How The Bearded Anole Got Its Name

Anolis pogus. Photo from Wildlife of St. Martin.

The resemblance is uncanny

The diminutive A. pogus of St. Martin is sometimes referred to as the bearded anole. Since anoles lack hair, facial or otherwise, one might wonder where the name comes from. In fact, Mark Yokoyama explains on his Wildlife of St. Martin site, the name is a misnomer, a misguided translation of the specific epithet pogus. Rather than being derived from the Greek pogos, the name is a reference to the cartoon character Pogo the possum! Who else would be behind this than AA faithful Skip Lazell? Anyone have any other favorite anole scientific names?

Anoles And Other Biodiversity Of Haiti: A Calendar

Calendar_June
Haiti has some spectacular anoles found nowhere else. For example, if you go to CaribHerp and click on “Haiti” in left toolbar, you see the 176 species of herps in the country. Then click filter by “Dactyloidae” and you see the 32 recognized anole species.

13 of those are endemic to the country, but there are quite a few in the works (not yet described). One beautiful endemic Haitian species, Anolis monticola, is on the cover of Jonathan’s book “Lizards in an evolutionary tree.” Deforestation continues, with only 1% forest cover remaining, so almost everything will be disappearing soon.

For several years I’ve been doing some intense field work in Haiti, and professional photographers have joined on the trips. In collaboration with the Audubon Society of Haiti (Philippe Bayard, president), we put together a large biodiversity calendar for this year, with text translated in 3 languages. It opens into a 24″ x 12″ poster. Anoles are on the cover and a month is mostly devoted to anoles. After some unexpected delay they have arrived and we’re happy to give them away, for cost of shipping/packing. If interested, see Caribnature for images of the calendar, and instructions to order:

Adventures With Phenacosaurus

Anolis heterodermus. Photo by J. Losos.

Anolis heterodermus. Photo by J. Losos.

Although many generic names have been proposed for species within the anole clade, traditionally only three other than Anolis were widely used: Chamaeleolis, Chamaelinorops and Phenacosaurus. Each of these clades—which at one time were thought to represent early, pre-Anolis derivations from the anoline line—are morphologically distinctive. The former two, Chamaeleolis and Chamaelinorops, need no introduction—they are oddball species that at first pass might not even be recognized as anoles, and that have received a modicum of scientific study. The third clade, Phenacosaurus, by contrast, has been mostly ignored. This is surprising, because at least some species are quite notable morphologically, with head casques, heterogeneous scalation, wild colors, and an all-over prehistoric appearance. Moreover, they live at remarkably high altitudes, at least by anole standards, and have a passing resemblance—some species more than others—to Caribbean twig anoles. Nonetheless, there is almost no literature on the natural history or evolution of these anoles.

Ken Miyata’s 1983 Journal of Herpetology paper is the one exception. In it, he describes the habitat use of A. heterodermus in areas near Bogotá, Colombia. His description paints the species as one that uses narrow perches on bushes and other vegetation, and that is especially plentiful in blackberry bushes. Combined with its short legs, heterogeneous body and head scalation and elongate and compressed body, reminiscent of twig anoles like A. valencienni, one might entertain the possibility that it is in functional terms a mainland twig anole.

A year and a half ago, we reported in AA on our studies of another phenacosaur, the much smaller A. orcesi from Ecuador. Our studies conclusively demonstrated that it is in all respects like a twig anole—behaviorally, it moves extremely slow; ecologically, it is found almost entirely on narrow surfaces; and morphologically, it is a Caribbean twig anole doppelgänger. But in one respect, A. orcesi was a disappointment—it looks just like any old anole, without the wildly prehistoric aspect for which the larger phenacosaurs are renowned. For this reason, it was time to examine another phenac, and what better choice could there be than A. heterodermus, the subject of Miyata’s study, supposedly common near Bogotá, and appropriately wild in appearance?

And so Rosario Castañeda, Anthony Herrel and I converged on Bogotá in late February for just this purpose, joined by Rafael Moreno, a graduate student at Universidad Nacional de Colombia, who has just completed his masters degree research on this species, with one fine paper out and more in the works. Our plan was simple: go to appropriate spots on the outskirts of Bogotá, locate lizards in the vegetation, watch them and record habitat use and behavior, then capture them and bring them back to the field lab to measure sprinting and biting capabilities and to examine their stomach contents.

Dewlap Research On Grand Cayman

Tess Driessens, but that’s no lizard

Channel 27 in Grand Cayman has just aired a report on the doctoral work of Tess Driessens (co-winner of the 2012 Anole Photo contest!) and Simon Baeckens (actually, from their webpages, this seems like Tess’s project). They’re studying the diversity of dewlap color in Anolis sagrei by looking at brown anoles throughout their range.

Female Green Anoles Exhibit Limb Length Plasticity In Natural Habitats

carolinensis by michele johnsonMuch has been written about how differences in relative limb length allow anoles to successfully occupy distinct portions of the arboreal habitat. Most research has focused on large-scale patterns of diversity, which are presumably the result of natural selection. But limb length could also be more finely tuned using an alternative process, whereby an individual’s morphology responds to environmental cues experienced throughout development. This process is known as phenotypic plasticity. We already know that anole limbs exhibit plasticity in the lab (e.g., Losos et al. 2000, 2001 – A. sagrei; Kolbe and Losos 2005 – A. carolinensis), with lizards raised on narrow perches having shorter limbs than those raised on broad perches.  But what about lizards in their natural environments; could plasticity in limb length allow lizards to become more specialized to their particular microhabitat in the wild?  This was the question that Trinity University (San Antonio) undergraduate Alisa Dill asked in summer 2010, working with fellow undergraduate Andrew Battles, regular AA contributor Thom Sanger, and me.

We studied green anole lizards in three plots in Palmetto State Park, in southeastern Texas (Figure 1).

Figure 1 from Dill et al. In press. Study plots in Palmetto State Park. The star on the small map of Texas (bottom left) indicates the location of the park.

Figure 1 from Dill et al. In press. Study plots in Palmetto State Park. The star on the small
map of Texas (bottom left) indicates the location of the park.

The three plots differed dramatically in perch availability – one was in a dense dwarf palmetto stand in a closed forest, another was trees and bushes surrounding an open field, and the third was in a light forest with many small vines and twigs. We found that female lizards in the third plot (with the narrowest perches) had significantly shorter hindlimbs than females in the other two plots, although males did not differ in limb length among the plots.  Juveniles also did not differ in limb length across the three plots, consistent with the idea that the female’s developmental experience on varying perches may influence their adult limb length.

Why this difference between the sexes?  (This difference is also consistent with results from the laboratory studies mentioned above.)  We also observed where males and females were found in their habitat and how they locomoted through it to determine if differences in behavior between the sexes could affect the way the developing lizards interact with their environment. We found that females performed fewer locomotor behaviors, spending more time on particular perches; thus, perhaps the perches had a stronger influence on female limb length than on males, who used many more perches as they move through their environment.

There is much more work to be done to further test the hypothesis of plasticity in a natural environment. After all, the previous lab experiments were performed by growing lizards on either a wooden 2×4 or a small dowel, a much simpler environment than a forest with many perch options. It would be ideal to perform a “common-garden” experiment where juvenile lizards are transplanted between environments with different perch diameters. We also don’t yet understand the developmental mechanisms that cause limb plasticity in anoles, but more information about those mechanisms will help determine why the sexes respond differently to differences in their microhabitat.

You can read more about our study in our recent publication in the Journal of Zoology, available online now in Early View.

References:

Dill, A.K., T.J. Sanger, A.C. Battles and M.A. Johnson. In press. Sexually dimorphisms in habitat-specific morphology and behavior in the green anole lizard. Journal of Zoology.

Kolbe, J.J. & Losos, J.B. (2005). Hind-limb length plasticity in Anolis carolinensis. J. Herpetol. 39, 674–678.

Losos, J.B., Creer, D.A., Glossip, D., Goellner, R., Hampton, A., Roberts, G., Haskell, N., Taylor, T. & Ettling, J. (2000). Evolutionary implications of phenotypic plasticity in the hindlimb of the lizard Anolis sagrei. Evolution 54,301–305.

Losos, J.B., Schoener, T.W., Warheit, K.I. & Creer, D. (2001). Experimental studies of adaptive differentiation in Bahamian Anolis lizards. Genetica 112-113, 399–415.

Advice Needed: GPS Tags For Giant Bronze Geckos?

Here’s a question for AA readers from Nancy Bunbury, from the Seychelles Island Foundation, who is conducting some exciting work on large gecko interactions, ecological roles, and niche separation in the palm forests of the Seychelles:

Giant-bronze-gecko-on-tree“The main species in question is Ailuronyx trachygaster (first field study on this amazing species) and one thing we would love to do is look at movements and territory size (also because we suspect it’s the main pollinator for the coco de mer which has huge conservation and inevitably commercial value). We are looking into GPS tags for the geckos (which are about 150g in weight) but it seems the technology for such a small tag requiring GPS and remote downloading is not yet available. Do you happen to know if such tags have yet been developed and who I might be able to contact for them (I’ve tried the standard larger companies for animal tracking devices)?”

Any suggestions?

Four Weeks Later, the CBS Sunday Morning Anole-Gecko Episode Now On Youtube

httpv://www.youtube.com/watch?v=_ZPpUUe1hIo

On February 17th, CBS Sunday Morning’s wonderful Nature Moment featured footage of brown anoles…but called them geckos. After we pointed this out, they took down the video from their website, but now it’s up on Youtube. You still have to watch the commercial first, though.

 

Do Bats Eat Anoles? Yes!

Fringe-lipped bat chows on a frog. Apparently, they take lizards, too. Photo from Smithsonian Science.

A quick answer to my question posed a few days ago. Some bats do, indeed, eat anoles. In particular, the fringe-lipped bat Trachops cirrhosus has been reported to do so a number of times, I now know thanks to avid anolologist and zoological polymath Anthony Herrel. Try googling “anole” and “trachops.” One hit with several references comes from the entry in Mammalian Species for Trachops, although only one paper specifically identifies anoles (A. lemurinus being the victim), as opposed to “lizards” or geckos.

Habitat Fragmentation And Population Biology Of A High Andean Lizard

Anolis heterodermus. Photo by J. Losos.

Anolis heterodermus. Photo by J. Losos.

We all know that habitat fragmentation and destruction have devastating consequences on biodiversity. Yet, one of the reasons that Caribbean anoles have been so intensively studied is that some species do extremely well in human-disturbed habitats and, because they have become so ubiquitous, they are extremely good subjects for ecological and behavioral studies.

In fact, it gives pause to realize that Caribbean islands were mostly cloaked in forest before the arrival of man, and thus many of the common anole species which are abundant in open, disturbed habitats–brown anoles, for example–were probably much less abundant in pre-historic times. In other words, it seems likely that some species are actually doing better today than in the past, but there are very few relevant data.

Anolis (Phenacosaurus) heterodermus probably occurs at higher altitudes than any other anole and has a very large altitudinal range. It’s natural history is almost unknown, and until recently, nothing had been published on its ecology and behavior since Miyata’s J. Herp. paper 30 years ago. However, that has now changed. Rafael A. Moreno-Arias has just completed his master’s degree at Universidad Nacional de Colombia on populations of this species near Bogotá, and the first paper from this work was recently published in Biotropica.

The habitat near one of the study sites in Tabio, Colombia. Photo by J. Losos.

The habitat near one of the study sites in Tabio, Colombia. Photo by J. Losos.

In that paper, Moreno looked at six habitat patches, differing in size and degree of fragmentation. By conducting a mark-recapture study,  he found that populations seemed to be increasing in all populations. Moreover, survival and growth rates were calculated to be highest in the most disturbed habitats, perhaps reflecting this species’ adaptation to edge habitats. Although too much habitat destruction is obviously detrimental–without any bushes, the species will not be able to survive–it seems that the species, perhaps like its Caribbean cousins, does just fine in fragmented landscapes. However, Moreno and Urbina-Cardona take a different, more nuanced, view on their findings, as their abstract below indicates.

Abstract:

Habitat fragmentation and loss affect population stability and demographic processes, increasing the extinction risk of species. We studied Anolis heterodermus populations inhabiting large and small Andean scrubland patches in three fragmented landscapes in the Sabana de Bogotá (Colombia) to determine the effect of habitat fragmentation and loss on population dynamics. We used the capture-mark-recapture method and multistate models to estimate vital rates for each population. We estimated growth population rate and the most important processes that affect k by elasticity analysis of vital rates. We tested the effects of habitat fragmentation and loss on vital rates of lizard populations. All six isolated populations showed a positive or an equilibrium growth rate (k = 1), and the most important demographic process affecting k was the growth to first reproduction. Populations from landscapes with less scrubland natural cover showed higher stasis of young adults. Populations in highly fragmented landscapes showed highest juvenile survival and growth population rates. Independent of the landscape’s habitat configuration and connectivity, populations from larger scrubland patches showed low adult survivorship, but high transition rates. Populations varied from a slow strategy with low growth and delayed maturation in smaller patches to a fast strategy with high growth and early maturation in large patches. This variation was congruent with the fast-slow continuum hypothesis and has serious implications for Andean lizard conservation and management strategies. We suggest that more stable lizard populations will be maintained if different management strategies are adopted according to patch area and habitat structure.

Two New Papers Criticize Proposal To Split Anolis

Last year, Nicholson et al. proposed splitting Anolis into eight genera in a paper in Zootaxa.  This idea was extensively debated in AA’s pages (e.g., 1,2,3 and links therein). Now, two papers have been published criticizing the methods and conclusions of Nicholson et al. and suggesting that the generic name Anolis be retained for the entire clade.

In a paper just published two days ago in Zootaxa, Steve Poe argues strongly against Nicholson et al.’s proposal on multiple grounds, primarily on the lack of demonstrated monophyly of most of the proposed genera. Poe concludes at the end of the introduction of the paper: “Nicholson et al. (2012) selectively adopted results of their own flawed, unstable, and conflicting analyses, selectively incorporated pertinent published data and results, and changed names for over 100 species that have never been included in a phylogenetic analysis. The proposed taxonomy is unnecessary and unwarranted according to standard taxonomic practice. It should not be adopted by the scientific or nonacademic communities.” The paper is only five pages long and is readily downloaded.

Meanwhile, within the past month, Castañeda and de Queiroz published a paper in the Bulletin of the Museum of Comparative Zoology on phylogenetic relationships within the Dactyloa clade of anoles (pdf, supplementary material). The paper is a follow-up to their 2011 paper on Dactyloa, adding morphological data to the molecular dataset analyzed previously. We’ll have more on this paper soon, but the pertinent part for today is the “Note added in Proof” appended to the beginning of the paper. The authors explain “Shortly after our paper was accepted, Nicholson and colleagues published a phylogenetic analysis of anoles and a proposal to divide Anolis into eight genera… Here, we comment briefly on their study as it pertains to the phylogeny and taxonomy of the Dactyloa clade,” and then go on to criticize Nicholson et al.’s recognition of genera (in this case, Dactyloa) and species groups that are not monophyletic in their own analyses. Moreover, like Poe, Castañeda and de Queiroz present strong critiques of the Nicholson et al. methodology and analyses, concluding “Because our results are based on larger samples of Dactyloa species (for both molecular and morphological data), as well as larger samples of molecular data (with respect to both numbers of bases and numbers of gene fragments, and including both mitochondrial and nuclear genes), and because many of their taxonomic conclusions that differ from ours are either contradicted by their own results or unsubstantiated, we do not consider any of the differences between our phylogenetic results and taxonomic conclusions compared with those in the study by Nicholson et al. (2012) to warrant changes to our proposed taxonomy. In contrast to Nicholson et al. (2012), we refrain from assigning some species to series and treat some taxonomic assignments as tentative because of contradictory results or poorly supported inferences, and we present justifications for all taxonomic decisions pertaining to species not included in our analyses.”

The Castañeda and de Queiroz critique is only two pages long. Read ’em both and decide for yourself.

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