Color in life of Anolis laevis. Dewlap of adult male (A), lateral head of adult male (B), lateral body of adult male (C), ventral body of adult male (D), lateral head of adult male stressed (E), lateral body of adult male stressed (F), mouth of adult male (G), dewlap of adult female (H), lateral body of adult female (I), ventral body of adult female (J), lateral head of adult female stressed (K), lateral body of adult female stressed (L).

The rediscovery of Anolis laevis is one of those stories that seem written to remind us why biological exploration remains indispensable. Described in 1876 from a single specimen, holotype ANSP 11368, and then lost to science for a century and a half, this small anole with a strange proboscis on its snout became a myth of the montane forests of northeastern Peru. For more than a decade, herpetologist Pablo Venegas conducted repeated and systematic surveys throughout the region, from 2003 to 2018, intensively searching the same montane forests without finding a single trace of the elusive Swordsman anole, reinforcing its reputation as a species that might have vanished forever.

Holotype of Anolis laevis ANSP 11368 (SVL = 60.0 mm). Head in dorsal (A), lateral (B), and ventral (C) views. Body in dorsal (D), and ventral (E) views. Tail in ventral (F) view.

The work reported in our recent paper began quietly in 2008, when two adult females were collected in Laguna Negra, in the department of San Martín, Peru, without anyone knowing at the time that they held the key to solving a historical enigma. Ten years later, in 2018, two adult males appeared in Posic and Nuevo Chirimoto, confirming that the “swordsman anole” was still alive. It was at that moment that a systematic investigation began which, after years of comparing morphology, reviewing historical collections, and documenting living individuals, succeeded in bringing to light a species that had remained in the shadows for generations.

The process was as captivating as it was rigorous. Researchers compared every detail of the new specimens with the 19th-century holotype, a specimen that is deteriorated but still retains the diagnostic characteristics that define the species. The male’s small rostral proboscis and dorsal crest formed by triangular scales are still visible, features that match precisely with the rediscovered animals, dispelling fears that this was a different cryptic species. The study also revealed a surprising sexual dimorphism: the females, unknown until now, completely lack a proboscis but have a black gular fold with white scales, while the males have a pink gular fold with a bluish border. This revelation not only completed the portrait of A. laevis, but also provided an essential piece of the puzzle for understanding how sexual selection and visual signaling operate in these Andean anoles.

Sexual dimorphism in Anolis laevis.

The work condenses decades of uncertainty into a powerful visual sequence. The holotype allows us to observe, from dorsal, lateral, and ventral views, that even after 150 years of preservation, the key features are still there, anchoring the species’ identity to the present. The photographs reveal a lichen-colored lizard, almost camouflaged among moss and damp leaves, and show the female with her dark dewlap deployed for the first time. Comparison with other proboscis anoles, such as A. phyllorhinus from Brazil and A. proboscis from Ecuador, highlights a fascinating evolutionary truth: although these “big-nosed” lizards look alike, they belong to different lineages.

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Figure 1: A) Trunk-dwelling Cyrtodactylus consobrinus © L. Grismer. Its subdigital scales (the scales below the digits, where toepads might evolve) are covered with spines (inserted). B) Crown-dwelling C. elok © L. Grismer. Its subdigital scales are covered with setae (inserted). Both of these species have incipiently expressed toepads (lamella-like scales), although these are more strongly expressed in C. elok than in C. consobrinus (Riedel et al. 2024). Microstructure images from Ginal et al. 2026.

Like anoles, geckos are famous for their adhesive toepads, enabling astonishing climbing abilities. Since adhesive toepads evolved independently in geckos and anoles, these two rather distantly related lizard clades have become the poster-children of convergent evolution in climbing. But, astonishingly, how such a complex system actually evolves has until recently garnered little attention. And while anoles have long been celebrated for their sticky pads, the literature tends to treat the spectacular adhesive system in a binary fashion as either being present (full pads) or absent (pad‑less) in geckos– despite the fact that earlier research already indicated that this might not be the case.

The genus Cyrtodactylus (~ 400 species) is an excellent vehicle for studying the transition from a pad‑less ancestor to a fully adhesive foot because its members occupy a dizzying array of habitats — from ground‑dwelling leaf‑litter specialists to tree‑crown acrobats — quite comparable to Anolis lizards in this regard. And not only that, but our previous work has revealed that Cyrtodactylus displays a continuum of sub‑digital scale shapes ranging from tiny round scales to broadened, lamella‑like “incipient toepads” (Riedel et al. 2024).

So, building on these previous studies, we embarked on a project to look at the sub-digital microstructures of Cyrtodactylus geckos as the logical next step. The dry‑adhesive systems of geckos and anoles rely on arrays of microscopic filaments called setae (Fig. 2). In geckos four filament types have been described (Garner & Russell 2021): spinules, spines, prongs, and setae (Fig. 2). While spines ancestrally cover most parts of the skin of geckos and anoles alike, and likely evolved for self-cleaning purposes (lotus effect), spines and prongs have been hypothesized to be “pre‑adhesive” adaptations that improve traction on rough surfaces. Only setae have been proven to generate sufficient van‑der‑Waals forces capable of generating adhesive forces of sufficient magnitude to support the entire animal.

Figure 2: Microstructures found in geckos and anoles. Spinules are short, tapered filaments covering the majority of the skin of geckos and anoles alike. Spines are somewhat longer with pointier tips, while prongs have blunt, flattened tips. Setae are long filaments possessing triangular tips, called spatulae. Illustration from Ginal et al. 2026 (redrawn and modified from Garner & Russell 2021).

The actual study, building upon a hypothesis formulated 50 years ago (Russell, 1976), began with checking museum specimens for the presence of subdigital microstructures using light microscopy, since the outer skin layer is often lost in specimens stored in ethanol for long time periods. Of the 86 specimens examined, spanning 30 species from four museum collections, 53 specimens belonging to 27 species were suitable for examination with the scanning electron microscope (SEM), which is the standard tool for studying integumentary microstructures in reptiles. Although representing only a small fraction of the 400 species of Cyrtodactylus, this sample constituted a sufficiently broad phylogenetic coverage across the genus. It also incorporated representative stages in the sub-digital scale shape continuum and species representing multiple habitat preferences (ecotypes). SEM imaging was used to first categorize microstructures into the four known types (Fig. 2) and then to quantify various parameters, such as filament length, diameter, and density, which are known to vary across species and microstructure types, all of which are related to the function of these structures. From these measurements, effective bending stiffness – a measurement of flexibility, which is particularly important for setal function – could be calculated. We then applied different modelling approaches to test for correlations of both microstructure types and measurements with ecotypes and reconstructed their evolutionary history to compare their evolution with the evolution of scale shapes as reconstructed in our previous study.

We found that spines are likely the ancestral condition for the genus at large and that prongs evolved three times independently from spines, while setae evolved two times – once in the intertidal species C. seribuatensis and once in a large crown group including many but not all arboreal or saxicoline (rock-dwelling) lineages (Fig. 3). This indicates that microstructure types are phylogenetically constrained. Interestingly, the two arboreal clades with strongly expressed incipient toepads (lamella-like subdigital scales) are nested within the setae-bearing crown group, indicating that the evolution of setae preceded the evolution of lamella-like scales in these lineages. Thus, our results suggest that adhesive competence may arise before the classic “lamella” morphology. However, C. consobrinus (a trunk species) shows the incipient toe pad gross morphology of its subdigital scales but lacks setae—its microstructures are spines, indicating the converse may also be the case.

Figure 3: Ancestral state reconstruction of the microstructure types of our sample of Cyrtodactylus geckos. * & ** indicate weak and strong transitions towards incipient toepads (lamella-like scales) reconstructed by Riedel et al. (2024). SEM images of microstructures and subdigital scale shapes are illustrated for some species. (Ginal et al. 2026)

The ecotype (e.g., cave, crown, granite, karst) of a species does not predict whether a species has spines, prongs, or setae. However, specific filament traits (e.g., apical diameter, effective bending stiffness) differ significantly among ecotypes—crown‑dwelling species have the smallest apical diameters and the most flexible filaments (lowest effective bending stiffness). Thus, it appears that phylogeny determines what filament type a species has, while micro‑habitat fine‑tunes how those filaments are built.

Overall, our study provides important insight into the evolution of toepads, in that we show that setae (indicative of adhesive competency) can evolve without the expression of obvious macro‑scale pads, and that multiple independent origins of setae have occurred within a single genus. These findings highlight the evolvability of the adhesive system and establishes that the genus Cyrtodactylus offers a living laboratory for the study of the stepwise evolution of complex adhesive systems (thus providing an excellent platform for comparative studies with anoles and other climbing squamates).

If you want to read more, check out our open-access paper:

Ginal, P., Y. Ecker, T. Higham, L. L. Grismer, B. Wipfler, D. Rödder, A. P. Russell, & J. Riedel (2026): Subdigital integumentary microstructure in Cyrtodactylus (Squamata: Gekkota): do those lineages with incipiently expressed toepads exclusively exhibit adhesive setae? Beilstein Journal of Nanotechnology 17: 38–56. https://doi.org/10.3762/bjnano.17.4

Further references:

Riedel, J., K. Eisle, M. Gabelaia, T. Higham, J. Wu, Q. H. Do, T. Q. Nguyen, C. G. Meneses, R. Brown, T. Ziegler, L. L. Grismer, A. P. Russell, & D. Rödder. 2024: Ecologically-related variation of digit morphology in Cyrtodactylus (Gekkota, Squamata) reveals repeated origins of incipient adhesive toepads. Functional Ecology 38: 1630–1648. https://doi.org/10.1111/1365-2435.14597

Garner, A.M. & A.P. Russell, 2021: Revisiting the classification of squamate adhesive setae: historical, morphological and functional perspectives. Royal Society Open Science 8, 202039. https://doi.org/10.1098/rsos.202039

Russel, A. P. (1976): Some comments concerning interrelationships amongst gekkonine geckos. In: D’Bellairs, A., Cox, C. (Eds.), Morphology and Biology of Reptiles. Academic Press, London, pp. 217–244.

Photo by Miriam Lipsky

Happy ending: they both lived to see another day thanks to the screen between them! Thanks to Miriam Lipsky for the photo from Miami.

JUST PUBLISHED: Understanding Animal Behaviour is a non-fiction graphic novel featuring anoles and other lizards. This isn’t a kid’s book or comic. It is written for adult readers interested in understanding why animals do what they do and how researchers go about studying behaviour.

And its FREE.

Here’s a taster from Chapter 4 on the challenges anoles face when trying to advertise territory ownership in natural environments.

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Ok, not actually breaking news–occurred almost eight years ago, but somehow word never reached Anole Annals. People magazine tells the story:

 

Nearly three years after taking over The Late Show from David Letterman, Stephen Colbert finally welcomed the first animal expert back on the CBS program, Friday. But… he might regret that decision.

The 53-year-old talk show host sat down with Nathaniel “Coyote” Peterson, the animal expert and adventurer known for his popular YouTube show Brave Wilderness — for which he travels the globe letting animals and insects bite and sting him.

It was only fitting, then, that Peterson brought an animal along to bite Colbert. “I was told you wanted to enter the bite zone,” Peterson said, before pulling out the green anole lizard. “What we have here is…arguably one of the most painful lizards in the world. They can be found all throughout Florida and maybe even here in New York because they often times escape as people’s pets.”

He then asked Colbert, “If you’re brave enough, and I know you are, you’re actually going to be bitten by one of these anoles.”

Colbert was game, though he was nervous. “I wanted to do something that wasn’t very painful,” he said. “Lizards don’t really bother me but is it going to hurt?”

“That’s yet to be determined,” Peterson said. “How are you going to endure the pain. It’s all on you. You have to mentally prepare yourself. When I do this and I’m bit and stung by things, I kind of walk and pace behind the cameras before I actually go through with it.”

The former Colbert Report host didn’t do that. Instead, he stayed seated — looking directly into the camera before saying, “I’m Stephen Colbert and I’m about to enter the bite zone with the green anole.”

That’s when Peterson put the lizard up to Colbert’s ear — because “the ear is the best place to be bit by this thing, then it just kind of hangs there like an earring,” according to Peterson.

As for the bite, Colbert handled it well. “Well done. Well done,” Peterson said.

Tulane University reports:

Study: Invasive lizards’ tempers flare with the heat

from the pages of Rhody Today:

KINGSTON, R.I. – Dec. 11, 2025 – How do intermittent events like hurricanes impact natural selection? How do animals adapt to challenging weather? A University of Rhode Island professor has set out to track natural selection in the Anolis lizard over time to see how the species has weathered hurricanes in the southeastern United States.

A new paper by Jason Kolbe and colleagues published in the Proceedings of the National Academy of Sciences finds hurricane-induced selection and responses to hurricanes in Anolis lizards. Chair of URI’s Department of Biological Sciences, Kolbe studies how human-mediated global change phenomena drive evolutionary change in the natural world.

If species’ mortality depends on specific traits, then hurricanes — extreme and intermittent in nature — provide a source of episodic natural selection on affected populations. The predicted increase in hurricane activity and strength in the North Atlantic has the potential to alter patterns of selection and evolution for populations, especially in coastal areas and islands.

The paper’s focus brought Kolbe back to the start of his professional research career. He has studied lizards for 25 years and used genetic markers to reconstruct the invasion histories of Anolis lizards introduced to Florida from the Caribbean for his dissertation.

As part of his Ph.D. research, Kolbe studied the ecology and evolution of anole populations on islands in the Bahamas. When Hurricane Sandy hit their study site there in 2012, he decided to use the devastating storm’s impact to compare lizards before and after impact.

The invasion of Anolis sagrei in the southeastern U.S. provided a rare opportunity to put a timestamp on the start of adaptive evolution for populations in this region, Kolbe says. Over 100 hurricanes have hit Florida since the start of the A. sagrei invasion.

Their results affirmed that hurricanes are a source of episodic selection with lasting evolutionary effects on lizard traits connected to weathering storms. Kolbe’s team’s preliminary analysis found lizards with longer limbs survived better during the hurricane and that lizards with longer limbs possessed greater clinging ability, supporting hurricanes as a source of natural selection for lizard populations.

“Our studies of the brown anole in Florida provided an excellent opportunity to test whether hurricane-induced selection could shape the morphology of lizards over the course of their invasion, around 100 years,” he says. “Because we have a good estimate of the time each brown anole population in our study was established and hurricane records go back to 1851, we were able to estimate the number of hurricanes impacting each population and test for an association with traits that increase clinging performance.”

Introduced lizard

The Anolis sagrei was introduced in Florida and Georgia beginning in 1887 in the Florida Keys. It showed up on the peninsula a half-century later. Kolbe’s team reconstructed a chronology of the A. sagrei invasion in Florida and Georgia using dates from published observations and museum specimen records.

Brown anoles were introduced to the U.S. from at least eight geographically and genetically distinct source populations in their native range, mostly from Cuba. These introductions likely occurred accidentally via shipping or intentional introductions (release of pets into the wild).

Kolbe and his colleagues found that brown anole populations experiencing more hurricanes had longer limbs and larger toepads, traits that help them hold on — both in the immediate sense of a single storm and in the long-term as well, in terms of natural selection. Their results confirm hurricanes as a major force shaping variation in Anolis lizards and highlight how the evolutionary trajectories of animal populations will be altered as climate change modifies historical patterns of natural selection, he says.

An evolutionary ecologist, Kolbe studies the evolutionary response of species adapting to rapid environmental shifts and says that biological invasions are useful scenarios to study rapid evolution.

Although there aren’t many good studies on the ecological impacts of this species, its high densities, rapid spread and generalist nature suggest potential impacts on other species, Kolbe says, noting that other species could be studied, as well.

“Lizards are surely not the only species potentially experiencing selection during hurricanes,” says Kolbe. “Our understanding of episodic selection may be enhanced by studies on the evolutionary effects of hurricanes on other species, not only lizards.”

Figure 1. The skin colors of the Anolis carolinensis. (A) Brown; (B) Green.

We’ve long known that some lizards change color for camouflage or communication, but our new research reveals their skin may also act as a dynamic thermal regulator. Our study published in Animals explores how the green anole (Anolis carolinensis) adjusts its skin color and reflectance in response to short-term temperature changes, offering fresh insights into how ectotherms adapt to their environment.

Figure 2. Skin color changes in the same Anolis carolinensis individual under different ambient temperatures. (A) 20 °C; (B) 30 °C; (C) 40 °C; (D) 24-color checkerboard.

Using controlled lab experiments, we exposed lizards to temperatures ranging from 20°C to 40°C against white and brown backgrounds. We tracked changes in skin color, body temperature, and spectral reflectance. Key discoveries include:

1. Brighter at higher temps: As ambient temperature increased, the lizards’ skin became brighter and less chromatic, shifting from dark green to light green.
2. Optimal at 30°C: At this temperature, the lizards’ body temperature closely matched their environment, suggesting a thermal preference.
3. Reflectance shifts: Skin reflectance in both visible and near-infrared light increased with temperature, indicating a role in managing heat absorption.

This study shows that color change in A. carolinensis is not just for hiding or social signaling. It is also a dynamic form of thermoregulation. In cooler conditions, darker skin likely helps absorb more heat. In warmer conditions, lighter, more reflective skin may help prevent overheating. This ability may be especially important for ectotherms (cold-blooded animals) that rely on external sources to manage their body temperature. As climate change reshapes habitats worldwide, understanding these adaptive strategies could be key to conserving ectotherm populations.

Figure 3. Schematic illustration of Anolis carolinensis skin color and body temperature responses to different ambient temperatures.

Reference:

Hu, J.; Xiong, Y.; Liu, R.; Chen, X.; Liang, A.-P. Skin coloration changes and thermoregulation in Anolis carolinensis across different thermal environments. Animals 2026, 16, 203. https://doi.org/10.3390/ani16020203

Figure 1. Sleeping green anoles on leaves (Photographs by Osamu Sakai).

Sleep is one of the most fundamental states for animals, including humans and wildlife. When people travel to unfamiliar places, one of their first concerns is often where they will sleep that night — at least it is for me. Lizards may face a similar challenge.

Like other diurnal Anolis lizard species, green anoles (Anolis carolinensis) are active during the day and rest at night. Sleeping on vegetation is thought to be a common strategy among arboreal anoles, likely reducing the risk of attacks from ground-dwelling predators. But, how do they sleep in the wild when living in an unfamiliar, non-native environment? Which plant species do they use for beds? Do males and females differ in their choices, or do sleeping habits change across life stages? To address these questions, we investigated the night-time microhabitat use of free-ranging green anoles.

Our focal population is A. carolinensis on the Ogasawara Islands, Japan, located about 1,000 km south of Tokyo. This population originated in North America (the Gulf/Atlantic clade) and has been established on these subtropical islands since the 1960s. During night-time surveys, we observed the green anoles perched on leaves with their eyes closed (Fig. 1). They showed no reaction to flashlight illumination and only a weak response, if any, to gentle tactile stimulation. In short, they appeared to be fast asleep!!

Our survey revealed no sexual differences in sleeping sites with respect to perch height (Mean: males = 256.2 cm; females = 261.7 cm) or the plant species used for beds. In contrast, juveniles slept on much lower vegetation (Mean = 103.0 cm) and used different plant species to adults (Fig. 2).

Figure 2. Ontogenetic niche shifts in the sleeping sites of green anoles. Adults and juveniles used different beds in terms of perch height and variety of plant species. The similarity of the plant species was assessed using Pianka’s niche overlap index

We also found that the characteristics of their sleeping sites were influenced by habitat type. Comparisons between natural forests and human-modified areas suggest that local vegetation has a strong influence on the types of leaves that the green anoles sleep on (Fig. 3). In human-modified habitats, the green anoles were frequently found sleeping on two palm species: the Formosa palm and the golden cane palm. However, at natural forest sites where these palms are absent, the green anoles did NOT rely on particular plant species for their beds.

Figure 3. Comparison of the plant species used by adult lizards in (a) natural vegetation (n = 25) and (b) human-modified environment (n = 98). An asterisk (*) after the plant name represents non-native species on the Ogasawara Islands.

Together, our findings provide a natural history note on A. carolinensis. Notably, the green anoles exhibit an ontogenetic niche shift in sleeping site: as they grow, they change both the perch height of the plants and the species they use for sleeping. Is this niche shift also observed in native green anole populations? Does this pattern have adaptive significance? Further research would be valuable in answering these questions.

Finally, we’d like to discuss the implications for invasion biology. On the Ogasawara Islands, the introduced A. carolinensis has caused severe declines in the native insect fauna, including many endemic species. Improving our understanding of the basic natural history of these animals (i.e., sleep ecology) could contribute to more effective management and control. If you’d like to learn more, the full open-access paper is available in Herpetological Conservation and Biology 20(3): 519–527.