Nat Geo just posted an article on the rediscovery of six species of Haitian frogs thought to be extinct. This seemed like a good excuse to re-tell the story of the recent rediscovery of Anolis eugenegrahami from Haiti. This remarkable “semi-aquatic” anole, known from only a single, highly degraded locality, had not been seen in quite some time until an intrepid team of herpetologists set out to look for them. Read what they found here. Now, if only someone could find A. darlingtoni….
Author: Jonathan Losos Page 131 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.
The figure above is a re-drawing from Schoener’s classic 1977 Biology of the Reptilia paper. Though “Competition and the Niche” has been widely cited, this figure, buried in the midst of the 102-page opus, has not gotten the attention it deserves. It shows that sexual size dimorphism in anoles is greatest on islands in which no other anole species are present and declines as function of the number of other anole species on an island. Anole community size is strongly correlated with island species richness, so this trend indicates that dimorphism and community richness are negatively related.
Why might this be?
During recent fieldwork with several graduate students, the topic of lizard noosing materials came up. I was accused of being an old fogey for my continued use of dental floss to make my nooses. By contrast, these young whippersnappers used some yellow stuff, pictured above. I can’t remember what it is, but it seems all the rage these days. I know that other people use various types of fishing line (I think the yellow stuff is one such type), and that everyone has their own preference. Of course, lizard noosing has doubtless been independently invented many times in various places around the world with all kinds of materials. I’ve seen local boys use blades of grass—quite effective!—in several places in the Caribbean, and once in Sri Lanka, I saw the locals using copper wire on a Calotes (not recommended). So, given all these options, what are the advantages and disadvantages of various noose materials?
Anolis aequatorialis from Ecuador
Caribbean anoles are renowned for the repeated evolution of ecomorphs, the same set of habitat specialists evolving independently on each island in the Greater Antilles. But what about in mainland Central or South America, where the majority of anole species occur? Mainland anoles have received relatively little research attention, particularly with regard to questions of ecomorphology (but see Alan Pounds’ fabulous paper from 1988), primarily because mainland species are both less abundant than Caribbean taxa as well as more cryptic, making data collection much more difficult. Mainland anoles are, as a first approximation, as diverse ecologically and morphologically as Caribbean anoles, and a preliminary study found that most mainland anoles do not fit neatly into any of the Caribbean ecomorph classes. Now, in a much broader study, Schaad and Poe compared the morphology of 255 species for seven morphological characters: snout-vent length, sexual size dimorphism, femur length, head length, lamella number, snout scale number, and the ratio of tail to snout-vent length. They found that very few species are, on morphological grounds, similar to Caribbean ecomorphs. Most of the species that do have similarity are, surprisingly enough, categorized as grass-bush anoles, although ecologically most of these species do not seem to use grass-bush habitats, from what we know of their ecology. This paper represents a good step forward in our understanding of the evolutionary diversification of mainland anoles, and how it compares to what has occurred in the Caribbean. The next step will not be so simple, however—getting habitat data for all these species.
In the mid-1980’s, Guyer and Savage proposed dividing Anolis into five genera. This proposal has mostly been rejected by the anole community, for reasons detailed in Poe (2004), Lizards in an Evolutionary Tree and the Wikipedia Norops page. The main reason is that although Guyer and Savage’s proposed genus Norops is monophyletic, all of the other proposed genera are not. Moreover, given the uncertainty that still exists about relationships at the base of the anole tree, sundering anoles into well-supported monophyletic subclades is still not possible. Finally, in Guyer and Savage’s initial paper, Anolis sensu lato was found to be monophyletic—so why bother? Even though we now know that Chamaeleolis, Chamaelinorops, and Phenacosaurus arose from within Anolis, it is much simpler to sink these genera into Anolis rather than to try to break anoles into umpteen different genera—many poorly supported.
Despite these points, and the general support for retention of an unsullied Anolis, support for Norops has one last redoubt, in Central America, and with particular strength in Costa Rica. There, the use of Norops is nearly ubiquitous, as evident in the Reptiles of Costa Rica flashcard pictured above (and for sale throughout the country).
Map from http://www.costaricamapproject.com/InfoMaps/topographic.html
I’ve completed the brief survey of the distribution of A. cristatellus in Costa Rica (see previous post for explanation). The work was hampered by rainy and cool weather. Nonetheless, several new localities were identified. In particular, we found cristatellus in Bribri, very close to the Panamanian border. We actually went to the border town of Sixaolo, and even walked across the bridge, setting foot in Panama for a full 90 seconds (border officials apparently routinely allow tourists across the border to take a photo). However, by that time, the weather was very overcast and cool, and no lizards were out. Were I a betting man, I’d wager that cristatellus is already in the land of the canal.
Anolis cristatellus in the front yard of a house in Turrialba.
I’ve just arrived in Limon, a port town on the Caribbean coast of Costa Rica, to track the spread of the introduced species A. cristatellus. Several realizations occurred to me as we wended our way down the mostly beautiful road from San Jose. First, I realized that not only have I seen cristatellus in its native range of Puerto Rico and the Virgin Islands, but I’ve also seen introduced populations in Miami and the Dominican Republic, as well as here. This species gets around!
I report from Quepos, near Manuel Antonio National Park, one of the most popular tourist destinations in Costa Rica. As you might imagine, the place is silly with vendors and shops selling all manner of trinkets and tchotkes: t-shirts, postcards, carvings, you name it. And befitting Costa Rica’s ecotourist slant, much of this merchandise has a wildlife theme. Red-eyed tree frogs, sea turtles, toucans, geckoniform lizards—I’m sick of them all. I’ve searched high and low, through every shop and stall, here and elsewhere, and there is not a single anole-themed product to be found. Imagine the money to be made: slender anole postcards, elegant painted carvings of A. biporcatus. I’m sure I’m not the only ecotourist here thirsting after a little anoline piece of Costa Rica to take home as a beloved keepsake. Herpetological entrepeneurs, get to it!
My name is John Phillips. I am an undergraduate in Kirsten Nicholson’s lab at Central Michigan. Kirsten and I were discussing some interesting behavior I observed by A. laeviventris and A. cupreus during our Nicaragua trip last summer. Multiple individuals upon capture appeared to ‘play dead’ until I stopped holding them securely, whence they suddenly sprang to life and escaped. Kirsten thought you may know of any related instances of such behavior in anoles, and she has encouraged me to write this observation up in Herp Review so I was wondering if anyone knew of related instances in other anoles. If so, could you email me at: phill1jg@cmich.edu?