Good morning, Mr. Anole. Please get off my car.
Tweeted by Sugar Glitzcream from JenMang‘s Instagram photo.
Year: 2012 Page 7 of 47
Anolis cristatellus from Puerto Rico. Photo taken by Liam Revell
Anolis lizards are a model system for studies of evolutionary ecology because they are remarkably adaptable creatures. We know from long-term studies conducted by Jonathan Losos, Dave Spiller, Tom Schoener, and others that anoles can rapidly adapt their behavior and morphology over ecological timescales. For example, the presence of a ground-dwelling predator (Leiocephalus carinatus) forged a strong selective gradient in favor of A. sagrei with longer hindlimbs within a single generation. Interestingly, in a follow-up study the long-term effect of this predator is that A. sagrei evolves shorter hindlimbs, as they will tend to perch higher off the ground, where the perch diameter is narrower than near the ground. These studies of rapid morphological evolution puts anoles in the a very exclusive club with the likes of stickleback fishes, Peromyscus beach mice, guppies from Trinidad, Galapagos finches, and few others, as vertebrate systems in which evolutionary change on ecological timescales has been confidently demonstrated.
A notable exception to Anolis ‘evolvability,’ however, is thermal physiology. The thermal physiology of reptiles is generally evolutionarily conserved – taxa separated by millions of years and found in very different thermal environments will often share similar physiological patterns. But recent research has suggested that some physiological metrics may not be as static as previously thought, and that Anolis invasions provide an excellent opportunity to see how labile physiology actually is.
Three stereotyped head-bobbing patterns of A. carolinensis. The black area represents the amplitude of the head as it moves up and down. Although amplitude can vary within and among individuals, the cadence remains constant for each of the display types. The hatched area refers to times when the dewlap is displayed. Length and number of dewlap displays and associated headbobs at the end of the display can be quite variable. This figure is a modification from Jenssen et al. (2000) that appeared in Lizards in an Evolutionary Tree.
Anole displays have proven to be as frustrating as they are fascinating. These displays, which are species-specific and typically involve headbobs and/or pushups that may or may not be accompanied by dewlap extensions, are as varied as one might expect within a group as diverse as Anolis. However, despite concerted efforts by an energetic group of researchers aimed at understanding the form, context and meaning of these varied adult male displays, a complete understanding of this complex signal eludes us. The stereotyped displays exhibited by many anole species are of particular interest, and of these, arguably the best-studied are the A, B, and C displays of that lab rat of the anole world, Anolis carolinensis.
In a recent paper, Jenssen and collaborators report a characteristically detailed and rigorous field study on the use of such stereotyped displays in both breeding and postbreeding free-ranging A. carolinensis males. Through painstaking analysis of videotapes of thousands of undirected male displays in nature with no obvious receiver, they show, among other results, that breeding males in “monitor” mode (i.e. lizards that signal while stationary) used mostly C displays, but increased use of A and B displays while moving or “travelling.” Monitoring lizards also exhibited an overall lower display rate than travelling males, and used more and longer volleys of displays. Additionally, about a third of all displays had an extra “shudderbob” tacked on. These patterns held through the postbreeding season. Interestingly, Jenssen et al. note that these undirected displays aimed at no-one in particular are most similar to aggressive signals used by males engaged in contests. The implication is that these undirected displays are in fact directed at an unidentified (or undetected) rival male audience, rather than being for the benefit of any single lady lizards in the area.
The notion of males displaying aggressively just in case any rivals might be present makes sense for a species such as A. carolinensis that defends areas harbouring females, rather than trying to attract them. One wonders if this result would hold for species that place less emphasis on territory defense and that have been rumoured in the past to exhibit signs of female preferences (Anolis valencienni, anyone?).
You voted for the photos, now get the calendar featuring fabulous photographs of 12 anole species taken by eight different anole photographers. A great stocking stuffer! On sale today at Zazzle.com. A share of all proceeds go to a worthy cause–specifically, buying calendars for next year’s photo contest winners.
Annual conferences are a major way for scientists to get their research out to a broad audience and to find out what is new and emerging in different fields. For those of us who study Anolis lizards, there are two annual conferences that are a major draw for our community – the Society for Integrative and Comparative Biology (SICB) meeting in January and the SSE/SSB Evolution meeting in June. There are other conferences, as well, that meet less often, such as the World Congress of Herpetology and the Anolis Symposium, which are also important gatherings for our growing community.
Last year, we were pleased to report that Anolis research was prominently featured throughout the SICB conference in Charleston, South Carolina. In addition to more than a dozen talks and posters, there was also an open forum on the Anolis genome and evo-devo research, in light of the publication of the A. carolinensis genome. The online schedule for SICB 2013 has just been published and a preliminary search using the keyword Anolis returns a list of 18 talks and posters. There is a great diversity of topics explored this year, including phylogenetic frameworks for evolutionary convergence, aggressive behavior, locomotion, thermal ecology, and parasitism, among others.
One of the cool things we did last year was blog live from SICB in Charleston (1, 2, 3). Because the conference was hosted in South Carolina, Marc Tollis shared some pictures of actual anoles at the conference center. We plan to blog live from the conference in San Francisco and provide you with information about all the interesting research being done on anoles. Stay tuned for more!
Anolis bartschi photograph by Steven De Decker.
[Editor’s Note: the person who took this photograph is Steven De Decker; see comments after the first paragraph for corrected information]
As one of the seven or eight folks who judged the photos in this year’s AA photo contest I want to give some recognition to an image that didn’t even make the list of finalists determined by popular vote. My judge’s choice award winner is a striking photograph of a juvenile of the Cuban endemic Anolis bartschi that was taken by Joe Burgess at Cueva del Indio, Vinales, Cuba. Although observed most frequently on rocks in karstic regions, individuals like this one are also commonly seen on trunks and other broad perches emerging from the karst beneath. The quality and clarity of this image are superb. The subtle colors along the animals spine and the steely blue of the eye and surrounding region are beautiful under natural light (perhaps complemented with a tactfully subtle fill flash?). A catch-light in the black eye gives the lizard some personality, and makes me wonder what it might be thinking. The right front forelimb is lifted off the trunk and possibility somewhat blurred by motion, impressing me with the animals agility and suggesting that its ready to make a move. This photo that makes me want to get out and find some anoles.
[Note from Jonathan Losos: I screwed up! There were two photos of A. bartschi entered into the photo contest, and when Rich asked for information on the A. bartschi photo, I gave him the info for the wrong one. The photo above was taken by Steven De Decker (who also took the grand prize winning photograph of A. allisoni). Steven had this to say about the photograph of the juvenile: “It was in the proximity of the prehistoric wall at Vinales, Pinar Del Rio. We were there with 2 local biologists who told us A. bartschi was pretty common to be found at the wall 10 years ago. Great was our disappointment when we saw that [the curly tailed lizard] Leiocephalus carinatus had taken over habitat near the wall. When we went back we decided to investigate some semi caves at the border of the park, and that’s where we found A. bartschi sitting on a trunk near the caves. And to answer your question, no I didn’t use a flash for this particular photo. Using the flash here would have given me a black background.
Meanwhile, below I’ve pasted the photo of A. bartschi by Joe Burgess (whose photo of an A. gorgonae took second place in the contest); this is the photo for which Rich gave info in his post above.
Phylogenetic comparative methods whiz Liam Revell has developed a new method to visualize character evolution of continuous traits on a phylogeny. The program is cool and worth checking out on his Phytools blog, but the important point is that he illustrates the method by reconstructing size evolution in Greater Antillean anoles.
Good luck!
Get it today–framed prints, greetings cards, what a great holiday gift!
Could this be the all-time coolest anole dewlap?
As we all know, even though the diversity of anoles is greater on mainland Central and South America, we know a lot more about the island species. This extends even to simple matters such as resources for learning about and identifying species–for many mainland areas, it is hard to get information on the species that occur there, although this has changed in recent years.
Nowhere is this more true than in Mexico, an anologically rich area for which information on the anolifauna has not been brought together into a single compendium. Into this breach step Levi Gray, Steve Poe, and Adrian Nieto Montes de Oca, who have just produced a photo guide to the anoles of Mexico.
They recognize 46 species of Mexican anoles. Of these 46, the authors and collaborators in the Poe Lab have caught 40 of them, including approximately 21 from their type localities, and field work this month is targetting three of the others. The photos in the key are all from the authors, except the carolinensis photo provided by Alexis Harrison. The key includes all Mexican anoles that the authors recognize (leaving out forms they consider unlikely to be valid–e.g., cumingi–or that have questionable status–e.g., utowanae). The authors report that the well-known species schmidti, simmonsi, breedlovei, polyrhachis, microlepis and adleri are junior synonyms of other forms; these points will be discussed in a paper currently in review in Zootaxa; unfamiliar names in the key (e.g., rubiginosus) will be explained in that paper as well.
Below are low-resolution pictures of the guides; larger, downloadable pdfs can be accessed here. And I can’t help but adding: isn’t the diversity of dewlap colors and patterns incredible? I vote for sericeus as one of the greatest ever!
