from the front page of the South Florida Sun Sentinel, above the fold!

Evolutionary biologist James Stroud holds a crested anole caught by his mini lasso on an island at Fairchild Tropical Botanic Gardens in Coral Gables. Scientists are studying how the brown anole from Cuba and the crested anole from Puerto Rico compete with one another and drive each species to adapt and find slightly different niches in the ecosystem. (Joe Cavaretta/South Florida Sun Sentinel)

By Bill Kearney | South Florida Sun Sentinel

PUBLISHED: November 30, 2024 at 7:00 AM EST

 

CORAL GABLES — Fairchild Tropical Botanic Garden may look serene at first glance, but beneath the resplendent orchids and majestic banyans, two invasive lizards are waging a turf war.

The war started a few years ago when Cuban brown anoles, who have called South Florida home for about 100 years, came face to face for the first time with a new rival: crested anoles from Puerto Rico.

As the two species, which look almost identical and occupy the same ecological niche, faced off, biologists were able to document who was winning, and more importantly, how quickly the losers were adapting to survive on new turf.

A new study reveals that the losing species is adapting at a rapid pace, changing their behavior, but also their bodies. This fast adaptation is altering what we know about how evolution works.

Nearly identical invaders

Brown and crested anoles are almost identical — lanky, 4 to 8 inches long, splotchy brown and skittish (lots of animals eat them). But the cresteds are slightly bigger, and the males grow a crest on their tails.

Both lizards evolved on separate Caribbean islands to perch on tree trunks where they can scan the forest floor dart into leaf little to snag meals such as spiders and roaches.

But they’ve never had to compete against each other. “They’re convergently evolved,” said Georgia Tech evolutionary biologist James Stroud, who led the team of researchers on the study.

“They evolved completely independently. … Their last common ancestor is probably around 60 million years ago. To put that in perspective, humans and chimps, their last common ancestor was 13 to 16 million years ago. So the lizards are deeply deeply diverged.”

Stroud said that in 2018, crested anoles showed up at Fairchild Tropical Botanic Garden, where he’d already been studying survival rates and evolutionary adaptation of the brown anoles.

The arrival provided Stroud and his team the opportunity to study, in real time, how quickly species can adapt under pressure.

They used a fishing pole with a tiny lasso on the end to catch every lizard on an island at Fairchild the size of a football field. They then measured their physical traits, tagged them with ID numbers, released them exactly where they caught them, and spent months observing them. They then recaptured the survivors several months later.

“What we saw was when they came into contact, the cresteds, which are a little bit bigger, can dominate behaviorally, so they pushed the browns to the ground,” said Stroud. In other words, the crested anoles won the turf war, and the browns moved to a more dangerous place with a lousy view.

The territory change showed behavioral elasticity, but Stroud was also interested in physical adaptation. His team found that over time, brown anoles with longer legs had higher survival rates after the crested anoles showed up.

Researchers also tested the finding at other lizard hot spots around South Florida. They discovered that wherever brown and crested anoles had to compete for territory, the browns became more land-based, and those with longer legs lived longer. If there were no crested anoles present, long legs did not correlate with better survival.

“Before the cresteds arrived, when the browns were not living on the ground much, leg length didn’t really matter to survival,” Stroud said. “But as soon as the crested anoles arrived, brown anoles with relatively longer legs survived better. … Now that brown anoles have shifted where they’re living — suddenly there’s an adaptive benefit to having longer legs.”

Stroud suspects that the longer legs helped the browns run faster to escape predators such as herons, egrets, mocking birds and larger invasive brown basilisk lizards from Central America.

From that survival rate, he and other evolutionary biologists can gain a clearer understanding of how natural selection, and thus evolution, is operating in the world.

“This is called microevolutionary dynamics,” Stroud said. Over the past 40 or 50 years, evolutionary biologists have begun to realize that evolution might actually happen quickly enough to record in something as short as a 10-year field study. “We never thought it was possible,” Stroud said.

This bucks against one of main tenants of Charles Darwin’s theory of evolution, that evolution happens very, very slowly over time.

Darwin’s notion of slow evolution made sense at the time, Stroud said. Some fossil records don’t change at all for 50 million years. “Slow gradual change through the fossil records was the evidence Darwin used to think that evolution moved at a really, really slow pace,” Stroud said.

But Stroud’s lizards in this study, as well as previous ones, show rapid changes almost constantly. Anoles live short, fast lives. Males rarely survive longer than a year, and females sometimes eke out two years of life. And they’re constantly laying eggs.

Their generations compile quickly compared to humans and other large mammals. “We think these sorts of evolutionary dynamics play out in all organisms, it just changes relative to the organism’s life history,” Stroud said.

If brown anoles at Fairchild evolve to have longer legs, that doesn’t mean they’ll change the species globally. These blips in traits can fade. But if the pressure is right, if natural selection is strong and widespread, “it can lead to rapid evolutionary change,” Stroud said.

The Lizard Olympics

Stroud isn’t done with South Florida’s invasive lizards. He’s currently conducting a study that he’s dubbed the “Lizard Olympics.”

This past spring, he and the team tested the hundreds of lizards they’ve caught on the island for various physical skills. They tested their speed on a race track; they tested their bite strength with a highly sensitive bite meter; and they tested their grip strength by placing them on leaves and bark surfaces and pulling them off.

They then tagged them and let them go on the island, and will later recapture them to see if those skills correlate to better survival for different species.

Stroud said they’ve already inferred longer legs mean faster speed and thus better survival for brown anoles, but now they’re testing it directly.

He anticipates that each species will have different skill-survival correlations: running speed might be irrelevant to the tree-dwelling green anoles, but grip strength might be important, while brown anoles might need more speed.

The lizards are being put to the test, but so are the researchers. “My students are hating me, because we just finished processing 2.5 thousand slo-mo videos of lizards running.”

Quick localized evolution, and what it means for the bigger picture of a species, is something Stroud and his peers are trying to understand — how these micro events fit into the macro story of a species.

“We now know that evolution can happen on really rapid evolutionary time scales, but what does that mean for the creation of new species?”

South Florida, with its menagerie of invasive species, gives them a unique opportunity to cast a bit more light on the mystery.

Collecting reptile names is one thing, but it’s a different thing to figure out what these names actually mean. At the Reptile Database we have collected the etymologies of more than 11,000 reptile species, but there are still a lot of gaps for subspecies and synonyms. I wonder if anyone in the Anole community is interested in that subject.

More specifically, there are 434 species of anoles with a total of 109 subspecies (excluding nominate subspecies), that is, a total of 543 names. Of those, we do have the etymologies of over 500 taxa, but there are at least 32 missing (all Caribbean subspecies). Here is the list:

• Anolis allogus BARBOUR & RAMSDEN 1919
• Anolis confusus ESTRADA & GARRIDO 1991
• Anolis homolechis (COPE 1864)
• Anolis loysiana (COCTEAU 1836)
• Anolis lucius DUMÉRIL & BIBRON 1837

In addition, we need the etymology of the following subspecies:

The technology-minded among you may say, sure, that’s easy, just ask ChatGPT what these names mean. Here is what ChatGPT says about the first 3 of them:

• Anolis equestris potior:
  • potior: Latin for “better,” “superior,” or “more important.” This could suggest that this subspecies is seen as a more distinctive or notable form compared to others.
• Anolis strahmi abditus:
  • abditus: Latin for “hidden” or “concealed.” This might indicate a subspecies that is difficult to find, perhaps due to a cryptic lifestyle or remote habitat.
• Anolis lineatopus ahenobarbus:
  • ahenobarbus: Latin for “bronze-bearded” (ahenus meaning “bronze” and barba meaning “beard”). This likely refers to a feature such as a bronze or reddish coloration on the chin or throat.

You can see that ChatGPT has a pretty good grasp of Latin, and it can make good educated guesses, but it is often not quite sure about the finer details behind species names.

When it comes to eponyms, it’s much worse. Here is an example for some of the eponyms of Pholidoscelis auberi (apologies, not an anole, but a Caribbean Teiid with currently 39 subspecies, of which at least 10 are eponyms, so it’s a good example). Let’s take a look at these 10, namely

• Pholidoscelis auberi auberi (COCTEAU 1838)
• Pholidoscelis auberi garridoi (SCHWARTZ 1970)
• Pholidoscelis auberi granti (SCHWARTZ 1970)
• Pholidoscelis auberi hardyi (SCHWARTZ 1970)
• Pholidoscelis auberi kingi (MCCOY 1970)
• Pholidoscelis auberi orlandoi (SCHWARTZ & MCCOY 1975)
• Pholidoscelis auberi paulsoni (SCHWARTZ in SCHWARTZ & MCCOY 1970)
• Pholidoscelis auberi richmondi (MCCOY in SCHWARTZ & MCCOY 1970)
• Pholidoscelis auberi schwartzi (GALI & GARRIDO 1987)
• Pholidoscelis auberi zugi (SCHWARTZ in SCHWARTZ & MCCOY 1970)

Here is what ChatGPT says:

1. auberi: Named after Paul Aubert, a naturalist or explorer, as many species are named in honor of individuals. It was first described by Jean Theodore Cocteau in 1838, hence the name Pholidoscelis auberi auberi.
2. garridoi: Likely named after a person with the surname Garrido, honoring their contribution to science.
3. orlandoi: Likely named after an individual named Orlando, possibly in honor of a person or place associated with the subspecies’ discovery or description.

I save you the remaining ones, because you get the gist: ChatGPT has no idea who these people are, including the namesake of P. a. auberi, which  was not named after Paul Aubert, as ChatGPT claims, but rather after Pedro Alejandro Auber (1786-1843), a Cuban botanist and naturalist of French origin (née Pierre Alexandre Auber). The only eponym ChatGPT got right was Pholidoscelis auberi schwartzi, named after Albert Schwartz (1923-1992), the doyen of Caribbean herpetology — one out of ten. Ouch!

So, if you are interested in etymology, of Anolis or otherwise, please let me know. As said, we have about 100o reptile names in need of clarification.

Thanks 🙂

Anolis heterodermus. Photo from iNaturalist by Andres Florez.

Although anoles are much more well studied and understood in the Caribbean and United States, there is a decent amount of diversity of these lizards throughout South America as well. In consultation with Jonathan Losos, I have agreed to write a series of posts outlining the South American diversity (parts 1 and 2), invasives (part 3), and conservation (part 4) of these animals. This post (diversity part 1) will describe the species that occur in the regions of South America north and west of the Andes along the Caribbean and Pacific Coasts, respectively, while diversity part 2 will focus on the Amazon and everything south and east of the Amazon.

In case you don’t know me, I had experience as a graduate student studying lizard functional morphology of toes and tails in North, Central, and South America. More recently, I have become way too involved in identifying lizards on iNaturalist.org, with a focus on lizards of the New World. To satisfy my own particular obsessiveness, I have tried to identify every lizard observed in the Amazon (all 300+ species of them!) and have expanded those lizard-identifying efforts into other areas as well. It was these efforts that gave me the idea that perhaps the AnoleAnnals might be interested in what I’ve noticed from this relatively understudied part of the world. As such, I will draw liberally from data available on iNaturalist to illustrate my points.

Anole diversity along Caribbean and Pacific Coasts

As of this writing, there are currently nearly 12,000 observations on iNaturalist of 102 species Anolis in South America (“research grade” observations filtered by “wild” and “has photos”). Compare this to the 238,000 observations of 270 species from North America (on iNat this region includes all of Central America, Mexico, the United States, and the Caribbean). Only eight of the species of South American anoles are introduced non-native species (more on this in part 3). This suggests that there are nearly 100 species of Anolis endemic to South America. Clearly, the anoles from South America are not as diverse and not as well observed as those from other areas.

Anoles along the Pacific Coast range from southern Ecuador (and perhaps northern Peru, but not well documented) north to the junction with Central America and continue along the Caribbean Coast east to the mouth of the Orinoco River in Venezuela (note: according to iNaturalist, Guyana, Suriname, and French Guiana are part of the Amazon region even though they may not be part of the Amazon watershed). This region is separated from the Amazon by the Andes Mountains and Orinoco River and very few species cross these particular barriers. Hence, many of the anoles of northern South America still have some degree of endemism and it is this endemism (and the resulting beta diversity) that I highlight below. Keep in mind that new species are being described on a regular basis, so the list below is almost certainly incomplete, but still illustrates my general point.

The species of Anolis that occur in north and west of the Andes include (organized by their geographic distribution):

Western (non-Amazonian) Ecuador (n=9)

A. bionotatus, A. bitectus, A. fasciatus, A. festae, A. lyra, A. neomonteae, A. parilis, A. peraccae, A. proboscis

Western (non-Amazonian) Colombia (n=18)

A. anchicayae, A. antioquiae, A. antonii, A. calimae, A. danieli, A. eulaemus, A. gorgonae, A. heterodermus, A. maculigula, A. macrolepis, A. mariarum, A. medemi, A. quimbaya, A. solitarius, A. sulcifrons, A. tolimensis, A. urraoi, A. ventrimaculatus

Western Ecuador/Colombia (n=13)

A. aequatorialis, A. anchicayae, A. chloris, A. dracula, A. fraseri, A. gemmosus, A. gracilipes, A. granuliceps, A. limon, A. lynchi, A. maculiventris, A. parvauritus, A. princeps

Northern Colombia/Venezuela (n=3)

A. jacare, A. onca, A. tetarii

Northern Venezuela (n=4)

A. anatoloros, A. annectans, A. squamulatus, A. tigrinus

Aruba, Bonaire, and/or Curaçao (A-B-C islands) (n=2)

A. bonairensis, A. lineatus

Found in western Colombia as well as crossing the Darién Gap into Central America (n=8)

A. biporcatus, A. gaigei, A. latifrons, A. poecilopus, A. purpurescens, A. triumphalis, A. tropidogaster, A. vittigerus

Along Caribbean Coast as well as crossing into the Amazon (n=2)

A. auratus, A. planiceps

Non-native anoles (n=8)

A. aeneus, A. cristatellus, A. marmoratus, A. porcatus, A. richardii, A. sagrei, A. trinitatis, A. wattsii

Several things become apparent when considering the above diversity.

—First, there are roughly 67 species of anoles that occur north of the Amazon. Given that there are only about 102 anole species that occur in all of South America, perhaps 2/3 occur in the area adjacent to the speciose Caribbean. That leaves only 1/3 of the South American anole species occurring south and east of the Andes Mountains.

—Second, of the 67 anole species found north of the Amazon, 47 species (70%) are endemic to this region of mainland South America, two species (3%) are endemic to the A-B-C islands, eight species (12%) cross from mainland South America into Central America, and two species (3%) are found extensively in the Amazon as well. So, not as diverse as North America, but with outstanding regional endemism. This regional endemism translates into an impressive beta diversity with geographic replacement probably the rule rather than the exception. In other words, when travelling from one valley to the next, species replacement (beta diversity) occurs at a relatively high rate so that nearly an entirely different set of species may be present in adjacent areas, depending on the nature of the barrier between them. Making this even more of a challenge, in some instances the barrier appears to be the low-lying valley instead of a mountain ridge. For example, in Colombia, Anolis heterodermus Duméril 1851 was recently split into eight distinct species (Morena-Arias et al. 2023). Both the various mountain ranges (Cordillera) as well as the Magdalena River valley appear to act as barriers isolating the various lineages into distinct species. Hence, in terms of trying to identify the Anolis in some of these areas, accurate geographic location is a must.

—Third, there are only eight species (12%) of non-native anoles in all of South America (including the A-B-C islands and Trinidad and Tobago). All eight occur in northern South America and only one or two (A. porcatus and perhaps A. sagrei) occur elsewhere in South America. Contrast this with the 16 or so species of introduced anoles in North America, which have made extensive inroads in places like the southeastern United States, southern Mexico, and certain of the Caribbean Islands. These eight introduced species will be the focus on part 3 of this series.

One of the interesting things about the high degree of endemism of the anoles of northern South America is how quickly it probably occurred. Andean orogeny began perhaps 20 million years ago (mya) and lasted until about 8 mya. Hence, the diversity differences between the occidental (western) and oriental (eastern) regions of countries such as Ecuador, Colombia, and Venezuela are notable for their near completeness. For comparison, the Laramide orogeny that created the Rocky Mountains occurred between 80-55 mya; the Alleghanian orogeny that created the Appalachian Mountains occurred between 325-260 mya. Hence, the temporal arrival of the Andes created spatial barriers to gene flow and geographic complexity that is reflected in the high beta diversity of Anolis both within and between regions of South America.

In conclusion, northern South America is the diversity hotspot for anoles. The anole species north of the Amazon are dominated by native, highly endemic species that often have geographic ranges limited to a single country, a single valley, or even one slope of a single mountain ridge. Moreover, there are relatively few introduced anoles in South America with most of those introduced to the A-B-C islands and Trinidad and Tobago. Given that almost no species of anoles cross the Orinoco River or Andes Mountains and very few species occur extensively in the Carribean or Central America, the anoles of northern South America represent a fairly separate and distinct fauna when compared to other geographic regions within the distribution of Anolis.

Literature cited:

Moreno-Arias, R. A., Méndez-Galeano, M. A., Beltrán, I., & Vargas-Ramírez, M. 2023. Revealing anole diversity in the highlands of the Northern Andes: New and resurrected species of the Anolis heterodermus species group. Vertebrate Zoology, 73, 161-188

Hello fellow anole enthusiasts!

I’m reaching out because I’m in need of some specific anole photos for my research. I’m currently wrapping up my dissertation on the diversification of the Anolis carolinensis subgroup, and I would like to include head profile photos of male anoles in their light phase with the dewlap fully extended (see figure).

I’m specifically looking for images of the following species:

Anolis brunneus

Anolis carolinensis

Anolis longiceps

Anolis maynardi

Anolis smaragdinus

If you have high-quality photos of any of these species, I would greatly appreciate your contribution. All photos will be fully credited to their respective authors, and I’d be happy to share a PDF copy of the published article once it’s completed. Please contact me at javiertorres@ku.edu.

Thank you in advance for your support!

Best regards,

Javier

Photographs by Odey Martínez Llanes

Read all about it!

Photograph by Odey Martínez Llanes

Photo by Julie Katz

Hard to imagine a more important service than this! Miami resident Julie Katz provides the details: “When I walked out of my condo building one night this past spring to walk my dog I encountered a first – a small lizard feasting on a roach.”

Go anoles!

Anolis porcatus (left) found at a plant nursery in Aruba (right).

It was late December 2018. My partner in work and life, Matt, and I were headed back to Curaçao to conduct some follow-up sampling. We had recently completed a field season in Curaçao where we had discovered three newly introduced gecko species (Behm et al. 2019).  Since we had to fly through Aruba to get to Curaçao, we decided when booking our trip to spend some time in Aruba, too, to look around for introduced herps, since that’s one of our favorite ways to spend our time when traveling (we’ve even been known to trick family members into searching for introduced herps while on vacation – e.g., Behm et al. 2018). Aruba and Curaçao are neighbors and since Aruba is even more economically connected than Curaçao, we suspected there may have been undiscovered non-native herps there.

What we did not expect was that in less than 3 days on Aruba, we would find three new non-native species (Anolis gingivinus, A. cristatellus and Hemidactylus frenatus) and document a range expansion for a 4^th non-native anole (A. porcatus) already known to be on Aruba (Behm et al. 2022). Even though we focused our surveys on properties like plant nurseries and resorts that had a strong likelihood of harboring introduced species due to their influx of ornamental plant shipments, this was still a very high number of species in a short amount of time.

I wanted to understand how these newly documented species fit within the context of the other non-native herps on Aruba. Specifically, I wanted to understand the circumstances surrounding the initial introductions and the current habitat use of the species on Aruba to assess whether any emergent patterns could be gleaned for Aruba. If so, these patterns may lend further insight into how and why the Caribbean has emerged as a hotspot for species invasions (e.g., Helmus et al. 2014, Perella and Behm 2020, Gleditsch et al. 2023).

What seemed like a simple task ended up being more challenging than expected due to the scant and sometimes contradictory information in the literature surrounding the species introductions. To make sense of it all, I enlisted the help of a brilliant undergraduate in my lab, Gianna Busala, whose tenacity and attention-to-detail made it possible to reconstruct some of the invasion history on Aruba.  Our recent publication (Busala et al. 2024) compiles all of what we found about the introduced herps on Aruba.

In conducting our research, there were several issues we encountered.

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Photo by Christa Denning (aka, @DenningDesign)

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