WTF Anole Evolution?


The website WTF Evolution has been popping up around the ecology and evolution blogosphere lately. It was recently featured by Jerry Coyne at Why Evolution is True and by Jeremy Fox at Dynamic Ecology. However, if you don’t read either of these blogs, or haven’t heard about the site, I suggest having a look – it’s pretty funny (especially ‘Fiddler crab’). Best of all, however, is that anoles are featured (and they’re the only organism to get a video)! The example is one featured on Anole Annals previously and is from a study by Casey Gilman in Duncan Irschick’s lab. The video shows that when anoles jump from springy perches, the recoiling perch can hit them in the tail, throwing them off balance. As the captionist at WTF Evolution notes, not a great thing for a lizard that spends a lot of time on branches: “Great work, Evolution“.

 

Anolis Barbatus Mating!

Photo by Chuck Horne

I certainly was not expecting to see this so soon! According to the breeder, these anoles were only 3-4 months old when I received them last month (December 4th). Unfortunately, I did not take SVL measurements at first but they have certainly grown in the 1.5 months I’ve had them (the male seemingly more so than the female). I’ve placed a “nest box” in the enclosure with a commercial, tropical blend soil medium and I will check it for suitable “dampness” periodically in the hopes it makes an acceptable laying site. I’d appreciate any advice AA members may have to increase my chances of successfully incubating eggs and raising the babies. I’ll post updates periodically.

How Is A Baby Anole Like An Insect?

Green anole, emerging on the experimental scene. Photo by Justin Walguarnery.

They really are small. Photo by Justin Walguarnery

In their rate of heating and cooling. A recent paper by Walguarnery et al. reveals that baby green and brown anoles change temperatures at a remarkably rapid rate, much higher than that reported for most other vertebrates and comparable to that of insects. The reason would seem to be obvious: they are small, with a large surface-to-volume ratio, and thus they gain and lose heat rapidly. Moreover, the typical lizard posture, with body resting on the substrate, enhances the rate of conductive transfer of heat.

Brown anoles, too. Photo by Justin Walguarnery

The authors point out that this finding has interesting implications for our understanding of habitat partitioning between species. In particular, if the body temperature of juvenile anoles very rapidly equilibrates with the operative environmental temperature of the exact spot they occupy, then individuals can very precisely regulate their body temperature, whereas the slower change of larger lizards makes it more difficult to finely adjust body temperatures by moving from one spot to another.

As part of the study, the authors also measured the preferred body temperature of lizards in laboratory gradients and found that juvenile green anoles preferred to be 2 degrees warmer than brown anoles. This result is particularly interesting because previous work on adult lizards had found that brown anoles prefer warmer temperatures. Assuming that this is a real effect and not an artifact of differences between the methodologies of the two studies, this finding raises interesting questions: why do temperature preferences change ontogenetically, and what implications do these changing preferences have for patterns of habitat partitioning? From my own personal experience, adult brown anoles usually appear to occur more frequently in hot and exposed positions than green anoles, and it hasn’t been obvious to me that the habitat use of juveniles of the species is any different, but I have to admit I haven’t paid that much attention to the little fellas. Like anole biology more generally, the thermal ecology of juvenile anoles is a little explored and potentially important area for future research.

But enough of my blathering. Let’s hear what the author, Justin Walguarnery, has to say about the paper:

“The study was conducted as part of a series of investigations into how two of the most widespread Anolis species interact early in life. In particular, we were interested in identifying patterns of behavior and physiological ecology present immediately after hatching. Our goal here was to observe species characteristics defining the fundamental niche that might be constrained, modified, or obscured later in life. Continue reading

Miami Anole Safari I

Jason Kolbe’s latest field site

Wonderful as the International Biogeography Society meeting was, there were more important fish to fry in Miami, so several of us played hooky to go looking for introduced anoles. First stop was Miami Beach, where we headed to the famed Fountainebleau Hotel, site of an introduction of A. trinitatis from St. Vincent (note to Wikipedia-adept readers; the entry  for the hotel is quite informative, but lacks information on the hotel’s pivotal role in enhancing Miami anole diversity). Last year, Joe Burgess reported that the colony was no more, but we wanted to check for ourselves.

Slipping into the pool area at the back of the hotel, we inconspicuously mingled with the beautiful crowd, gazing up the enormous palm trees and into the bushes, pretending to be looking for birds and lost croquet balls. The morning was semi-sunny, but very windy—not ideal anole weather, especially when looking for a species hailing from near the equator. Nonetheless, when the sun peeked out, we did find the Miami big three—carolinensis, distichus and sagrei—but no sign of trinitatis. After an hour, with the security team moving in, we decamped through the back and headed on.

Next stop: the lush and beautiful grounds of the Fairchild Tropical Botanical Garden, its floral magnificence seemingly designed to provide ideal saurian habitat. We first visited the new Wings of the Tropics building, a lovely, enclosed house full of brilliant eye candy in the form of morpho, postman, and other fabulous butterflies. We stopped in there because word on the street is that the building will soon be re-named Toepads of the Tropics because some uninvited guests have taken up residence in the well-vegetated exhibit, enjoying the sun and the abundant insect fare. Sure enough, we spotted both a brown anole and a female red-headed Agama agama.

Floridian red-headed agama. Photo from dust tracks on the web

“Agama”??? you say? That’s right, these lovely African lizards have taken root in a number of places in southern Miami, amongst them the Fairchild. And in a biomically-appropriate way, these East African lizards are most common in the Old World Xeric exhibit in the gardens, hanging out amongst the Malagasy euphorbs and pachypodia, probably imaging that they’ve just slipped across Mozambique Channel. To complete the illusion, they have taken pains to scare away all the anoles from their rocky redoubt, though we did notice one brave male brown anole in the shade of a rock. Agamas may have the same effect on anoles as do curly-tailed lizards, a suggestion made by James Stroud, who was our very capable tour guide to the lizards of Fairchild.

By then, the sun was out in full force and the anole abundance was extraordinary. Continue reading

Tissue for genetic material: options other than tail tips?

I was hoping to get suggestions from the readers of AA about methods of tissue collection for genetic work other than tail tips. I’ve been working with the agamid lizard Sitana ponticeriana, and my work is now taking decidedly genetic directions. It remains unclear whether or not these lizards regenerate their lost tails–while they seem to lose tails easily, I didn’t see any lizards with noticeably regenerated tails in the field. Given this, I am a little uncomfortable with the idea of taking tail tips as tissue for genetic work. Are there other common and easy options for sampling tissue from lizards? Many thanks in advance for your responses!

(Feel free also to weigh in with whether or not you think it acceptable to collect tail tips in a species that certainly autotomizes its tail but does not grow it back–it seems like a grey area to me).

A male Sitana ponticeriana near Pune, India.

New Species Of Chamaeleolis!

AA contributor and anole breeder extraordinaire Veronika Holáňová and colleagues have just described a new species of Chamaeleolis, Anolis sierramaestrae, from–where else?–the Sierra Maestra of eastern Cuba. The species, described in a paper just published in Acta Societatis Zoologicae Bohemicae, differs in a variety of scalation details from the other five species in this group, and the paper includes a very useful pictorial guide to distinguishing among them.

In addition, check out this nifty x-ray.

Anolis Sagrei Invades Mainland Asia

Who knows how far this fellow’s genes will spread through Asia?

These pages have chronicled the appearance of the brown anole (Anolis sagrei) in farflung places around the globe, including throughout the CaribbeanHawaii, Costa Rica, and Taiwan, among others. A new paper in Nature in Singapore reports a first: an established population in mainland Asia, in Singapore. The site of the invasion, and apparently for now the only locality for the population, is a new park, Gardens by the Bay. As Wikipedia reports, Gardens by the Bay is “an integral part of a strategy by the Singapore government to transform Singapore from a “Garden City” to a ‘City in a Garden’. The stated aim is to raise the quality of life by enhancing greenery and flora in the city.” Like many invasive anole populations, this one probably was founded by stowaway lizards or eggs transported in potted plants, but this is just conjecture.

As a sidenote, as far as I am aware, this paper is the first to implement the new Nicholson et al. anole classification, explicitly citing the paper as rationale for referring to the species as Norops sagrei.

IBS Update: Sub-Fossil Anoles on Anguilla

Hello once again from the IBS in Miami. As I mentioned in my last post, anole presentations are a little thin on the ground here (though not around the conference centre where, with the help from some locals, we saw sagrei, carolinensis, equestris and distichus today).

I did have the opportunity yesterday to check out the the second of two anole presentations here – a new look at the sub-fossil lizard communities, with a focus on a question familiar to many readers of this blog: What’s the deal with A. pogus on Anguilla?

Has A. pogus ever been on Anguilla? Nope.

The study is being led by Melissa Kemp, from Liz Hadly’s lab at Stanford. Melissa has re-analyzed lizard dentaries from excavations on Anguilla that featured heavily in an anole character displacement versus taxon cycle debate in the early 90s.

By analyzing the size distribution of anole dentaries dating back 10,000 years on Anguilla, Melissa argues that not only is there a lack of evidence for a taxon-cycle involving A. pogus, but that there’s no evidence that A. pogus has occurred (in meaningful numbers) on the island at all! To further test this, Melissa has sequenced a portion of cytochrome b for five specimens thus far, all of which have turned out to be A. gingivinus, with more sequences coming down the pipeline.

Anoles aren’t the only lizards Melissa has uncovered – with Thecadactylus, Ameiva and Leiocephalus all present. Anoles have dominated the fauna in all but the earliest (and sparsely sampled) time slice and Leiocephalus was historically present (but probably not abundant) but disappeared several thousand of years ago and has not reappeared in the sub-fossil record since.

This was my first exposure to sub-fossil analysis of lizard communities and I was definitely impressed. I don’t have a sense of how much similar work there is in the literature (but I’m sure readers of the blog can educate me), but there seems substantial scope to collaborate with zoo-archaeologists to get more specimens and data on past trait variation and anole assemblage composition.

Considered breeding anoles in situ?

If you are lucky enough to live in the tropics then you can do away with incubators, endless tinkering with temperature, humidity and light regimes and let nature do it for you. I have been breeding A. apletophallus in Panama for almost two years and thought I should share with you my take on breeding anoles “in situ.”

Left: Mesh cages hanging in the shade house. Right: Newly emerged hatchling.

I use a very basic shade house that is situated on the edge of the forest. The temperature and humidity are similar to the forest where the lizards live. In the shade house, the lizards are housed individually in mesh cages that I constructed from pop-up laundry hampers and mesh bags. Each cage is outfitted with three branches and a plastic leaf. Females have a shallow soil plate to lay eggs in, which they happily do. I feed adult lizards every three days and at the same time check for eggs. All eggs are removed and placed in a plastic cup with water and cotton wool, which is then placed inside a ziplock bag. Eggs are “incubated” at ambient temperature (~45 days). When the eggs hatch the hatchlings are transferred to plastic boxes with a mesh lid. These “baby boxes” also contain three small branches and a plastic leaf. Hatchlings and subadults are feed every other day. All lizards are sprayed daily with water. Although there is probably room for improvement, this has been a successful and economical strategy to breeding anoles in the tropics. For anyone who wants more details I have posted this on my webpage under “animal husbandry.”

Where Are The Anoles?

Missing anoles? Or missing anole biogeographers?

As you may (or may not) know, the 6th meeting of the International Biogeography Society (IBS) is underway in Miami, FL.

So here I am, in the anole invasion capital of the world, with the Caribbean on the doorstep, and a look through the conference program reveals a paltry TWO talks on our favourite lizards. Contrast this with Martha Munoz’s reports from SICB, with 18 (or so) anole talks. Of course, there’s something to be said for quality over quantity and the two anole presentations here do a good job of flying the flag. Yesterday Jonathan Losos kicked off one of the symposia with a talk on anole traits, function and biogeography (with a smashing blue / yellow colour scheme), and later today I’ll be searching out a poster on anole fossil assemblages (post forthcoming)

Nonetheless, I still can’t help wonder, where are the anole biogeographers? You can’t look through a text on island biogeography, species area curves or adaptive radiation without finding a dewlap. So the question is, are people not doing anole biogeography anymore? This isn’t the case, so it can only be that either the IBS isn’t on the radar, or people choose not to go. Either way, you’re missing out on a great meeting – it’s an excellent opportunity for the anole research community to radiate and reach a slightly different audience.

Amber Geckos From The Dominican Republic

We’ve had a lot of hoohaw in these pages about amber Anolis, but anoles are not the only lizards represented in the Dominican amber fauna. In particular, a number of fine specimens of amber geckos are known from the D.R., as well as from amber deposits elsewhere. One such species is Sphaerodactylus dommeli. Embarrassing as it is to anole aficionados, this specimen has at times been suggested to be an anole, hard as it may seem to confuse such a lowly gecko with something as magnificent as an anole. In any case, Daza et al. have just published a magnificent analysis demonstrating that the specimen is, indeed, a gecko, and providing tips on how to avoid such unwholesome confusion in the future. Moreover, confirmation of the specimens identity will allow it to be used as a calibration point in future molecular studies of Sphaerodactylus phylogeny.

A Tenuously Anole-Themed Public Service Announcement

Regular readers of Anole Annals will know that, like humans, anoles are parasitized by malaria. It’s a different lineage of malaria specialized for lizards but it is malaria none-the-less.

What readers of Anole Annals might not know, however, is that anoles don’t seem to suffer from the cold, the flu, or whooping cough (not according to a quick literature search, anyways).

These illnesses do afflict humans, however, and this winter season is shaping up to be a serious one. Perhaps you have already experienced this.

Top things to do to avoid getting and/or passing on the flu this season:
1) Wash your hands frequently.
2) Avoid touching your mouth, nose, and eyes.
3) Stay home if you’re sick. Keep your kids home if they’re sick. And encourage your colleagues to stay home if they’re sick.
4) Get your flu shot and your pertussis booster.
5) Encourage your friends to get their shots too. Herd immunity!
6) Develop lizardy super powers that render you invincible.

PS: The flu-shot cannot give you the flu by accident. This is a pernicious myth. The virus particles injected in the flu shot are dead, zapped, kaput. You may feel a little under the weather as your body works to develop antibodies but that’s a whole lot better than getting the actual flu. I felt fine after my flu shot.

Snail Chomping Lizards

Although Anole Annals is devoted to all things anoline, we try not to be too parochial. In particular, when fascinating items appear in print or cyberspace on other lizards, we try to report them here, especially if they have some relevance to matters anole.

In this vein, we wish to draw attention to an interesting communique that just appeared in Tetzoo, a fascinating site dealing with a wide range of topics, and taxa, concerning tetrapod zoology. The article in question discussed snail-eating in the Australian pink-tongued skink (a rosy version of the blue-tongued variety) and the broad crushing teeth seemingly designed for such a purpose, teeth that are parallelled in a fossil marsupial.

Chamaeleolis teeth from Estes and Williams. Ontogenetic variation in the molariform teeth of lizards. J. Vert. Paleo. 4:96-107.

The relevance to anoles, of course, is that one of our very own, the Chamaeleolis clade, exhibits very much the same trait of snail crushing, as illustrated in a previous post.

Anole Dance Craze From The 1920s

In the 1920’s, there was a dance as popular as the Charleston, but it was about anoles! Admittedly, it was called the “chameleon,” but clearly it was based on pictures of an anole, and you can evaluate the dance moves yourself to decide if they were more anole- or chameleon-like.

Apparently Luke Harmon, who brought this video to AA‘s attention, is an expert at many of the moves involved in the dance.

Frogs Are Lovers; Anoles Are Fighters – Updates From SICB

Sometimes anoles are lovers, too. But even when they love, they seem to fight. Photo of Anolis carolinensis taken from Wikipedia.

Greetings again from San Francisco! The anticipation for  yesterday’s Animal Communication session was palpable. Usually a big Anolis hit at SICB, the Communication session did not fail to impress. The session was divided into two sections – Lovers and Fighters. Can you guess which one had all the anole talks? Three out of the five talks in the Fighters session were about anoles. Incidentally, most of the talks in the Lovers session were about tree frogs. This was perfectly to my liking – I’ll take the blood, guts, and gore any day. The three Anolis talks presented fascinating new work.

The first was by Jessica Edwards, a graduate student working with Simon Lailvaux at the University of New Orleans on aggressive encounters between Anolis carolinensis and A. sagrei, which has successfully invaded much of A. carolinensis‘ range. In a previous study, Jessica and Simon found that A. carolinensis tends to perch higher in the presence of A. sagrei than when found alone.  For her experiment, Jessica placed one male of each species into a large cage with a single perch. At the top of this perch she placed a heat lamp, so that there was one optimal site (warm top) and one sub-optimal site (cool bottom) on the perch. She then scored behaviors and recorded the victor in each trial.  She found that relative dewlap size was a good predictor of trial outcome, and that the each species was about equally successful at obtaining the optimal perch, although A. sagrei did have a slight advantage. She repeated this experiment using females of each species, and found something exciting and perhaps unexpected – Anolis sagrei was the clear victor in all but one of several dozen trials! Jessica posits that, in the wild, female A. sagrei push female A. carolinensis higher up in the trees. In polygynous systems such as anoles, where one male defends a group of two or more females, then we would expect the males to go where the females do, and so would expect males to increase their perch heights, as well.

Continue reading

Updates From SICB – How Does Climate Warming Threaten Anoles?

Anolis bicaorum from Utila, Bay Islands, Honduras. Photo by J. Losos.

Will global warming allow the blue-headed anole, A. allisoni, to move into the forest in the Bay Islands? This individual was photographed on Roatan by J. Losos.

Climate warming is a sad reality that environmentally defines our era. Over the next century, conservative estimates suggest that air temperatures will rise about 3° C. One imperative in research is to try to understand how reptiles, whose physiology is tightly linked to thermal environment, are going to be impacted by these increasing temperatures. During a symposium honoring Ray Huey, a leading biologist (and an anologist, to boot!), Michael Logan of Dartmouth College gave a talk on how small-scale estimates of thermal variation, rather than weather stations, yield interesting and perhaps counterintuitive results for how tropical lizards will be impacted by hotter temperatures. Predictions of potential impact to date rely heavily on temperature data gathered from weather stations – those provide a resolution of one square kilometer. For small reptiles, like tropical anoles, he argues that we need a finer resolution. To this end, Logan launched several operative temperature devices (sensors that perceive temperature as a lizard would, rather than just air temperature) on Cayo Mayor and Utila, which are islands in the Bay Island Archipelago in Honduras. We’ve discussed the anoles of the Bay Islands here on our blog before. On Cayo Mayor, Anolis lemurinus is found in the closed-canopy forest, while the blue-headed lizard,  A. allisoni is found in more open habitats. A close relative of A. lemurinus, Anolis bicaorum, is found throughout Utila. Because closed-canopy forests are more thermally homogenous (less variation in available temperatures due to less access to sun and shade patches), the expectation is that, under a scenario of climate warming, the open habitat species A. allisoni should be able to invade A. lemurinus‘ habitat. Logan says that A. allisoni will not invade the forest habitat, although the details of the analysis suggest to me that they might. From what I saw, increasing temperatures in the forest should allow A. allisoni to invade the newly available warm habitat. He does find that A. lemurinus should experience a loss in potential daily activity hours because of increasing temperatures, putting this species at risk. The common species (A. bicaorum) will actually experience more hours of activity and likely benefit, at least in the short term, from increased temperatures. Logan concludes that more micro-scale measurements provide the appropriate resolution for studies of thermal performance in lizards, and will be the wave of the future.

Ecuadorian Anole ID Needed

Photo by Brian Arbogast

Brian Arbogast sent these photos with a request for identification. I have my guesses, but I thought I’d throw it out to the experts. Here’s what Brian had to say: “They were taken in the lower cloud forest of Sumaco Volcano, on the eastern slope of the Andes in Ecuador at about 1700-1800m in elevation.”

Photo by Brian Arbogast

Day One Updates From SICB

Greetings again from San Francisco! Day One of SICB has been full of amazing talks and posters. The poster session yielded interesting new research by Diego Castro and Michele Johnson, of Trinity University, on the relationship between testosterone and dewlapping behavior. Diego, an undergraduate studying neurobiology, asked whether muscles involved in sexual or aggressive behavior would have increased testosterone. To answer this question, Diego focused on five species of Dominican anoles, including Anolis brevirostrisA. coelestinus, A. cybotes, and A. olssoni. Diego observed the natural behavior of these species, and quantified the average number of pushups and dewlaps they performed. They found that A. coelestinus and A. cybotes have fewer dewlap extensions and several pushups in their displays, while A. brevirostris dewlaps as often as it performs pushups. They then quantified the concentration of androgen receptors in the ceratohyoid, which controls dewlap extension to determine whether levels of androgen receptor protein correlate with sexual display behavior. They found that species with greater display rates also had a higher number of cells expressing androgen receptor protein. Their next goal is to measure androgen receptor protein in the bicep and tricep. Great job, Diego!

 

Winners Are Right-Brained – Visual Lateralization In Aggressive Encounters

Aggressive encounter between anoles. Both opponents are watching each other with their right eyes. Photo: Johnson Lab, Trinity University

Have you ever gotten an angry look from an anole? Has he ever displayed at you, demanding that you get out of his territory? If so, chances are that if an anole was giving you the stink eye, he with using his left side! I’m blogging live from the Society for Integrative and Comparative Biology (SICB) meeting in San Francisco. My first stop has been to view Michael Patton’s poster examining the neuroanatomy of aggressive behavior. Patton is a senior undergraduate student at Trinity University working with Dr. Michele Johnson. Early birds at SICB have the opportunity to put their posters up for early viewing, so I got a sneak peek of his work last night although he’s not slated to present until Saturday.

For his project, Michael addressed the question of brain lateralization in aggressive displays. Some evidence suggests that anoles tend to favor their left side during competitive encounters. Patton and colleagues built on these studies by examining behavioral laterality in the field and neuroanatomy in the lab in the same individuals. Through observations of wild A. carolinensis, Patton found support for this idea – the winning male tended to view his opponent from his left side!

Continue reading

Color Catalogue For Field Biologists


Anole biologist Gunther Köhler has produced a handy manual, available from Herpeton publishers, to help describe colors of specimens, especially in field situations. The book’s introduction can explain better than I what it is used for and why it was written:

The accurate description of the coloration in life of organisms represents an important component of the work of any field biologist. Subtle differences in the coloration in life, such as in the color of the iris, the lining of the mouth cavity, or the tongue are diagnostic for certain species and have been used by taxonomists to differentiate among species.

Whereas many aspects of the external morphology of scientific specimens can be preserved with proper fixation methods, there is still no way to assure the long-term conservation of the coloration in life in such specimens. This is especially true for animals traditionally fixed with the help of formalin and ethanol, such as fishes, amphibians, and reptiles, and then stored as a wet collection. Colors such as red, yellow, and orange disappear rapidly once the specimen is placed in the preservative. Green-colored amphibians and reptiles can turn blue, lavender, purple, or black within a short time after preservation.

The Catalogue also provides definitions and examples of different phenotypic characteristics.

Of course, taking photographs of animals helps to document the coloration in life. Possible drawbacks to this technique are incorrectly adjusted white balances, which cause colors not to be reproduced accurately. Also, photographs often do not show coloration of hidden body parts. Therefore, biologists have a long tradition of recording colors by making written descriptions. Since individuals see colors differently and because it not easy to define, for example, different shades of brown or green in words, having a color standard helps to produce more objective and detailed descriptions that also have a greater chance of being reproducible. Such a reference can be used to compare descriptions made by different persons at different times and places. For decades, field biologists have utilized the “Naturalist’s Color Guide” by Frank B. Smithe (1975-1981) as the standard reference for color descriptions. However, for many years now, this important reference has been out of print and is no longer available.

I have used Smithe’s “Naturalist’s Color Guide” (called “Smithe Guide” from here on) extensively during the past 20 years, and my copy now clearly shows signs of this intensive usage under field conditions over the years. With no hope of being able to obtain a copy in good shape to replace my old one, I decided to produce a new reference to fill the gap left by the now unavailable Smithe Guide.

The resulting “Color Catalogue for Field Biologists” you are holding in your hand is not a duplicate of the Smithe Guide. Continue reading