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Hello again from North Charleston!
We started off strong: this morning’s “Sexual Selection in Herps” session was dominated by anole talks. Bieke Vanhooydonck, from the University of Antwerp, discussed sexual dimorphism and dewlap growth in Anolis baracoae. By repeatedly measuring individuals over the course of their development into adulthood, Vanhooydonck observed a number of morphological changes. All the observed morphological characteristics showed no significant difference between males and females, with only the key exception of dewlap size. Male dewlaps were found to be larger. The development of dewlaps in the genders diverges, and the male dewlaps subsequently outgrow the female dewlaps, when lizards reach sexual maturity. An interesting and unexpected discovery made by this study was the significant decrease in male dewlap size that occurs with old age. Vanhooydonck proposed that this might be caused by loss of elasticity in skin.
Following her was Michele Johnson of Trinity University, who discussed the interplay of natural and sexual selection in Anolis sagrei and Anolis maynardi. She hypothesized that the difference in head shapes for male and female Anolis lizards may be driven by diet, male-male competition, or female choice. Looking to the particularly elongated head of A. maynardi, Michele explored the potential function implications of extreme head shape. Actively foraging A. maynardi lizards appeared to move more than “sit-and-wait strategists” A. sagrei. In A. maynardi dominance trials, Michele found that the winner of male-male territorial competitions is most commonly the male with the shorter snout (and therefore increased bite force). However, in female choice trials it was observed that females most frequently chose the male with the longer snout. Although she noted her findings are still preliminary, this leaves us with an intriguing question: if the selective forces from male competition and female choice are counteracting one another, what will ultimately determine snout length in A. maynardi populations?
A bit later, Martha Muñoz (ñote: with regard to the ñame-tag failure, it is really ñot that hard to type ñ. C’mon SICB) presented her research on behavioral and physiological adaptations to the thermal environment in the Hispaniolan cybotes group. The diverse species of lizard in this group occupy a broad range of elevation, habitat composition, and thermal environment. If Anolis lizards are not using behavior to mitigate extreme temperatures in their habitat, we might anticipate changes in physiology. No differences were observed between the study species preferred or mean field body temperatures, which implies that they are actively and purposefully thermoregulating. However, she explained that there are limits to behavioral control. What if there was no access to shade for reprieve from the heat? Or what if it was too cold to bask? From her data, Martha suggests that the cybotoids are able to evade extreme heat, but an inability to avoid extreme cold in some environments has made it advantageous to adapt a physiological tolerance to the cold.
The poster session was dotted with Anolis research as well, including such topics as A. carolinensis satellite cells and tissue regeneration. Ellie Cook, who I met while she was working with Michele Johnson in the Dominican Republic this summer, had a great poster displaying her analysis of the affect of parasitism on dewlap coloration in Anolis brevirostris. Her data show that whiter, duller dewlaps are correlated with greater ectoparasite loads. She suggests this may the result of cartenoids being diverted during parasite-instigated immune response.
This has been a fantastic first conference experience for me! I am really sorry to be leaving so soon. I have been super impressed by the Anole community’s contributions to SICB – please keep updating, guys!
There’s more than just anole biologists congregating at the SICB 2012 meeting.
To say it’s been cold here in Charleston, SC would be an understatement. Tuesday night, after the conference tipped off, it was 25 degrees Fahrenheit. But today, the temperature picked up a bit and moved into the 50s. Since we know they don’t hibernate in the winter months, I thought it might be possible that the local anoles may take advantage of the sunny afternoon to do a little basking. Just as the poster session was underway at about 3pm, I decided to give it a shot and take a look around what would be prime Anolis carolinensis habitat in the spring and summer: the bushes and a brick wall around the pool.
Sure enough, I spotted one male and two females right away! I texted Bryan Falk immediately, and we set to flexing our off-season collecting muscles. Doing a quick tour around the conference center, we managed to observe 6 and catch 3. No anoles were injured during this brief collecting trip – perhaps only mildly perturbed 🙂
We spotted a female on a sun-drenched black lamp post. Nice warm spot on an otherwise cool day.
Here's a sweet lady I snatched from a vine-laden verandah at the back of the conference center.
Bryan Falk with female green anole. Note the winter plumage on the human.
As 2011 winds down, it’s time to look back and recall what made this such a wonderful anole year. With this in mind, Anole Annals presents in 2011 Top 5 List:
#5: The Dominican Republic:
Lots of good research and data came out of the D.R. this year, including landmark studies on the green anoles, the A. distichus complex and anole malaria, not to mention many successful field trips and spectacular photos.
#4: Evolutionary Relationships of the Giant Mainland Anoles
Anolis princeps, a large member of the Dactyloa clade. Photo by Jonathan Losos
The phylogeny of the Dactyloa clade of primarily South American anole species, including the largest continental anoles, has long defied resolution. But no longer. In a beautifully worked out integration of morphological and molecular, Castañeda and de Queiroz provided a well-resolved evolutionary tree, which revealed many unexpected insights into the biogeography and evolution of these fabulous species.
#3: New Species
As is customary at year’s end, Anole Annals looks back on a banner year. 396 posts (and counting); 111,432 page loads; 64,843 visits. And what better time to reminisce about our finest moments? So, let’s vote for Post of the Year. Below are the six most viewed posts. Vote for one, or suggest your own in the Comments section.
A Highly Anecdotal Account of a Most Remarkable Anole
Dead for a Day – Long Live the Lizard Man, Eric Pianka
How the Green Anole Was Selected To Be The First Reptile Genome Sequenced
Is An Anole Smarter Than a Fifth Grader?
Society for the Study of Evolution Announces Changes to the Name of Its Journal
Congratulations to Neil Losin for winning the second round of our header photo contest with his image of A. sagrei from South Miami. In an effort to be inclusive, I’ve included the top six photographers from each of the first two rounds in the final vote. Ramon E. Martínez-Grimaldo’s image in the first round slaughtered the competition with 136 votes (the next highest vote getter had 26 votes); will his image of A. isthmicus take home the grand prize?
This is the second round of voting for the best Anole Annals header photo. As reported previously, the winner will receive a signed copy of Lizards in an Evolutionary Tree. On the strength of dozens of votes from visitors arriving at our page from Mexico via Facebook , Ramon E. Martínez-Grimaldo’s photograph of A. isthmicus was the landslide winner of the first round. Congratulations Ramon! Next week we’ll have a final vote involving the top vote-getters to determine the winner.
As Jonathan describes in Lizards in an Evolutionary Tree (Chapter 8 ) data on anole food preferences are sparse. However, this is a critical element of anole biology that needs to be more thoroughly explored if we are going to understand the diversity of skull shapes (the topic of a future post), nutrition, or energetics in anoles. The question is simple in principle but difficult in practice: do species preferentially eat certain insects? If so, has head shape adapted for the preferential capture or mastication of insects of a particular size or hardness? Do lizards that eat insects of lower “quality” eat more often or move less often? Perhaps anoles will eat what ever bug it happens to encounter and skull diversity is the result of other selection pressures. At this time we do not yet know. Interestingly, however, preliminary evidence suggests that the primary food source of many anoles are just ants, which while quite abundant are not very nutritious. Ants can account for up to 80% of the stomach contents of A. distichus for example.
The embedded video gave me an idea for a great experiment that can be done in a controlled setting. Simply run various bugs across the screen of an iPad and see if different species preferentially target particular sizes or shapes. If anyone would like to donate an iPad to this cause of utmost importance I would be happy to perform the experiments.
Our Anole Annals header photo contest has elicited some rather spectacular entries. Narrowing the field to a manageable number of entries for voting was no easy feat and was achieved largely be excluding entries that were improperly sized. There were too many good entries to reasonably fit all of them into a single poll, so we’re going to vote for the grand prize winner of the signed book in two rounds. Here’s the first round:
More details on the contest after the jump.
To celebrate Anole Annals‘ move to a new platform (https://www.anoleannals.org/), yesterday we announced a photography competition–winning photographs will be put into the rotation of header images displayed at the banner at the top of the page. And now we add a sweetener to the pot. The Grand Prize winner will receive a copy of Lizards in an Evolutionary Tree: Ecology and Adaptive Radiation personally signed, with great embellishment and profuse gratitude, by the author himself. Surely a valued keepsake for years to come!
In order to be considered, an image must be precisely 1000 pixels wide by 288 pixels high. We’ll credit you as photographer wherever possible, but ask that images not include any text or watermarks. You can submit your images using our blog’s new ability to easily add images to a comment; just click the “Choose File” link beneath the comment box and navigate to your JPEG photo. One way to do this is to use Photoshop to resize individual images. From the Image Menu: go to “Image Size” then change the width to 1000 px.
Get your photos in now. Deadline some time soon, once we have enough good entries. Good luck! May the best photographer win!