What a lovely festive (a.k.a., brown) anole!

For more on the new AMNH exhibit on Cuba, see our previous report.

h/t to Sandra Buckner for notifying us of this magazine cover.

It’s been a while since we updated this montage…and at least a few months since the last anole cover. Get to work, everyone! And let me know if we’ve missed any.

Peter Uetz of the Reptile Database fame sends the following Valentine’s Day greetings:

If you or your significant other loves anoles, you may want to show her/him this hearty Anolis distichus (Figure 2960, above) on occasion of today’s Valentine’s Day. It clearly shows a heart on it’s head. Some other specimens such as the couple in Figure 3297 (right, from locality 1 in the Google map), also show a heart although it’s not as pronounced. Also note their blunt coloration which doesn’t seem to affect their affection.

Anolis distichus is pretty variable and even within this subspecies, A. d. dominicensis Reinhardt & Lütken 1863, to which all these specimen belong, there is considerable variation. By the way, the guy with the heart (Figure 2960) is from the same locality 3 as two other specimens which do not have a heart (Figures 2948 and 2968) although they display a similar shape on their heads. Figure 3087 shows yet another specimen for comparison, this time from locality 2.

2968

2948

3087

Various authors have described a dozen subspecies from Hispaniola (reviewed in Schwartz 1971, see map 2 from that paper). The northern half of Hispaniola is almost entirely in the hands of A. d. dominicensis, hence the specimens on the photos have been assigned to that subspecies.

Note that Glor & Laport 2012 elevated several Dominican subspecies of A. distichus to full species level, namely A. dominicensis, A. favillarum, A. ignigularis, A. properus, and A. ravitergum. The Reptile Database hasn’t followed this yet because their geographic sampling was limited to relatively few localities and they did not provide any updated diagnoses (but their recommendations have been recorded in the database). Also, there seems to be hybridization among several of these populations.

Photo localities:

2948: 3

2960: 3

2968: 3

3087: 2

3297: 1

Acknowledgments

Thanks to Miguel Landestoy and Luke Mahler who helped with the IDs.

References

Glor, Richard E.; Robert G. Laport 2012. Are subspecies of Anolis lizards that differ in dewlap color and pattern also genetically distinct? A mitochondrial analysis. Molecular Phylogenetics and Evolution 64 (2): 255-260.   http://www.sciencedirect.com/science/article/pii/S1055790310004276

Schwartz, A. 1968. Geographic variation in Anolis distichus Cope (Lacertilia, Iguanidae) in the Bahama Islands and Hispaniola. Bull. Mus. comp. Zool. Harvard 137 (2): 255- 309.  http://biodiversitylibrary.org/page/4784182

Schwartz, A. 1971. Anolis distichus. Catalogue of American Amphibians and Reptiles (108)

(used to be available online at ZenScientist, and maybe soon at the SSAR website again).

Anolis distichus in the Reptile Database

http://reptile-database.reptarium.cz//species?genus=Anolis&species=distichus

(an extended synonymy and distribution section will appear in the next database release)

The database entry also has another 43 references most of which are available online.

Any congress advertising with a horned anole (Anolis proboscis) must be worth attending. Check out the details at the conference website.

A new paper in Zootaxa aims to figure it out, based on the travel journals of its describer, Franz Werner. Here’s the paper’s abstract:

The eminent Austrian zoologist Franz Werner described several new species of amphibians and reptiles from America, including Anolis aequatorialis Werner, 1894 and Hylodes appendiculatus Werner, 1894. Both species were described based on single specimens, with no more specific type localities than “Ecuador” (Werner 1894a,b). After its description, A. aequatorialis remained unreported until Peters (1967) and Fitch et al. (1976) published information on its distribution and natural history. Anolis aequatorialis is currently known to inhabit low montane and cloud forest on the western slopes of the Andes from extreme southern Colombia to central Ecuador, between 1300 and 2300 m elevation (Ayala-Varela & Velasco 2010; Ayala-Varela et al. 2014; Lynch et al. 2014; D.F. Cisneros-Heredia pers. obs.). Likewise, Hylodes appendiculatus (now Pristimantis appendiculatus) remained only known from its type description until Lynch (1971) and Miyata (1980) provided certain localities and information on its natural history. Pristimantis appendiculatus is currently known to occur in low montane, cloud, and high montane forests on the western slopes of the Andes from extreme southern Colombia to northern Ecuador between 1460 and 2800 m elevation (Lynch 1971; Miyata 1980; Lynch & Burrowes 1990; Lynch & Duellman 1997; Frost 2016). To this date, the type localities of both species remain obscure. The purpose of this paper is to restrict the type localities of Hylodes appendiculatus Werner, 1894 and Anolis aequatorialis Werner, 1894 based on analyses of the travel journals of their original collector.

Day’s Edge Productions has produced a great new video about how two species with seemingly identical dewlaps manage to coexist. Manuel Leal explains what’s really going on.

This video originally appeared in bioGraphic, an online magazine from the California Academy of Sciences that features beautiful and surprising stories about nature and sustainability. 

What is bioGraphic, you ask? Here’s what it’s webpage says:

A multimedia magazine powered by the California Academy of Sciences, bioGraphic was created to showcase both the wonder of nature and the most promising approaches to sustaining life on Earth. We hope our stories will spark conversations, shift perspectives, and inspire new ideas, helping not only to shed new light on our planet’s most pressing environmental challenges, but also—ultimately—to solve them.

Through an ever-evolving array of storytelling tools and techniques, we will introduce you to some of the world’s most intriguing creatures and inspiring people. We’ll also transport you to faraway places, enabling you to experience what it’s like to be there and what’s at stake for those involved. Along the way, we’ll take a critical look at the environmental issues that pose the greatest threats to our future—and the most promising ideas for addressing them.

So please come along—and come back often—as we travel the globe in search of stories that inspire both awe and hope for a more sustainable future.

Kristin Winchell talks about her studies on urban anole evolution on an interview on PRI.

I’ve recently learned that famous nature micro-photographer Piotr Naskrecki observed an aquatic anole catching prey underwater. Here’s what he had to say on his blog, The Smaller Majority:

The other aquatic iguana

Buy ’em here, use this code: WINTERTREATS

• • The Scientist »
  • January 2017 Issue »
  • Notebook

Caribbean Anoles Function as Model Organisms for Evolutionary Dynamics

The small lizards adapted to unique niches among dozens of isles.

By Amber Dance | January 1, 2017

316

NOTICE ME!: A male Anolis stratulus (barred anole) extending his dewlap in Puerto RicoPHOTO BY MICHELE JOHNSON

It’s not easy to snare a lizard. Evolutionary biologist Michele Johnson affixes a noose made of dental floss to a telescopic fishing rod to reach into the bushes and tree canopies where Caribbean anoles live. By the end of the summer field season, her students from Trinity University in San Antonio, Texas, develop a knack for it. “We almost always catch our lizards,” says Johnson.

She doesn’t just collect field measurements and observations; she’s taken 30 different species of anoles back to her lab to analyze their physiology. Anoles have become a favorite model for evolutionary biologists because of their extraordinary diversity—there are more than 400 species in genus Anolis—and because of how they originally populated the Caribbean islands. The relative scarcity of mammals, snakes, or birds on the islands left many niches open for the lizards to occupy.

As anoles—which also inhabit Central and South America—reached individual islands, their populations diversified into island-specific forms that occupy certain niches. For example, each of the four largest islands in the Greater Antilles (Hispaniola, Cuba, Puerto Rico, and Jamaica) hosts one or more species that are green lizards hanging out in the lower canopies of trees, and another group of short-limbed, slow-moving reptiles that perch on twigs. These are two of the six “ecomorphs” that scientists who study Caribbean anole species have defined. To be considered an ecomorph, a set of habitat specialists must exist on more than one island, though the species in each group differ between islands. And yet, other anole species belong to no particular ecomorph class.

Caribbean anoles offer scientists a sort of “natural experiment,” explains Luke Mahler, an evolutionary biologist and herpetologist at the University of Toronto. Each isle, with similar environments, acts as a replicate for how anoles underwent convergent evolution into ecomorphs. As a result, evolutionary studies of anoles have flourished in the past couple of decades—think Darwin’s finches, but scalier.

“They really are a good model system for lots of questions, from very small-scale molecular work all the way up to adaptive radiation,” says Jerry Husak, a physiologist at the University of St. Thomas in St. Paul, Minnesota.

The basic anole ecomorphs go way back in evolutionary history, found Jonathan Losos, an evolutionary ecologist at Harvard University. Emma Sherratt, now at Australian National University in Canberra, got a hold of 20 fossil anoles while a postdoc in Losos’s lab. The fossils dated back 15 million to 20 million years, when the lizards were preserved in amber on the island of Hispaniola. Some were in museums, others in private collections. Using CT scans, the Losos team examined anatomy to confidently assign these fossils to four of today’s ecomorphs; a couple other fossils might be part of a fifth (PNAS, 112:9961-66, 2015). “At least several of the habitat specialist types already existed,” concludes Losos.

Despite the countless hours biologists have spent studying Caribbean anoles, the genus seems to have plenty of surprises still in store. In addition to her ongoing studies of physiology and behavior in diverse anole species, Johnson has recently focused on how her local Texan anole, Anolis carolinensis, determines dominance. A. carolinensis, like many other anole species, adopts a strict mating hierarchy in captivity, with males battling each other for access to prime habitat and to females. In the field, the hierarchy is more complicated—a lizard defending his own territory is more likely to win a fight, she thinks. She figured the biggest males would also be more likely to triumph, either in the lab or the field, and thus achieve larger territory and more females to court.

In order to correlate body characteristics and behaviors with dominance, Johnson’s group set up a sort of lizard fight club, pitting anoles against each other in one-on-one cage matches, with a single perch to battle over. Winners tended to execute more visual displays, performing push-ups and head-bobs and expanding the showy throat skin known as a dewlap. They also chased and bit the losers, who tended to back away and to hide in a corner.

But larger anoles weren’t always the winners in captivity or in the field. “Body size doesn’t predict who wins these fights at all,” says Johnson. Instead, behaviors made a huge difference—the most aggressive lizards won their matches. A longer head also helped, perhaps because it looked to opponents like a serious biting weapon. In the field, animals with a wider head and powerful jaws occupied larger territories with more females present (Anim Behav, 118:65-74, 2016).

Body size still probably matters, Johnson says. She has not yet tested in field studies whether size might help an A. carolinensis male establish his territory or take over a vacated area. And at least in other anole species, bigger males sire more offspring.

Mahler also got a surprise from the anoles when, in 2010, he received an email from Miguel Landestoy, a Dominican naturalist who claimed he’d seen a new species. Mahler was initially skeptical. “Everybody thinks they’ve got a new species,” he says, yet “the Caribbean anoles are the best known anoles, by a long shot.”

Then Mahler opened Landestoy’s pictures. “Holy crap,” he said. “That doesn’t look like anything we’ve seen on Hispaniola.” The critter was huge, by anole standards—about a foot from nose to tail tip. It had short legs, a short tail, and a mottled greenish-gray pattern that suggested it could easily blend into a mossy or lichen-covered branch. “I bought the first cheap flight I could find,” recalls Mahler.

The other thing that struck Mahler about the new species—which he and his colleagues dubbed A. landestoyi—was that it looked similar to anoles found in Cuba. Their clade is called chamaeleonides for their creeping, chameleon-like movements and camouflage prowess. These particular kinds of anoles, scientists had assumed, were unique to Cuba. But here was another species, making its living in many of the same ways, on Hispaniola (Am Nat, 188:357-64, 2016). “This is an example of what might be a seventh ecomorph. . . . Evolution is more predictable than we have yet given it credit for,” says Johnson, who was not involved in the project.

“It’s amazing, in part, that anything new there could be found after all these years,” adds Losos, a coauthor on the study. “The age of discovery is not yet over.”