Anole Annals

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?

Crowdsourcing Anole Dewlap Photos

By Travis Ingram

On March 11, 2012

In All Posts, New Research

I come to you, anologists of the world, with a request for your photos of anole dewlaps. I’m planning a study of dewlap size evolution across the Anolis phylogeny, but there’s not much data available for many of the less common species. I know many anole-hunters take pictures of their quarry with dewlaps extended after catching them, so I thought I’d try to extract data (e.g. dewlap length and area) from a collection of photos. If you have photos you might be able to share, please read on, and feel free to contact me if you have questions.

Requirements:

-The photo should show a live, adult male caught in the wild. Its dewlap should be fully extended – ideally either of its own volition or with tweezers, but fingers are ok as long as at least 90% of the dewlap area is visible.

-The anole’s entire head should be in the photo (so I can scale dewlap size relative to head size). If there’s a ruler or object of known length in the photo that’s even better.

-The photo should be close to a side-view profile (give or take no more than about 10 degrees angle in any direction).

-At a minimum, identify the species and the approximate location (country or island). Please do include any extra information you can share (e.g. date, latitude/longitude/altitude, snout-vent length of anole, weather…), but I know this may not be available for all the photos.

Clearly I’m new to this – any photo better than this one should be useable.
Check out the comments section of this post for some better examples.

If you have one or more suitable photos you can contribute, please send them to me as an attachment to an e-mail. If you have large files or many photos (more than ~5MB) that may not make it through e-mail servers, drop me a line and I’ll send you a link to a Dropbox folder instead. If you are willing to give permission to use the photo (with full credit, of course) in potential blog posts, web pages (e.g. Encyclopedia of Life entries), or publications, please say so in the e-mail; otherwise I will only use the photos to extract basic measurements.

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.

On Sexual Selection in Anolis

By Yoel Stuart

On March 9, 2012

In Classics from the Literature, Natural History Observations

"Fig. 33. Sitana minor. Male, with the gular pouch expanded (from Gunther's 'Reptiles of India')."

In The Descent of Man and Selection in Relation to Sex (1871), Darwin laid out his ideas about sexual selection. Darwin believed that sexual selection was distinct from natural selection; while natural selection operates through survival and fecundity, sexual selection operates through differences in mating success among individuals.

The puzzle that Darwin set out to solve was the existence of traits like the peacock’s tale or the elk’s antlers. These traits differ between sexes but aren’t related directly to mating. And, these traits appear to be quite costly. Darwin reasoned that these costly traits must benefit the bearer in some way related to mating success. Most likely, these benefits accrued during battle with other members of same sex for mates or during the courtship of the opposite sex. In both cases, having the costly trait benefitted an individual’s mating success beyond the incurred survival or fecundity cost.

Now, how does this discussion relate to anoles?

Film on the Yasuni Region of Ecuador

By Alex Gunderson

On March 8, 2012

In Notes from the Field

Hello anolers. A friend of mine named Ryan Killackey is making a documentary film about the Yasuni region of Ecuador, home to indigenous tribes and incredible biodiversity (including anoles!). The region is also, not surprisingly, under pressure for development and the film is documenting that struggle.

More On The Sad Anole Merchandise Situation

By Jonathan Losos

On March 8, 2012

In Anoles in Commerce

A year ago, AA lamented that in Costa Rica, land full of wonderful anoles, there was scarcely an anole piece of merchandise for the anole-entranced ecotourist to purchase. More recently, we commented that not only was the same true in the Dominican Republic, another bastion of anolishness, but that tourist marts were full of merchandise sporting green iguanas, an invasive species in that country.

On my recent trip to Aruba and Curaçao in quest of A. lineatus, I took time out to survey the lizard merchandise situation. Intrepidly venturing into one souvenir shop after another, powering through crowded stalls in outdoor crafts marts, I comprehensively surveyed the supply of schlock, tchotke and junk. It wasn’t easy, but I got through it all. And the result is clear: despite their prehistoric ugliness, green iguanas are all the rage.

Iguanas out of control in the ABC Islands.

Do Anoles Produce Ultrasonic Hissing Noises?

By alexiss

On March 7, 2012

In Anole Annals Trivia

It has recently come to my attention that several websites (e.g. wikipedia) report that male anoles produce ultrasonic hisses while fighting. I’ve been trying to track down the source of this information, but I can’t find any reference to ultrasonic sound production in anoles in the scientific literature. Does anyone know the source of this information? Can anyone confirm that anoles are capable of producing ultrasonic sounds? I’d be grateful to anyone who can shed any light on this rumor.