Author: Jonathan Losos Page 107 of 133

Professor of Biology and Director of the Living Earth Collaborative at Washington University in Saint Louis. 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 Museum Has The Most Anoles?

By Jonathan Losos

On March 27, 2012

In Anole Annals Trivia

Rich Glor recently put up a fascinating post on the enormous number of Anolis specimens deposited in the natural history museum at the University of Kansas, which got me thinking: which natural history museums house the most anole specimens? I’ve got the answer (you can, too, if you go to Herpnet, but what fun is that?): Who can name the top five? One caveat: apparently the holdings from the University of Michigan Museum of Zoology are not available. I supplemented my studies by going to the British Museum’s website, and I think all the other major players are on Herpnet, though would welcome news to the contrary.

So, here’s a bit of information, a hint of sorts: the leading institution has nearly twice as many specimens as the second place depository, which in turn has more than half again as many as the third, which is barely ahead of the fourth and the fifth.

And here’s something else: very few museums have any specimens registered under the generic name Norops. I’m not saying that the proposal to split Anolis into multiple genera is dead (see here), but clearly it didn’t get a lot of traction in the museum world. Oddly, though, one of the bastion’s of anti-Norops sentiment, the Museum of Comparative Zoology, has 75 Norops. We’ll have to see how long that stands.

Any way, have at it. Top 5: Which are they?

Mystery Lizard: It’s Sitana!

By Jonathan Losos

On March 24, 2012

In Anole Annals Trivia

No flies on you guys. I put up a mystery “lizard”—note: not “anole”—with a beautiful white dewlap and the trademark diamondback pattern of a female anole, but few were fooled and it was quickly identified as the southeast Asian agamid lizard, Sitana ponticeriana. The dead giveaway—if you want to be technical—is the presence of only four toes on the hindfoot.

This species—or very possibly a complex of species—shows remarkable geographic variability in dewlap color. See the gorgeous red, black and blue one here. They’re even said to change color seasonally, from blue to white, but I’m not sure how well-established that is.

This photograph comes from J.N. Trivedi’s fascinating 2010 Master’s Dissertation entitled “Study of courtship behaviour of Fan – throated lizard Sitana ponticeriana in scrublands of Vadodara city Gujarat.”

Enormous Dewlaps, Mainland-Style

By Jonathan Losos

On March 23, 2012

In Natural History Observations

Anolis chloris. Photo by Luke Mahler

A recent post extolled the size of the dewlap of the Hispaniolan A. christophei, but a number of readers, myself included, suggested that to find a truly humongous dewlap, you need to go to the mainland. And all one needs to do is look at the wondrous A. chloris pictured above to see that that is true. I challenge any Anole Annals reader to show me a photo of a Caribbean anole strutting his stuff so gynormously.

Still don’t believe me? Here are a few more.

Left to right, top row: unidentified Central American anole (ID, anyone?) from http://rhamphotheca.tumblr.com/post/1322893581/male-anolis-lizard-displaying-dewlap; A. polylepis from http://en.wikipedia.org/wiki/File:Anolis_polylepis,_Costa_Rica.JPG Steven J. Johnson; bottom row: A. gemmosus from James Christensen's spectacular flicker site, http://www.flickr.com/people/primevalnature/; unidentified anole from http://www.morley-read.com/frogs_on_line/telimbela/lizards/source/dscn8660.html; and A. frenatus also from Christensen's flickr site.

As far as I’m aware, no one has conducted a quantitative study to compare dewlap sizes among mainland and Caribbean anoles. Sounds like a good project for someone!

More importantly, though, why do the largest dewlaps occur on the mainland? Perhaps it has something to do with the relatively low population densities and low rates of display of mainland anoles? Another project waiting to be conducted.

What Species Is It?

By Jonathan Losos

On March 20, 2012

In Natural History Observations

Female (on left) and male (on right). Tough one. Good luck. Check back for a hint in a few days if no one nails it.

Veragua Rainforest: An Anole Mecca

By Jonathan Losos

On March 18, 2012

In Notes from the Field

One of the many frogs at the Veragua Rainforest preserve. The frog diversity is so great, it almost rivals the anoles in interest. Photo from http://veraguarainforest.com/research/imagenes/overview_small.jpg

Fresh from our four day foray at La Selva, our class of intrepid herpetologists moved east to the Veragua Rainforest Research & Adventure Park. Take one glance at their website, and you’d think this is some tacky tourist trap. But you’d be wrong. Only four years old, this multi-purpose venue is a wonderful place for biodiversitistas of any sort. Admittedly, a bit too touristy at first glance—the place is a regular stop for cruise ship passengers to take a break from playing online slots at casinos in Colorado at EasyMobileCasino.com and to disembark for the day at the port city of Limon. The facility has excellent educational displays with wonderful live collections of frogs (in the Ranario), reptiles (Reptilio), butterflies and other insects. Not to mention the ziplines, which we were duty bound to use in our quest to locate canopy dwelling lizards (one probable A. lemurinus was cited approximately 25 meters high on a tree trunk).

But Veragua is much more than a fun place to stop-over.

More Cristatellus Adventures in Costa Rica

By Jonathan Losos

On March 17, 2012

In Notes from the Field

Brown basilisk. Photo from http://www.naturephoto-cz.com/photos/sevcik/brown-basilisk--_DSC9899.jpg

A little more than a year ago, this correspondent trekked to the eastern coast of Costa Rica to chronicle the spread of the invasive Puerto Rican anole, A. cristatellus. Introduced to the Caribbean port city of Limon many moons ago, we found that the crested anole has made its way down the coast to the vicinity of the Panamanian border, and speculated that it may also have crossed the bridge to the Land of the Canal. In addition, it has spread inland to the west, as far and as high as the town of Turrialba and, at lower elevations, to Siquirres, 60 km from Limon. However, 37 km further west, we failed to find it in Guapiles, though our visit was late in the day. Given its widespread occurrence at low-to-mid elevations, we predicted that the Puerto Ricans may some day advance far to the north and west, trampling through the Tortuguero area to Nicaragua and who knows how far westward?

Taking advantage of our herpetology class sojourn to Costa Rica, I led an intrepid expedition comprised of a freshman, a sophomore, and a graduate student to head eastward from the La Selva Biological Station to determine just how far these lizards have advanced.

Anoles As A Model System To Study Reproductive Biology

By Jonathan Losos

On March 14, 2012

In New Research

Anolis carolinensis mating. Photo by Michele Johnson from Wade (2012). Insets: Upper, vertebral column of green anole around pelvis and tail; lower, hemipenis musculature.

Juli Wade has just published a review paper in which she sings the praises of anoles as a group to study the integration of behavior, anatomy, endocrinology and molecular mechanisms in vertebrate reproduction. She notes that a number of model systems exhibit, but synthesis is hindered because courtship and copulatory systems have been studied in different groups and, among studies of courtship biology, very disparate structures have been examined (e.g., bird syrinxes, frog larynxes, fish swim bladders) making comparative analysis difficult.

Anoles to the rescue! Wade notes: “Anoles offer some advantages over these other model systems. A long history of research into the hormones, brain and behavior exists for one species, the green anole (Anolis carolinensis), and a substantial amount of data is also available for the brown anole (A. sagrei). These studies indicate that the hormonal regulation of behavior appears quite similar in these two species of anoles. The genome of the green anole has recently been sequenced, which greatly facilitates investigations at the molecular level. Two features, however, provide unique power for the investigation of mechanisms regulating structure and function.

First, three sexually dimorphic systems exist within the same individuals – portions of the limbic forebrain, which control higher level or more motivational aspects of sexual behavior, and both courtship and copulatory neuromuscular systems, all of which lend themselves to investigations in the field and laboratory. Second, more than 350 species of anole lizards span the Southeastern US, Caribbean islands and Central and South America. Information on the behavioral ecology and phylogenetic history of many of these is accessible. And, while limited data on the neural and muscular structures regulating courtship and copulation are currently available, it is clear that species across the genus exhibit beautiful variation in the degree of sexual dimorphism in morphology on a gross level. Anole lizards therefore represent a terrific opportunity for more detailed investigations from an evolutionary perspective.”

La Selva Lucky Seven

By Jonathan Losos

On March 13, 2012

In Notes from the Field

Anolis carpenteri. Photo from http://ctaudubon.blogspot.com/2011/04/young-researchers-shine-during-costa_05.html

We notched the double anole hat trick in the most unexpected manner last night, as a female of that rarely seen species, A. carpenteri, presented itself sleeping at chest level on an isolated plant in the clearing. With a day yet to go, hope springs eternal that a resplendent green A. biporcatus will make it a lucky seven at La Selva.

News flash—breakfast! Just learned that last night, the team headed for a ditch filled with caimans found an A. biporcatus sleeping on a branch above the trail. Seven anole species in two days!

Seven anole species at one site (eight if we include the unseen A. pentaprion). Certainly, a lot of anole diversity, but not unheard of in any way. In fact, such diversity occurs regularly on the Cuba, Hispaniola, and Puerto. Yet, the anole ensemble here differs greatly from what we would see in a diverse Caribbean community. All species-rich assemblages in the Caribbean are extremely similar, composed primarily of the different ecomorph types. Usually, such a location would have very common trunk-ground and trunk-crown anoles, and then representatives of three or all four of the remaining ecomorph types. The remaining species would either be some of the “unique” habitat specialist types which occur only on one island, such as the rock wall specialist A.bartschi on Cuba or members of the Chamaelolis clade; or they would include multiple members of the same ecomorph type, such as several trunk-ground anoles that use different thermal microhabitats.

By contrast, the La Selva Eight bears little similarity to these assemblages.

5 Anole Morning At La Selva

By Jonathan Losos

On March 11, 2012

In Natural History Observations

Anolis capito, the pug-nosed anole. Photo by Greg Mayer from http://whyevolutionistrue.wordpress.com/2009/08/23/summer-reading-and-summer-vacation-anoles/

What better way to start off a spring break herpetology class field trip than to go anole hunting? And what a success it was! There has been concern in recent years that the herpetofauna at the fabled La Selva Biological Station in Costa Rica has been declining, but we found no shortage of herps this morning–helped, no doubt, by ample rain yesterday. Anolis humilis and A. limifrons were extremely abundant, as were strawberry poison arrow frogs and, surprisingly, night lizards. A number of A. lemurinus, beautiful red dewlap and all, were spotted, and at a stream, a trio of aquatic anoles, A. oxylophus. The highlight of the morning, however, was finding a female A. capito in its traditional spot half a meter up a tree trunk. The pug-nosed anole, as it is called, is always cryptic, and seems to have become less common in recent years, but this is our second in 24 hours, as another was found during a night walk last night.

And that was just the morning. Going for the double hat trick today, all eyes will be out for the emerald green A. biporcatus. It’s very overcast, which may work against us finding this sun-loving crown dweller often seen high in trees on sunny days. Of course, the Holy Grail of La Selva anolology is A. pentaprion, the twig anole rumored to frequent narrow branches in the canopy, and very rarely seen. But with 26 pairs of herpetological eyes on the lookout, who knows what’s possible?

Oldie But Goodie: Anolis on the Cover of National Geographic

By Jonathan Losos

On March 10, 2012

In All Posts

Lot of talk on this site about the deserved prevalence of anoles on the cover of major periodicals (most recently here). I thought it might be useful to remember what I consider to be the greatest anole cover of all time. The answer, incidentally, is “no.” And the species? Anolis garmani from Jamaica.