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The first three paragraphs of Jane Peterson’s contribution to the Second Anolis Newsletter.

Jane Peterson’s contribution to The Second Anolis Newsletter remains one of the most comprehensive exemplars of functional-morphological research of the anoline appendicular girdles. In just a few short paragraphs Peterson (1974) outlined the key differences in pectoral girdle morphology between the Anolis ecomorphs, drawing information from both field observations and anatomical dissections of anoles from all four Greater Antillean islands. The outlined study could have formed a major contribution to our understanding of ecomorphology, had these brief observations ever been expanded into a scientific publication. Sadly, they remained as notes, confined to a brief communique on an informal basis (that continues to be formally cited). Several intriguing studies hence have examined anole appendicular morphology, but rarely allowed for implications that reach across multiple island radiations (e.g. Anzai et al. 2014, Herrel et al. 2018).

With my 2016 Ph.D. thesis, I set out to quantify what Jane Peterson had observed forty years prior, and must confess that I still fall short of reproducing the multitude of implications that Peterson’s (1974) brief descriptions alluded to. Instead of combining video-recorded movement cycles with morphological descriptions, my comparisons are solely based on three-dimensional shape analysis of the skeletal elements that comprise the breast-shoulder apparatus (BSA): the clavicle, interclavicle, presternum, and scapulocoracoid (Fig. 1). Employing the power of computed tomography scanning, and geometric morphometric analysis, I quantified the shapes of the central elements of the pectoral girdle, and compared these across anole radiations.

As with earlier work, I focused on the Jamaican ecomorph representatives, and sought out their ecomorph counterparts from Hispaniola and Puerto Rico, particularly targeting those species that are the most and least similar to the Jamaican forms. That last line of thought did not reveal any straightforward answers, as the complex structural shape of the BSA allows these anoles to be relatively distinct in some aspects, while being quite similar in others. For example, the general shape of the presternum and interclavicle are quite similar between the two trunk-ground anoles Anolis lineatopus (Jamaica) and A. gundlachi (Puerto Rico), while that of the scapulocoracoid differs quite remarkably between the two. These complex associations will take a more detailed analysis than what is warranted here, so I’ll focus on the bigger picture instead.

Fig. 1: CT-rendition of the skeletal components of the breast-shoulder apparatus of Anolis baleatus in lateromedial view, depicting all anatomical features described in the text. The gray arrow denotes anterior.

Skeletal elements of the BSA in isolation

Previous analysis of the scapulocoracoid in isolation revealed that its shape differs between Anolis habitat specialists, and resembles a particularly dorsoventrally tall shape in twig anoles (Tinius et al. 2020). The other ecomorph groups (trunk-ground, trunk-crown, and crown-giant) show obvious tendencies towards a particular structural organization, but in none of these does the scapulocoracoid resemble a truly characteristic shape.

SICB 2020: Impacts of a Novel Environment on a Tropical Anole Species

By Laura Taylor

On January 9, 2020

In All Posts

Dan Nicholson at SICB 2020

Evolution has long thought to be a slow process, taking thousands if not millions of years. Recently, there has been a paradigm shift in how scientists think about evolution. We now know that we can observe evolution on a contemporary timescale, observable to the human eye. Dan Nicholson, a Ph.D. Candidate at Queen Mary University of London in Rob Knell’s lab, is working with Mike Logan and others to observe the effects of habitat change on the evolutionary ecology of Anolis apletophallus.

Dan and his team transplanted anoles from the mainland of Panama to several islands around Barro Colorado Island in July of 2017. Before release, they recorded the anoles’ morphological characteristics, including hindlimb and forelimb length, toe pad size, and head depth, and well as characteristics of their perch location, including height and width. Tracking changes in these characteristics can detect natural selection at work. At SICB 2019, Dan reported the results of the first generation of island anoles.

At SICB 2020, Dan included the trends of the second generation of island anoles. The preliminary results indicate the island anoles have continued to use wider perches than the mainland anoles. However, the majority of the island anole morphological traits now align with the mainland anoles. The exception is that hindlimb length of the island anoles decreased, while the mainland anoles hindlimb length has increased.

Some potential causes of these results, Dan speculates, include genetic drift due to the small population size. The islands started with a robust number of anoles, but over the two years of this study, their numbers have rapidly dwindled. Another possibility is the island anoles are aligning with the mainland anoles morphologically due to gene flow. In the future, Dan wants to further analyze the preliminary results from a population angle, looking at changes in groups of traits instead of individual traits.

You can learn more about Dan’s research by following him on twitter.

Sometimes Knights Eat Dragons (Dragonflies, That Is!)

By Chris Thawley

On June 4, 2018

In Introduced Anoles, Natural History Observations

One of the loudest anole meals I’ve witnessed.

During one recent afternoon’s field work, I heard an unusual noise in the botanical garden I was working in: a sound like someone crunching and crinkling a foil potato chip bag. Tracing the sound from about 20 feet away, I did not find a snacking plant enthusiast, but rather a young Knight Anole (Anolis equestris) in survey posture who had apparently just snagged a large dragonfly out of mid-air. The anole chowed down on its prey while keeping a weather eye on me and conducting a few half-hearted displays to let me know it was aware of my presence. As the anole continued to masticate its rather large afternoon meal, it moved to a higher perch away from the prying eyes of this anolologist.

The dragonfly, a Regal Darner (Coryphaeschna ingens), is a common species in the southeastern United States and an accomplished aerial predator. It was also more than a mouthful for this young knight, which had to chew with its mouth open for over four minutes (and still wasn’t finished when it escaped my view); quite the prey handling time! And yet more evidence that this largest of anole species is willing to take a chance on any prey item that might fit into its maw even if it takes a little work.

An impressive snag for such a young anole.

Blanchard Cave, a Window into the Late Pleistocene and Holocene Squamates from Marie-Galante Island (Guadeloupe Archipelago, Lesser Antilles)

By Corentin Bochaton

On November 11, 2015

In All Posts, New Research, Notes from the Field

Over the past few years, two European research programs developed an interest in the ancient fauna and environment of the Guadeloupe islands. The prospection for cave deposits led to the discovery of numerous accumulations of fossil remains documenting the Holocene and Late Pleistocene faunas of the archipelago, especially on the island of Marie-Galante, where three major deposits were discovered.

Blanchard Cave is one of these deposits. This cave contains the oldest fossil-bearing sedimentary layers of the island dated around 40,000 years before present and is an excellent complement to the two others cave documenting the Late Pleistocene fauna of Marie-Galante (Cadet 2 and Cadet 3).

After a test excavation in 2008 that revealed the potential of the site in term of fossil fauna, Blanchard cave was investigated between 2013 and 2014 in the framework of a European research program interested in the past environment and fauna of the Guadeloupe islands, the BIVAAG project. The three excavation campaigns conducted during this period allowed the precise documentation of the sedimentary filling of the cavities and the recovering of thousands of skeletal remains mainly attributed to frogs, lizards, snakes and bats.

The excavation work in the cave (Picture: A. Lenoble)

Welcome gifts from the bats… (Picture: C. Bochaton)

But collecting the fossils remains was not that easy and although the perspective of working in the Caribbean a few hundred meters from the sea could seem very attractive, the working conditions in the cave were far from pleasant. Mainly because the cave was inhabited from the ground to the roof by numerous cockroaches, rats, gnats and bats. Bats were extremely noisy, and proved to be extremely rude hosts. Another difficulty was the potential occurrence of histoplasmosis in the cave that led to the necessity of wearing a respirator during the work. Such masks make breathing difficult during the work and combined with the heat, humidity and other disagreements previously mentioned strongly impact your initial enthusiasm.

Once you overlook these difficulties, the sediment was extracted from the site and then washed and sieved in order to retrieve the small bones contained in it (the bones are usually smaller than 5 mm). The remains were then recovered and sorted, partly in the field (unfortunately this activity often kept the paleontologists outside of the cave and away from the bats), before being studied.

Washing and sieving of the sediments (Picture: M. E. Kemp)

Recovering of the fossil bones (Picture: M. E. Kemp)

The results of the study of the squamates remains collected in the cave can be found in a very recently published paper. To summarize the main findings, we found evidence of the past occurrence of at least ten species of snakes and lizards: four snakes: Antillotyphlops sp., Boa sp., Alsophis cf. antillensis and an undetermined colubroid; and six lizards: Anolis ferreus, Iguana sp., Leiocephalus sp, Thecadactylus sp., cf. Capitellum mariagalantae and Ameiva sp.. The stratigraphic distribution of these taxa in the site combined with previously existing data show that only two extinctions (Boa sp. and Colubroid ind.) are dated from the Pleistocene/Holocene transition and thus predate the arrival of humans on the islands around 5000 years ago. Then during the pre-Columbian times two new taxa appear in the deposits, Iguana and Thecadactylus. On the other hand, a massive faunal turnover began after the European colonization of the island. Indeed, at least six squamate genera (Leiocephalus, Capitellum, Ameiva, Antillotyphlops, Alsophis and Erythrolamprus), including all the snake genera, were extirpated between 1492 and today. Thus, 55% of the squamate genera present during pre-Columbian times went extinct over the past few centuries.

These results are further evidence of the current sixth mass extinction crisis and of the strong impact of humans on this insular fauna. However, Marie-Galante Island remains an isolated case because the past fauna of most of the Lesser Antillean islands remains poorly known and in most cases totally unknown despite the critical importance that such data may have in many fields to test inferences built on modern data.

Postura de Anolis huilae: Communal Nesting!

By DAVID ALFONSO BEJARANO-BONILLA

On March 10, 2015

In Natural History Observations, Notes from the Field

En el marco de mi investigación sobre la Eco-fisiología térmica de Anolis huilae, me encontré (en mi finca) con un par de posturas, una con cuatro huevos y otra con 22 huevos. Este hallazgo me sorprendió, al encontrar diferentes tamaños en los huevos.

Postura de Anolis huilae, Juntas (Ibagué-Tolima-Colombia)

En mi curiosidad por determinar si efectivamente se trataba de huevos de la especie en mención, me di a la tarea de abrir uno para corroborar, encontrando un individuo en un estadío de su formación (el ejemplar fue donado al Laboratorio de Herpetología de la Universida del Tolima).

Embrión de Anolis huilae.

He comenzado hacerle el seguimiento a esa postura, in situ, midiendo y pesando cada uno de los huevos.

Considero que este hallazgo aportará detalles acerca de la historia de vida de Anolis huilae, aún desconocida.

One Night in Antigua – Photos from a Layover with the Colossus Anolis leachii

By Martha Muñoz

On December 7, 2011

In Classics from the Literature, Natural History Observations

Early morning sighting of a female Anolis leachii on a leaf covered in raindrops.

Sometimes, they say, it’s about the journey, not the destination. This makes me think of exciting layovers I’ve had in Anolis country. At any place where the layover is long enough to permit stepping outside of the airport, I like to pop out and see what kind of anoles I can find lurking around the terminals. On a few occasions, travel requires an overnight stay in an exciting place. One of the benefits of working in remote Lesser Antillean islands is that infrequent (and unpredictable) airline schedules typically mean spending a night or two in tiny islands to and from the actual destination. For years I’ve been working in Montserrat, a small island with an active volcano, where I try to follow the flighty bugger Anolis lividus as close to the volcano as I can get. On our way home from Montserrat, we usually spend a night in Antigua, where the charming giant, Anolis leachii can be found.

View of a raincloud and rainbow as we descended into Antigua in January 2009.

Like most anoles from the Lesser Antilles, this species is abundant. However, few species from the Lesser Antilles are as large as A. leachii. It is a member of the bimaculatus clade of large anoles from the Northern Lesser Antilles. According to Scwhartz and Henderson (1991), it can reach a snout-vent length of 123 mm. For anyone who works with crown-giants, this may not seem so large, but for an aficionado of the Lesser Antillean anoles, Anolis leachii is a relative behemoth! Its body ranges from yellow to blue and green, and it’s covered in a purplish vermiculation. The large eyering ranges from a sulfurous yellow to a deep orange. Hands down, this is one of the world’s most beautiful anoles. Imagine my excitement when I got to spend a night chasing these lizards through the wilds of Antigua Village, a cushy beach resort teeming with Anolis leachii and the smaller congener, A. wattsii. Here I offer some photos of this dazzling species, and a bit of its taxonomic history.

Baby Anoles – Cute, Cuddly, and Easily Staged!

By Martha Muñoz

On November 28, 2011

In Research Methods

Check out this piece in the New Scientist, which picked up on our images of Anolis embryos and Thom’s awesome research!

Embryo of Anolis longitibialis, a trunk-ground anole from the Dominican Republic.

The readers of this blog do not need to be convinced that anoles are an amazing model system in evolutionary biology. New and exciting research often finds its way to the Anole Annals. Here we’ve learned about emerging trends in Anolis genomics, speciation, and comparative phylogenetics, to list just a few. In recent years, Anolis has also become a model system for developmental biology. For example, a recent study by Dr. Thom Sanger demonstrated that the diversity of limb dimensions among ecomorphs have evolved from similar developmental mechanisms.

This summer I worked a bit with Thom to learn how to stage Anolis embryos using his handy staging series as a guide. The goal of the project was to determine the stage at which female anoles laid eggs under two treatment conditions – a hot treatment (32°C) and a cold treatment (20°C). I had females from three populations of A. cybotes (55, 700, and 1400 meters in elevation), one population of A. shrevei (2450 m), and one population of A. longitibialis (100m). Unfortunately, I was unable to collect very many eggs despite letting the experiment run for six weeks. I did, however, manage to get several beautiful embryos, which I have imaged and staged. Here I’ll provide some pictures and give a few shorthand methods for staging Anolis embryos.

Dead for a Day – Long Live the Lizard Man, Eric Pianka

By Martha Muñoz

On September 30, 2011

In Anoles and Anolologists in the News

Eric Pianka in the field with Varanus gouldii. Photo: Gisela Kaufmann

Eric Pianka is no stranger to bizarre conversations. As a public figure in evolutionary biology, he has engaged in numerous perplexing discussions with vociferous dissenters from the Creationist and Intelligent Design camps. On September 26, 2011 Eric Pianka received what was possibly the strangest phone call yet from David Hillis, a friend and fellow Professor at the University of Texas, Austin. Hillis informed him that rumor had it that Eric had died. Pianka learned that his obituary had been emailed to the herpetological community through the Center for North American Herpetology (CNAH), in memory of his recent passing. This is certainly not the first instance of bilocation for Eric, whose self-written obituary has been around for over two decades and available on his laboratory webpage for nearly as long. Most readers know that it is a spoof. The heading says so and the obituary ends with “Eric Pianka can be reached at eric.pianka@heaven/hell.com,” but every now and then he gets an uncomfortable email. However, this was the first time that a year of death was added to the obituary and emailed en masse to the thousands of subscribers.

Is An Anole Smarter Than a Fifth Grader?

By Jonathan Losos

On July 13, 2011

In New Research

Manuel Leal and Brian Powell have just published a paper in Biology Letters demonstrating that lizards are smart. Before getting to the details, though—here’s the important point: check out the videos! They’re pretty amazing (here, scroll down and click on the videos).

Here’s the story: working with the Puerto Rican trunk-crown anole, A. evermanni, Leal and Powell presented lizards with an experimental apparatus in their home cages with two wells, in one of which was a dead phoenix worm (whatever that is). Next to the well with the worm was a little round disc similar to a poker chip. The lizards learned to go to the well and find and eat the worms. Then the experimenters placed the chip halfway over the well. Again, no problem.

Now comes the cool part. The experimenters completely covered the well containing the worm with a blue chip. Remember, these are Anolis lizards that usually find their prey by looking for movement—they don’t go digging around in the underbrush. Still, four out of the six lizards figured out how to get the mealworm: two of them bit the chip and removed it from covering the well, while two others figured out how to use their snouts as a lever to flip the chip off the well. This is pure problem-solving, and it uses novel behaviors, rather than simply transferring a natural behavior to a new context! And the two lizards that failed to get the worm came up with their own solution, hitting the center of the chip with their snout—but this was ineffective in dislodging the chip.

Once the lizards had learned to find the worm under the chip, the experimenters then conducted a discrimination trial, giving the choice of a blue chip and a yellow chip. Without error, the lizards always went to the blue chip; subsequently, they were presented a blue chip versus a blue-and-yellow chip, and they still had no problem.

Pretty amazing for a lizard, if you ask me, but it gets even better.

Gear review: the Fish Pen

By Katharina Wollenberg Valero

On May 17, 2011

In Research Methods

“Are you sure you don’t want to take a lizard pole?” – “No way, we’re on vacation, not field work”.

teasing me

But once arrived on the lovely Yucatan Peninsula in Mexico I just couldn’t get any of the anoles perching on about every single palm tree to dewlap for me. I’d speculate about their dewlap colours – they did look like A. sagrei, but how could I be sure without flipping out their dewlap? And if I did, would it be red or orange, and how broad would the yellow margin be?

It was as if they were mocking me with their presence, knowing that I was pole-less. On the next trip to the local supermarket, however, I saw and immediately grabbed a small package that read: “Fish pen, as seen on TV.” It was a tiny telescopic fishing pole, complete with hooks, reel and line, that can clip to your shirt like a pen. For MXP 200 (ca. $20), I just had to buy it. Although I wouldn’t recommend to hunt any large or skittish lizards with it (it’s a short pole), it proved to be quite effective to satisfy any spontaneous dewlap-flipping cravings during vacation.