Anole Annals

As regular readers of this site will know, anoles are remarkable for the repeated, independent evolution of ecomorphs on the four islands of the Greater Antilles. Each ecomorph is defined by a suite of ecological and morphological traits that appear to be shaped by natural selection.

In a recent paper, Kolbe et al. ask whether those suites of morphological traits are actually suites. In other words: is convergence in form across islands reached by evolving the same sets of characters in a similar manner? Do all trunk-ground ecomorphs, for example, achieve relatively long limbs by growing both the femur and the humerus (i.e. those traits covary together)? Or do some trunk-ground anoles achieve long limbs by only growing the tibia and the radius while others grow the femur and radius etc.?

Covariance ellipses for 8 species for five trait sets. Find the ellipse for Anolis distichus in the first column. It suggests that A. distichus will have a short humerus when it has a short femur and a long humerus when it has a long femur and this covariance is fairly tight (an oblong ellipse). For lamella# and femur length, however, there isn’t a tight relationship (a circular ellipse) and it’s hard to predict lamella# from femur length. Note the similar shape of the covariance ellipses for the three trunk-ground anoles, A. gundlachi, A. sagrei, and A. cybotes. These suggest convergent evolution of trait sets in that ecomorph.

Understanding whether and how different sets of traits vary together can give a good understanding of how natural selection and evolutionary history combine to explain the convergent evolution of Anolis ecomorphs.

The authors ask several questions in this paper.

Parasites Regained

By Travis Ingram

On July 16, 2012

In Natural History Observations

A few weeks ago, we collected the common grass-bush anole Anolis pulchellus around the El Verde Field Station for an enclosure experiment looking at interspecific interactions. We stored the lizards in baggies in the lab for a day or two, moved them to their enclosures for just under three weeks, and we’ve recently finished recapturing them from the enclosures. After measuring their growth and sampling their diets, we put them back where we found them so they could continue on their way with a great story to tell their friends.

One unlucky anole, however, never made it to its enclosure. When I retrieved its bag to take to the experiment site I found the following tragic scene:

Evolution Meeting 2012: Mystery Anole Sighted

By Yoel Stuart

On July 15, 2012

In Natural History Observations, New Research

Early specimens and scientific drawings of Anolis proboscis

At the Evolution 2012 meeting, after a scheduling snafu delayed his talk fifteen minutes and prompted panic from an anticipatory audience, Jonathan Losos mused about the natural history and ecology of the Ecuadorian Horned Anole, Anolis proboscis. In case you missed his talk, read all about the rediscovery of A. proboscis.

Following the talk, an audience member reported seeing a horned anole during fieldwork in the Guiana Shield. She attempted to catch it, but it eluded her. From her description, it sounded like A. phyllorhinus, but A. phyllorhinus has only been reported in the Brazilian Amazon. A. proboscis is Ecuadorian and the third known proboscid anole, A. laevis, is from the Peruvian Amazon.

At the very least, this suggests a range extension for A. phyllorhinus. Or, there could be a new species of proboscid anole waiting to be described in the Guiana Shield! Has anyone else seen this anole?

MIGUEL TREFAUT RODRIGUES, VINICIUS XAVIER, GABRIEL SKUK, AND DANTE PAVAN. (2002) NEW SPECIMENS OF ANOLIS PHYLLORHINUS (SQUAMATA, POLYCHROTIDAE): THE FIRST FEMALE OF THE SPECIES AND OF PROBOSCID ANOLES. PAPEIS AVULSOS DE ZOOLOGICA, S. PAULO: 42, 363-380.

JONATHAN B. LOSOS, MELISSA L. WOOLLEY, D. LUKE MAHLER, OMAR TORRES-CARVAJAL, KRISTEN E. CRANDELL, ERIC W. SCHAAD, ANDREA E. NARVAÉZ, & , FERNANDO AYALA-VARELA, AND ANTHONY HERREL (2012). NOTES ON THE NATURAL HISTORY OF THE LITTLE-KNOWN ECUADORIAN HORNED ANOLE, ANOLIS PROBOSCIS Breviora, 531 DOI: 10.3099/531.1

Anoles, And Other Herpetofauna, Of Mindo, Ecuador

By Jonathan Losos

On July 14, 2012

In Natural History Observations

Anolis fraseri. Photo by pbertner.

We recently had a post on the rediscovery of the horned anole of Ecuador, Anolis proboscis, which is found only in the environs of Mindo, Ecuador. Mindo is a lovely spot whose economy is strongly focused on ecotourism, but in a very rustic, old school way, making it a delightful place to visit, even more so because of its anoles. The horned anole, of course, is the star, but there are several others there as well, such as the crown-giant A. fraseri and the incredibly common A. gemmosus, which can be found sleeping in high numbers, yet is hard to find during the day.

A sleeping gem. Photo by Jonathan Losos

The Tropical Herpetology website has a series of pages on the reptiles and amphibians of Mindo, which includes a list of all species as well as specific pages on some of the species, including A. proboscis, A. fraseri, and A. gemmosus. The site also has wonderful photographs. This is not the first post on the Tropical Herpetology website–we covered their pages on the species at Chical, near the Ecuador-Colombia border, last October. It’s a great site.

Lizards Can’t Take The Heat – But Can They Take The Cold?

By Martha Muñoz

On July 13, 2012

In Natural History Observations

You might think this picture was taken in New Hampshire, but these are the pine forests of Valle Nuevo National Park, where Anolis shrevei is found

There are many chilling realities associated with global warming. One of the major lines of research in climate change is to understand how organisms will respond to increasing temperatures. Ectotherms such as reptiles are excellent model systems for learning how organisms will be affected by climate warming as their performance (running, jumping, etc.) is so tightly linked to temperature. Research by Ray Huey and colleagues, for example, has shown that increasing temperatures is pushing some lizards to their thermal limits, leading scientists to suggest that some lizards might not be able to take the increase in heat that is expected over the next few decades.

But spending three years working at high elevation in the Dominican Republic has made me wonder a different question – Can lizards take the cold? Beginning around 1,700 meters or so in the DR you begin to enter a strange habitat. At these high elevations the habitat is composed of pine forests that are reminiscent of New Hampshire, and require that you remind yourself that you are, indeed, still in the Caribbean. It is cold up there – near Valle Nuevo in the Eastern Mountains and near Loma de Toro in the Western Mountains the mean winter temperature hovers just above freezing. Even in summer the nights are cold and the crepuscular hours tangibly chilly.

Here’s Something You Don’t See Every Day

By Jonathan Losos

On July 13, 2012

In All Posts

From Nathan Watson’s instagram page.

Evolution Meetings 2012: Ecomorphology of Mainland Dactyloa Anoles

By Rich Glor

On July 13, 2012

In New Research

The first poster session at Evolution 2012 got off to a great start last weekend with Rosario Castañeda’s poster on ecomorphological evolution in mainland Anolis. Currently a post-doc in the Losos Lab at Harvard, where she’s working to bring Anolis to the Encylopedia of Life, Rosario’s Ph.D. thesis with Kevin de Queiroz and associated publication investigated phylogenetics and ecomorphological diversification of the Dactyloa clade of Anolis. For those who aren’t already familiar with the Dactyloa clade, this group of impressive anoles can be found in the Lesser Antilles and South America. In her poster, Rosario presents results obtained by combining her multi-locus phylogeny with morphometric data.

Using UPGMA analyses of principal component axes extracted from morphological measurements of 50 species of Dactyloa and 28 species from the Greater Antilles, Rosario initially reported recovering nine distinct morphological clusters (four of which include only one species). Rosario further reported that these phenotypic clusters do not correspond with monophyletic groups on her phylogenetic tree, suggesting that each cluster did not simply evolve a single time. Finally, Rosario used distances among species in morphometric space to show that fifteen species in the Dactyloa clade are similar to one of the replicated Greater Antillean anole ecomorphs. She specifically reported that species from the Dactyloa clade can be assigned to trunk-crown, trunk-ground, and twig ecomorphs.

Anoles in Paris

By Natalie

On July 12, 2012

In All Posts

I’m spending the summer in Paris, and while the city of lights has much to offer, I assumed two months here meant two months away from my beloved anoles. As it turns out, this is not the case! Even though anoles are New World lizards, there are still Anolis moments to be had here. In the Jardin des Plantes, the zoo and natural history complex of Paris, I was excited to find an Anolis equestris in the herpetarium. I took a picture of the sign below the cage:

Also, on an admittedly un-anolis-related note, but one of herpetological relevance: in the chateaux of the Loire Valley, the most common animal featured in the coat of arms of old royal families (and therefore throughout the architecture of their palaces) is the salamander. Evidently, in the past, salamanders were believed to breathe fire and were widely popular as symbols of power. I’ve included only a couple of many examples of salamanders below:

Maybe the anole community could popularize our favorite genus in a similar way?

Evolution Meeting 2012: Rapid Character Displacement In Green Anoles

By Jonathan Losos

On July 11, 2012

In New Research

The Evolution meetings are now ended, but the fond memories linger on. Such as Yoel Stuart reporting the results of his study of character displacement in Mosquito Lagoon, Florida. Dredge spoil islands were created about 50 years ago when the area was dredged, producing big piles of sand which were subsequently colonized by plants and, eventually, green anoles. Within the last 10 years, many islands were invaded by brown anoles, but some remained sagrei free. Yoel set out to compare the green anoles on islands with and without brown anoles.

First, though, he demonstrated the islands with and without brown anoles didn’t differ consistently in any environmental parameter. Thus, nature has set up a very good experiment.

Yoel found that green anoles perch higher in the presence of brown anoles, presumably a result of interspecific interactions. Moreover, on brown anole islands, green anoles have better developed toepads. A common garden experiment reveals that these differences are not the result of plasticity. Hence, morphological differences have evolved in a very short time as a result of a habitat shift caused by the presence of another species–an excellent example or rapid evolutionary change and character displacement in action.

Anole Poetry

By Kevin de Queiroz

On July 11, 2012

In Anole Art, Literature, and Humor

While filing old reprints, I came across a paper of unknown provenance by John M. Burns (Emeritus entomologist at the National Museum of Natural History) titled “Poems from the Natural History Seminar” containing poems that Burns composed to introduce speakers in the Wednesday noon seminars at the Museum of Comparative Zoology in the early 1970s. One of them is relevant to anolologists and was used to introduce Robert Trivers, who presented a seminar on sexual selection in Jamaican Anolis lizards (8 December 1971):

Trivia for Trivers

The male of an anole named garmani / Is subject to sexual selection. / He seeks an existence of harmony / And the chances to make a connection.
To do this he must defend holdings / (Which are plots for becoming attractive) / By resorting to dewlap unfoldings, / Being robust, and generally active.
He must be a competitive wizard, / Yet succeed in enticing a friend / Who will mate him. But being a lizard, / He does it by halves in the end.

If you enjoy biology-inspired poetry, Burns is also author of the book BioGraffiti (1981, W. W. Norton & Co.).