All posts by Jonathan Losos

About Jonathan Losos

Professor and Curator of Herpetology at the Museum of Comparative Zoology at Harvard University. I've spent my entire professional career studying anoles and have discovered that the more I learn about anoles, the more I realize I don't know.

Which Anole Is That in the Addams Family Dollhouse?


anole skeletonJoe Martinez of the Museum of Comparative Zoology writes in: “I was recently contacted by Samantha Grantham, the collections manager of the Wenham Museum in Wenham Massachusetts, who would appreciate learning the identification of a lizard skeleton that resides in the Coffin Room of their Addams Family dollhouse. The dollhouse was constructed locally, presumably with artifacts that were readily available.

It appears to be an anole and Anolis carolinensis would have been available through the pet trade at that time. Anolis sagrei may have begun showing up in the pet trade as well by then. Can anyone give an authoritative identification?”

And want to learn more about the Addams Family Dollhouse? There’s a whole blog devoted to it!


New Book on the Anoles of Honduras


johnsmeyersiMcCranie and Köhler have just published an authoritative account of the 39 species of Honduran anoles. Rich in detail and thorough in coverage, this volume will be of interest to anyone interested in neotropical herpetology.

Harvard University Press’s description says it all: Caribbean members of this group have been intensively studied and have become a model system for the study of ecology, evolution, and biogeography, but knowledge of the anoles of Central and South America has lagged behind. In this landmark volume, veteran herpetologists James R. McCranie and Gunther Köhler take a step toward rectifying this shortcoming by providing a detailed account of the rich anole fauna of Honduras. Generously illustrated with 157 photos and drawings, The Anoles of Honduras includes information on the evolutionary relationships, natural history, distribution, and conservation of all 39 Honduran anole species. The work is the result of decades of study both in the field and in museums and is the first synthetic discussion of the complete anole fauna of any Central or South American country. Each species is described in great detail with locality maps. Bilingual (English and Spanish), extensively illustrated identification keys are also included.

Distribution maps are provided for all species.

Distribution maps are provided for all species.

Like all publications of the Bulletin of the MCZ and Breviora, the book is freely available as a pdf on the journal’s website. But a pdf just doesn’t look right on a bookshelf, not to mention getting soggy in the field. For those who really  want to get the most out of this volume, why not consider purchasing it from Harvard University Press for only $24.95 (not bad for a 280 page volume jam-packed with color photos!)? And it’s even cheaper on Amazon (currently $20.48).


Help Identify Anole from Guyana

Photo by Thadaigh Baggallay

Thadaigh Baggallay writes: “I took this picture in Kaieteur National Park, Guyana. Anolis chrysolepis perhaps?”

Looks to me like whichever chrysolepis-type anole occurs in Guyana. Exactly a year ago today, we had a post on a new field guide to Guyanan herps by Cole et al. which probably would help. According to that guide, I believe the species would be A. planiceps. Any thoughts any one?


Video of Anolis pentaprion Displaying

Little is known about the Central American twig anole, but it does have a beautiful dewlap! In recent years, what used to be known as A. pentaprion has been split into a large number of species, the most recently described of which is A. triumphalis. (Editor’s note: Gunther Kohler points out that this is one of the newly named species, A. charlesmyersi).

Here’s the backstory from the videographer who posted this on Youtube: Greetings Casa Alta Vista, Costa Rica. That video was shot about 15 feet above ground, on the guava wood handrail that goes up my stairs. Our house is a rustic style “pole” house, constructed from plantation grown gmelina and teak woods. We are located about 2 miles inland of the shores of Golfo Dulce , Costa Rica, at about 600 feet elev. in a mostly second growth seasonally dry rainforest. Dry season from Dec to April, then usually 300 inches of rain , a lot of which is in September-October usually. We are across the gulf from Corcovado National Park . Maybe 15 miles as the toucan flies. The area around the house was pasture up until about 20 years ago, but now pretty lush with second growth. Fairly undeveloped, and there is some primary growth surrounding us down in the “quebradas” or streams that are all around here. Down there we have stream anoles, and lots of snakes and critters. Saw a bushmaster down there once . Yikes. We also see slender anoles (I think) but they aren’t very “brown” and the yellow spot on the dewlap isn’t as prominent as the picture in my book . We also sometimes see the dry forest anole, which seems to trade off the territory of my deck railing system with the lichen anoles. We see green anoles down on some of the fruit trees we have planted as well. Amazing creatures all, they don’t seem fearful of us, and maintain eye contact . And will bite of course if they are provoked and can catch hold of you. I once had a full grown basilisk lizard that I was rescuing from some dogs bite me nicely on the hand. We have really a lot of all kinds of wildlife here. The birding is great, and we have a large troop of mono titi’s (squirrel monkeys) that occasionally traverse our back deck, peek in the windows, and move on to eat guabo beans in the trees surrounding our house. We’re built about 4 meters off the ground, not a treehouse , but kind of up in the trees .
My camera is new, and I will be posting other animal videos soon. And will try to get more anole videos.

Editor’s Update, 2/23/2015:

Here’s another clip of the same animal:

Geographic Variation in the Mainland Grass Anole Anolis auratus

Photo by James Christensen

Anolis auratus is one of the most widespread mainland anoles, with a range stretching from Costa Rica through much of northern top of South America on both sides of the Andes. It’s biology is surprisingly little known, though it is thought to be a grassland species; that and it’s morphological similarity to grass-inhabiting Caribbean anoles has led some to argue that this species is a member of the grass-bush ecomorph category.

Given it’s wide range in Colombia traversing the Andes, the species is ripe for investigation of geographic variation, and that is just what Martha Calderón-Espinosa and Leidy Alejandra Barragán-Contreras did, examining a large number of museum specimens in the collection of the Instituto de Ciencias Naturales, Universidad Nacional de Colombia. Their work was recently published in Acta Biológica Colombiana. The abstract is appended below, but to make a not-so-long story short, sexual dimorphism exists for several characteristics independent of body size (the sexes don’t vary in size), and these same characters vary geographically. What this means about variation in habitat use of the species across its range remains to be studied.


Anolis auratus is a widely distributed species, from Costa Rica in Central America, through northern South America, including Colombia, Venezuela, northern Brazil, Surinam and the Guyanas. In Colombia, its widespread distribution across different life zones suggests that these lizards occupy different environments and exhibit different microhabitat use in different geographic areas. On the other hand, some observations suggest that this species prefers open areas, selecting grasslands over brushy areas, and thus, an alternative hypothesis is that microhabitat use is similar among different populations. In Anolis, body variables related to locomotion (body size and shape) define structural microhabitat use, so two distinct patterns could be expected in this species: conservative or highly variable body size and shape throughout the species distribution. To test these predictions, we characterized geographic variation in morphometric traits of this species in Colombia. Females and males were similar in body size, but exhibited differences in some variables related to body shape. These characteristics also varied among males and females from different regions, suggesting heterogeneous use of structural microhabitat, between sexes and among populations. As an alternative, phylogenetic divergence among populations could also account for the observed differences. Absence of ecological and phylogenetic data limits our ability to identify the underlying causes of this pattern. However, we provide a general framework to explore hypotheses about evolution of body size and shape in this species.

Mating and Egg-Laying Behavior of Anolis smallwoodi

copulating smallwoodi

Despite the intense study of all things anoles for several decades, some aspects of their natural history are not all that well known. For example, the mating behavior of most species has not been described, and egg-laying behavior has been documented for only a few species.

In the most recent issue of IRCF Amphibians & Reptiles, Alfonso et al. take a small step to remedy this situation by describing these behaviors in the Cuban crown-giant anole, A. smallwoodi. The mating observations are from a year’s fieldwork by the senior author, whereas the observations of egg-laying are from the captive husbandry efforts of second author Veronika Holanova.

I was particularly interested in the description of how gravid females come down to the ground and poke around with their snouts until they find just the right spot, at which point they dig a hole with their snout, lay the egg, and then cover it up by pushing soil over it with their snout and forelegs.

Knight Anole Vs. Red Rat Snake: Who Will Win?

equestris being eaten by a snakex

The picture above comes from a post on Jacqui Thurlow-Lippisch’s blog, about an epic battle in Sewall, Florida. Jacqui kindly put me in touch with the photographer, Nina Barcik, who provided some more information:

  • The two bricks beneath the snake are:  4½”x 6″ and   6″x 9½” to give you some reference for size.
  • One hour and 20 minutes after the picture was taken, the lizard was completely consumed and the snake was on it’s back with the head and first 6″ leaning vertically against the side of the planter.

30 minutes later the snake was gone.

By the way, who prefers the name corn snake to red rat snake?

Here’s another shot:

equestris being eaten by a snake2x

Anole Wallets and Pillowcases Now on Sale

Nearly two years ago, we reported that Dynomighty, a Kickstarter-like operation, was seeking funding to produce an anole themed wallet. And sure enough, they got enough backers (who wouldn’t want to support development of such a needed product?). So get yours today–only fifteen bills.

And once you do, open them up to buy these anole pillowcases.

What Lives in Bromeliads High in Trees in the Rainforest?

Anolis transversalis. Photo by Bejat McCracken.

Anolis transversalis. Photo by Bejat McCracken.

AA reader Shawn McCracken writes:

While conducting ground-level herpetofauna surveys at the Tiputini Biodiversity Station in Ecuador’s Yasuní Biosphere Reserve, I was lured to the canopy by the cacophony of what had to be undiscovered species coming from the bromeliad, orchid and epiphyte microhabitats. This led me to think how many possible new species may be living in this new frontier? While birding at the canopy towers I saw the Tropical Thornytail Iguana (Uracentron flaviceps) and Banded Tree Anole (Dactyloa [Anolis] transversalis) scurrying about in some of the adjacent trees, amongst other anoles I could not quite identify, there was no doubt I was headed up. Of all the available microhabitat in the canopy, the big tank bromeliads caught my attention the most – little swamps, everywhere at 20+ meters off the ground. Surely there had to be herpetofauna using these as a resource and refuge in the harsh canopy environment.

Aechmea zebrina, the bromeliad species examined by McCracken and Forster.

Aechmea zebrina, the bromeliad species examined by McCracken and Forster.

Before the next field season, I decided I needed to get up into the canopy and collect some bromeliads to have a look inside. After a self-taught crash course in tree climbing, I returned to Tiputini, but quickly realized I didn’t have a long enough rope or the skills to get to those big bromeliads. Packing plenty of rope and a greater confidence in my climbing abilities, I returned for another field season the next year. This time was a success. Along with my assistants, we collected 40 bromeliads representing three species that we sealed in 55-gallon trash bags and carried back to camp. Once we began dismantling the bromeliads, we realized we had hit a treasure trove of invertebrates and herpetofauna. Now several years later and a total of 240 bromeliads collected, we have a pretty good idea of the herpetofauna utilizing canopy tank bromeliads in northwestern part of Yasuní. In this latest publication, we summarize the herpetofauna of one high canopy tank bromeliad species, which includes the gecko Thecadactylus solimoensis and two anoles, Anolis ortonii and A. transversalis.

Some other bromeliad denizens

Some other bromeliad denizens

New Song about Night Herping

CD Stomping Grounds

We’ve heard a lot about Gunther Köhler in the last few days. What you might not know is that when he’s not busy snatching sleeping lizards off of leaves in the highlands of Mesoamerica or counting scales in his Frankfurt laboratory, he plays guitar in a flaggstaff, a country band. The band is about to release its latest CD, Stomping Grounds, and one single, Chiriqui Stream, is appropriate for our pages. You can download the MP3 and then sing along:

Chiriqui Stream

  1. When the nights grow late and the fires die down

When the fog and mist start boiling around

At camp site down by the Chiriqui stream

Where we search for creatures nobody’s seen


  1. The thrill of the night hike blows you away

As we move on, magic’s underway

We poke through the forest with its pines and oaks

With the sound of the woods, the creeks and slopes


Chorus: Living my dream at the Chiriqui stream

Finding my fortune in this unreal scheme

With a family of creatures nobody’s seen

Right down at the Chiriqui stream


  1. On the fog shrouded slopes and rugged peaks

A world of its own with its lovely creeks

Its unforeseen bugs and mystical sounds

No doubt we’re here on unknown grounds

The Lizard Bites Back: Crested Anole Bites the Head of an Attacking Snake

Photo by Benny Diaz

Photo by Benny Diaz

AA stalwart Liam Revell was forwarded the photo above on Facebook and decided to look into it. Here’s what he reports:

This impressive photo showing a Puerto Rican crested anole (Anolis cristatellus) being attacked by a Puerto Rican racer (Borikenophis portoricensis) was recently posted to the Facebook group ‘Biodiversidad de Puerto Rico’ by a photographer Benny Diaz. He has kindly allowed us to re-post his photo here and also supplied the following description of the predation event he witnessed transpiring in the Puerto Rican state forest Bosque Estatal Guajataca (translated from Spanish):

“I first saw this anole and tried to take a photo of it after noticing that it was marked with two different colored spots of paint on its back. As I slowly approached it, the animal suddenly reacted with a jump and just at that moment a Puerto Rican racer (Borikenophis portoricensis) appeared out of nowhere and captured the anole in midair!”

Although the predation event is remarkable in itself (and the photo capturing it terrific), perhaps even more notable is the fact that the lizard appears to have been marked by an investigator conducting research on anoles! After some (social media-aided) investigation of the matter, led by Puerto Rican USFW biologist and avid photographer J.P. Zegarra, this scientist revealed herself to be University of Puerto Rico Ph.D. candidate, and friend of Anole Annals, Luisa Otero. Luisa is studying anoles in Puerto Rico as part of a multi-institutional collaborative NSF project to investigate the vulnerability of tropical ectotherms to global climate change. More can be learned about this project, and Luisa’s research, from the project website.

Luisa recounts the following about this particular lizard:

Yes, we took the Tb (Editor’s note: body temperature) of the poor lizard in the picture a few weeks ago in Guajataca. Prof. Hertz was here and we were taking body temperatures and operative temperatures from models. It was the last trip of the ‘ vulnerability of tropical ectotherms’ project!! I usually use paint to mark the lizards so we don’t re-sample them the same day. This poor guy was sampled two days in a row…. (that’s why it has two colors)… and a few weeks later was eaten by this Alsophis (Ed. recently renamed Borikenophis)… very sad.”

Some years ago, Manuel Leal and Javier Rodríguez-Robles conducted a study in which they investigated what happened when a Puerto Rican racer confronted a crested anole. I summarized the study in Lizards in an Evolutionary Tree:

“In laboratory trials, Leal and Rodríguez-Robles (1995) showed that the snake, (which can attain a length of more than 1m), attacked anoles much less often  when the lizard displayed. Moreover, they demonstrated that when attacked, the lizards fought back, often biting the snake on the snout for as long as 20 minutes and managing to escape in 37% of the encounters (Leal and Rodríguez-Robles, 1995)—remarkable given the size discrepancy of the snake and the lizard.”

Diaz’s observations confirm that this behavior is not a laboratory artifact–crested anoles will chomp down and hang on for all their worth. But, just as in the majority of the lab trials, the valiant defense was for nought. After a few minutes, Diaz reports, the lizard

appeared to be immobilized (probably the result of the rear-fanged snakes venom) and the snake began to work the lizard around, little by little, until it was able to swallow it head first.

Photo by Benny Diaz.

After the lizard let go of its grip, the snake slowly moved its grip up the lizard’s body. Photo by Benny Diaz.

The time between the first photo (above) and the last one (below), in which the lizard is well on its way to digestion, was eight minutes.

Photo by Benny Diaz

Photo by Benny Diaz

It’s also worth mentioning the follow-up study Leal conducted. Again from Lizards: “

In field trials, Leal (1999) found that the extent of display behavior toward a snake model correlated with the endurance capacity of the lizard (as determined in subsequent laboratory trials); the greater the endurance capacity of the lizard, the more it displayed to an approaching snake model. Anole displays to predators may be an example of a pursuit deterrent signal (reviewed in Caro, 2005). By signaling their endurance capability, anoles may be indicating their ability to fight back, escape, and potentially even injure a snake (Leal, 1999).”

Cannibalism in Anolis sabanus and Other Anoles

cannibal sabanus

In the most recent issue of IRCF Reptiles & Amphibians, Powell and Watkins provide an eyewitness account of an adult male Anolis sabanus killing a juvenile, presumably en route to eating it (which occurred off stage). The paper also provides a listing of other documented cases of Caribbean anole cannibalism, of which A. sabanus becomes the 19th species known to eat its own.

Editor’s Note: The IRCF webpage appears to be down. You can access the paper here.

Lizard Olympians Benefit from Training Just Like Their Human Counterparts


Husak Lab member Erik Sathe putting a lizard through its paces. Photo by Jerry Husak

Husak Lab member Erik Sathe putting a lizard through its paces. Photo by Jerry Husak

AA contributor Jerry Husak has just published a great paper in The Journal of Experimental Biology on the effect of training (=practice) on the sprinting and endurance capabilities of green anoles. The Inkfish blog on Discover magazine’s website has written a brilliant description of the study:

Athletes don’t normally need to be chased down the track to get their training mileage in. But a green anole lizard is not a normal athlete.

Scientists wanted to know whether it’s possible to train a lizard at all. Human athletes and other mammals perform better with consistent exercise, but is this universal? Can a reptile increase its stamina? What about its sprint speed? So the scientists became lizard athletic trainers, which really means lizard harassers. Results were mixed.

The green anole lizard, or Carolina anole (Anolis carolinensis), is a common laboratory species. Basic rules of its biology—for example, how it responds to exercise—ought to apply to other vertebrates, such as humans. In the past, scientists have successfully used exercise to increase endurance in frogs, birds, alligators and crocodiles. But the same efforts with lizards have been inconclusive.

Jerry Husak, a biologist at the University of St. Thomas in Minnesota, studies lizards with the help of undergraduate researchers. He and his students decided to try creating “Olympic lizards.” They would train their subjects for two kinds of athletic ability, neither of which was totally foreign to the reptiles. Some lizards would become endurance athletes; this long-distance locomotion would mimic the slow patrolling and foraging anoles do in nature. And other lizards would become sprinters; in nature, they use bursts of speed to escape predators.

Thirty lizards were divided into sprinters, distance runners, and a control group. The sprinting track was a dowel two meters long and five centimeters wide, propped at a 45-degree angle. The researchers chased the lizards up the dowel and used infrared beams to measure their fastest speed. Sprinters “trained” three days a week for eight weeks. Gradually, the researchers increased the training intensity by making the lizards do more runs per day.

Meanwhile, the distance runners did their training on a treadmill. The researchers set the treadmill to a low speed and gently prodded the lizards with a paintbrush to keep them moving. These athletes had to stay on the treadmill for 30 minutes at a time, or until they were exhausted. (How do you know anoles are exhausted? “When we flip them over onto their backs and they can no longer flip themselves back onto their feet,” Husak explains. Glad he’s not my trainer.) These lizards, too, exercised three times a week for eight weeks, while the steepness of the treadmill gradually increased.

At the end of the training regimen, the researchers tested all their lizards a final time. The distance runners had clearly improved. On a fast treadmill, the endurance-trained lizards could run for almost three times as long as they had initially. Blood samples showed that their hematocrit levels—a measure of red blood cells, which carry oxygen—had also increased. And dissecting the limbs of dead lizards revealed that their muscle fibers had grown, just as they do in exercising mammals.

The sprinting lizards were a little more disappointing. In their final trials, they didn’t run any faster than they had before training. But their muscle fibers had also grown. Husak suspects that these athletes had actually improved—they just didn’t feel like performing.

“I definitely think the sprint-trained ones increased their sprinting abilities,” Husak says. But after the lizards had spent so much time being handled by humans, he says, “We just couldn’t motivate (i.e., scare) them enough…to run as fast as they could.”

There’s not likely to be a lizard Olympics anytime soon. Creating athletic anoles isn’t the only goal of Husak’s research, though. He’s ultimately interested in the tradeoffs that come with being a good athlete. Animals that spend more energy on reproduction, for example, may have to sacrifice life expectancy or immunity. Do the same tradeoffs happen when animals spend their resources to build beefy muscles?

Husak has gotten closer to answering that question by showing that lizards can be trained. Now he just has to figure out how to scare them into performing their best—because even if the biology of exercise is the same across vertebrates, the power of a “Just Do It” poster isn’t.

Anolis lividus Is HHMI Biointeractive’s Image of the Day

The post doesn’t say much, but it’s nice for this lovely anole to get the attention it deserves!

If you search for photos of A. lividus online, there aren’t all that many. Several more nice ones have appeared previously on AA, such as this one:

Photo by Jim Hewlett


and here’s one from Calphoto:

If you want to read more on this not-well-studied species from an island recently ravaged by volcanoesAA is the place [1,2].




New Study on the Habitat Use of Day Geckos

Phelsuma guimbeaui from Mauritius.

Despite the brilliant colors, the natrual history of day geckos (Phelsuma) is little known. The most recent issue of Herpetological Conservation and Biology includes a very nice study on the habitat use of two Mauritian species, showing that they are most abundant in native forest and pointing out that, thanks to their pollinating services, they are keystone species. An interesting point is that even though day geckos are essentially Old World anole doppelgängers, in their habitat use they differ in rarely leaving the trunks of trees. One of the authors is legendary ornithological conservationist Carl Jones, almost single-handedly responsible for preventing the extinction of several Mauritian bird species.

Here’s the abstract:

Many fragile ecosystems across the globe are islands with high numbers of endemic species. Most tropical islands have been subject to significant landscape alteration since human colonisation, with a consequent loss of both habitat and those specialist species unable to adapt or disperse in the face of rapid change. Day geckos (genus Phelsumaare thought to be keystone species in their habitats and are, in part, responsible for pollination of several endangered endemic plant species. However, little is known about key drivers of habitat use which may have conservation implications for the genus. We assessed the habitat use of two species of Phelsuma (Phelsuma ornata and Phelsuma guimbeaui) in Mauritius. Both species showed a strong affinity with tree trunks, specific tree architecture and are both restricted to native forest. Tree hollows or cavities are also important for both species and are a rarely documented microhabitat for arboreal reptiles. Both P. ornata and P. guimbeaui avoid areas of high disturbance. Our data suggest that active conservation of Phelsuma requires not only the protection and restoration of native forest, but also implementation of forestry practices designed to ensure the presence of suitable trees.