants imported by nurseries.

“At this moment, brown anoles do not appear to be invasive in Singapore,” said the reptile and amphibian researcher.

He said that most of the lizards found here are bigger than the brown anole – which is usually about 12cm to 21cm long – and either live on the ground or high in the trees. Meanwhile, brown anoles prefer warm, open grassy areas and the lower parts of trees and shrubs.

According to a report by Nature in Singapore, an online journal of the Lee Kong Chian Natural History Museum, brown anoles were observed and recorded in Singapore for the first time in 2012, when they were sighted at Gardens by the Bay.

“The many individuals, hatchlings and courtship activities observed at the Gardens by the Bay strongly suggest that the brown anole has already established a population in Singapore, at least within Marina Bay,” said the report, adding that it is the first reptile from the Americas that has done so there.

Years later, they continue to be spotted in different parts of the island, such as in Bishan in 2015, Jurong Lake Gardens in 2020 and Chua Chu Kang in 2022.

When The Straits Times visited Gardens by the Bay in March, a brown anole was spotted perched on a tree trunk near the Bayfront MRT station. Subsequently, 11 more were spotted in less than 1½ hours.

As for the greenhouse frog, the first sighting of the small amphibian – its length ranges from about 12mm to 30mm – was recorded in Sembawang in 2015. These creatures were also spotted in Clementi Woods and Dairy Farm Nature Park in 2017.

While a population study has yet to be done on the greenhouse frog in Singapore, Mr Robbin Tan, a scientific officer at the Herpetological Society of Singapore (HSS), said: “Today, the greenhouse frog is widespread across Singapore, including within our Central Catchment Nature Reserve… We can ascertain that there are plenty of breeding populations established in Singapore.”

Mr Tan said the greenhouse frog has successfully established populations throughout Hawaii, Hong Kong and the Philippines. Its global spread has been primarily driven by the plant trade, he added.

Dr Figueroa said that while it is hard to estimate their population without properly studying the frog, it is “safe to say” that they can be found throughout Singapore, and in some areas, they can be found in large numbers, although this is difficult to tell given how tiny they are.

While the frog can be found widely across the island, it remains to be seen if they are harmful to the native species due to lack of evidence, experts said.

However, Associate Professor Darren Yeo, head of the Lee Kong Chian Natural History Museum at NUS, said they may be considered potentially invasive, as they are already widespread in Singapore, and can spread rapidly.

Greenhouse frogs skip the tadpole stage entirely, and their eggs develop into frogs. This also means that, unlike other frogs, they do not need water bodies to breed, which enhances their ability to spread, he said.

HSS’ Mr Tan added that due to its small size, habitat and diet, the greenhouse frog may also compete with native chorus frog species, especially since both can be found in similar places, like secondary forests and leaf litter.

Ms Tricia Cho, a research assistant at Lee Kong Chian Natural History Museum at NUS, who has done research on greenhouse frogs, said more research and monitoring could be done to assess their population status and quantify any negative effects they might bring to the local ecosystem.

HSS’ Mr Tan said that public education campaigns and citizen science programmes encourage people to report sightings, avoid releasing non-native pets, and support conservation efforts.

Besides regular monitoring and early detection, he said that restoring native habitats and reducing human disturbances strengthen ecosystem resilience, making it harder for non-native and invasive species to establish.

Prof Yeo said that most invasive and non-native species in Singapore tend to be found in more urban or artificial habitat areas and less in more forested and natural habitat areas.

“This could reflect a preference for urban or artificial systems or a resistance by the native communities in natural systems,” he said. “If it’s the latter, we can help prevent invasive species from affecting the ecosystems by keeping as much of the ecosystems and their faunal and floral communities as intact as possible.”

• Chin Hui Shan is a journalist covering the environment beat at The Straits Times.

Anolis carolinensis (Green Anole) in the City of Norfolk (photo by Zachary Steele).

Growing up in Florida, I was used to seeing Green Anoles, so when I moved to Virginia to start my PhD at Old Dominion University, I wasn’t surprised to see Green Anoles venturing around Norfolk. If anything, seeing the familiar anoles for the first time in the Summer of 2021 gave me a warm feeling of home. However, several months later, I began to realize that I was only seeing these anoles in one specific location. When my friends and colleagues (such as my coauthors Antonella Panebianco and Karen Caceres) would join me on trips to a nearby public beach, we’d always see the anoles as we parked and made our way to the beach, but we never saw the anoles anywhere else. At this point, I began to realize that I’d never really looked closely at the native range of the Green Anole; I knew it extended into North Carolina, and I assumed Virginia as well based off our sightings, but I had never confirmed this. As a result, one day, after returning home from this beach, I found myself researching the native range of the Green Anole…and was shocked to uncover that the anole was not native to Virginia. Instead, I learned that while the anole population had been spreading north towards the North Carolina-Virginia border (although it’s unclear whether this was natural or expansion through introductions) over the last 60 years, the range had not yet expanded into Virginia. I also quickly determined that there was another non-native population of these anoles in Virginia Beach, roughly 20 miles east of the population that we had located.

After gathering this information, we began to put more effort into documenting this population via iNaturalist. This led to us realizing that the extent of this anole population (~ 35 acres) was larger than we previously perceived, and we also observed juvenile anoles which revealed that this was likely a breeding population. Additionally, through these efforts, we also realized other users had reported anoles from this introduced population on iNaturalist, with reports dating back to 2019. All this evidence suggested that this anole population had likely endured several winters and indicated that this was an established non-native population. While Norfolk can have some relatively harsh winters, these winters aren’t very different from the northernmost native range of the anole in Tennessee and North Carolina. Our observations also indicated that there wasn’t much potential for predation and competition for these introduced anoles, which suggested that this population has the potential to continue to grow.

Through this process, what we gathered was that it’s always a good idea to confirm the extent of a species’ native range. Documenting both natural range expansion and range expansion through human introductions is critical, and anyone can contribute to these efforts using platforms like iNaturalist and EDDMapS. Quickly uploading an observation to these types of platforms can really benefit the research community!

Check out the publication in Northeastern Naturalist for more information!

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