Even Neil Losin’s cellphone photos turn out spectacular!
Year: 2011 Page 14 of 42
Eric Pianka in the field with Varanus gouldii. Photo: Gisela Kaufmann
Eric Pianka is no stranger to bizarre conversations. As a public figure in evolutionary biology, he has engaged in numerous perplexing discussions with vociferous dissenters from the Creationist and Intelligent Design camps. On September 26, 2011 Eric Pianka received what was possibly the strangest phone call yet from David Hillis, a friend and fellow Professor at the University of Texas, Austin. Hillis informed him that rumor had it that Eric had died. Pianka learned that his obituary had been emailed to the herpetological community through the Center for North American Herpetology (CNAH), in memory of his recent passing. This is certainly not the first instance of bilocation for Eric, whose self-written obituary has been around for over two decades and available on his laboratory webpage for nearly as long. Most readers know that it is a spoof. The heading says so and the obituary ends with “Eric Pianka can be reached at eric.pianka@heaven/hell.com,” but every now and then he gets an uncomfortable email. However, this was the first time that a year of death was added to the obituary and emailed en masse to the thousands of subscribers.
Dewlap variation in Anolis distichus in Hispaniola. The photos at the bottom show the change in dewlap color along the two transects in the recent study by Ng and Glor.
Despite all of the research on anole evolution conducted in the last 40 years, one important question still eludes us: how does speciation in anoles occur? This, of course, is of fundamental importance, because the great species richness of these lizards implies that speciation has run rampant in this group. So, we’d like to know why.
We don’t know much about speciation in anoles, but we do know a little. First, it is thought that the dewlap plays an important role. Sympatric anole species almost never have identical dewlaps, and experimental and observational evidence suggests that anoles use their dewlaps for species-recognition. Hence, understanding anole speciation may, to a significant extent, reduce to understanding the factors that cause populations to evolve differences in their dewlaps.
A different perspective on anole speciation relates to the classic question of whether allopatry is necessary or whether, as suggested by many recent studies, natural selection driving differentiation—whether in allopatry or not—is a more important stimulus to genetic differentiation. Recent work in the Lesser Antilles by Thorpe and colleagues has argued that environmental differences are the primary drivers of genetic differentiation within anoles, a result also suggested by Leal and Fleishman’s studies on A. cristatellus in Puerto Rico.
In this light, perhaps the most enigmatic anole is Anolis distichus of Hispaniola.
Not content with kicking butt in Florida, Anolis sagrei has recently been reported from the Caribbean coast of Costa Rica. Photo by Melissa Losos.
Anole Annals has previously reported on the ongoing interactions between A. cristatellus and A. sagrei in Miami (for example, here and cool video here), as well as the invasion of Costa Rica by A. cristatellus. Now the plot has thickened.
In a 2009 paper in Zootaxa, Savage and Bolaños reported that A. sagrei had been collected in the vicinity of Limon, the same region in which A. cristatellus also has been introduced. Jay Savage has kindly provided further information that A. sagrei is not only common in some parts of central Limon, where A. cristatellus is also known to be common, but it is also reported to be common at a Shell gas station in the nearby town of Moin, a town in which, again, A. cristatellus is common. It will be interesting to see how rapidly A. sagrei spreads in Costa Rica, and how the two species interact. One interesting twist: in Miami, it is A. cristatellus that has invaded in the presence of an already well-established A. sagrei; in Costa Rica, the table is turned. There’s a great research project waiting to be done here!
Thanks to Duncan Irschick’s insistence that I start a project immediately upon my arrival in the PhD program at UMass, Amherst (and inspiration from a passage in Lizards in an Evolutionary Tree stating that the effects of perch instability on anole locomotion had not yet been examined – thanks, Jonathan!), I spent part of the summer of 2011 studying the effects of perch compliance (flexibility) on green anole ecology and jumping performance in the wild. This followed my examination of the effects of this perch characteristic in the lab over the last two semesters (manuscript under review).
However, finding an ideal field site for this study proved a bit more challenging than I had anticipated. Yoel Stuart invited me to work with him on a project examining the effects of interspecific competition on diet in Anolis carolinensis and A. sagrei using stable isotope analysis last summer (we continued this project through 2011), and I based my vision of an ideal field site on my experiences watching green anoles hop and run around on slender (and quite flexible) mangrove branches. I envisioned a site with plenty of small to medium diameter branches and larger trunks for the anoles to frolic on, which would provide me with plenty of data on how these lizards use compliant perches in the wild.
After a FULL week of searching (with plenty of field site advice from Yoel), I settled on a site with the type of habitat structure I had originally been seeking, as well as many small cabbage palms (< 3m) along the forest edges.
From this site: http://www.drsfostersmith.com/pic/article.cfm?aid=2791 (note: you have to go to the site for the answers; the link below is part of the image pasted into this post and is not active)
Anoles cozy up in captivity. Photo by Huai-Ti Lin
This summer I have been breeding several populations of cybotoids to assess egg stage at laying in this environmentally-varied clade of anoles. The cybotoids are trunk-ground anoles from Hispaniola, which includes Anolis cybotes and related species. Captive animals often exhibit behaviors they normally may not perform in the wild, and my colony is no exception. I offer two examples and am wondering if the readers of this blog have come across similar phenomena. First, a female Anolis cybotes ate one of her eggs. When I came to search for eggs it was already in her mouth and, when I returned later, she had swallowed it. Second, the two anoles pictured here found a cozy sleeping spot together on their bamboo pole perch. Is it odd for females to eat their own eggs, or do anoles in captivity commonly do so? I should add that these lizards are properly fed, and so hunger is not likely to be the cause of the behavior. Do mating pairs warm up to each other when kept together in captivity, or do they generally keep a healthy distance even in a cage?
Any reason to think these anoles, which arrived on Canouan in a container, presumably from Florida, are anything other than Anolis carolinensis?
Anolis nebulosus displaying. From Jenssen (1970)
In a recent post, Rich Glor–he of little faith–claimed that the multi-splendored Sitana ponticeriana outdoes all of Anolis kind by unfurling its spectacular dewlap while standing on its hindlegs. However, Joe Macedonia set the record straight in a comment, pointing out that just such behavior was reported for A. nebulosus by Jenssen. Anyone else seen anything like this?
In a recent post Miguel Landestoy shared a phenomenal photo of an unfortunate Anolis whitemani that met an untimely end in the dunes of Salinas, in the Dominican Republic. This got me thinking about odd anole deaths that I have seen in the field. Sometimes the cause of death is quite clear. Perhaps a limb has been torn off, or the body otherwise bears the marks of predation. On other occasions, however, how the anole met its fate appears more elusive.