SICB 2015: Trade-Offs Between Pre- and Post-Copulatory Sexual Selection

The focus on sexual selection in reptiles continued yesterday when Ariel Kahrl, a graduate student in Bob Cox’s lab at the University of Virginia, gave her presentation on investment tradeoffs between pre- and post-copulatory sexual selection. She predicted that investment in male-male competition (an important component of pre-copulatory sexual selection) constrains an organism’s ability to invest in post-copulatory selection such as sperm competition. To test this hypothesis across squamates, Ariel performed a meta-analysis using data from 143 species (111 lizards and 32 snakes), and she reported her results in the DCPB (Division of Comparative Physiology and Biochemistry) Wake Award competition for Best Student Presentation. Using male-biased sexual size dimorphism (SSD) as a proxy for pre-copulatory selection and relative testis size as a proxy for sperm competition, Ariel found that both these traits were negatively correlated across the group – that is, species with relatively larger male body size had relatively smaller testes. In other words, in species where males invest more in access to females, the less they invest in sperm! This pattern was strongest among territorial lizards (like anoles). So, it appears that there are significant trade-offs between pre- and post-copulatory selection in squamates.

Ariel is following up on this work with a large-scale comparative analysis of sperm morphology in anoles, to determine if the interaction between pre- and post-copulatory selection shapes sperm evolution. She ended her talk showing how impressively variable sperm traits are among anoles – perhaps a sneak peek for her talk next year?

Anolis sperm! Photo from Ariel Karhl's website.

Anolis sperm! Photo from Ariel Kahrl’s website.

SICB 2015: Lizards in a Warming World: Ectotherm Plasticity in Changing Thermal Environments

While it wasn’t technically a talk about anoles, we’re sure AA readers will want to know the latest work from Alex Gunderson (pictured below), currently a postdoc with Jonathon Stillman at UC Berkeley and SFSU. Yesterday at SICB, Alex described his work on thermal plasticity in five major ectotherm clades (insects, crustaceans, fish, amphibians, and reptiles). Using acclimatization response ratios (ARR) for hundreds of species from these groups, Alex tested the hypothesis that animals in more variable thermal environments would exhibit greater flexibility in thermal acclimation. While he did not find support for that relationship, he did find that habitat type has a strong association with plasticity, as freshwater and marine species have more thermal flexibility than terrestrial species (like our favorite anoles). Next, he extracted the standard deviation of weekly temperatures from the NOAA database, and found that terrestrial animals had more plastic responses to cold tolerance (critical thermal minimum or ‘CTmin’), but not heat tolerance (critical thermal maximum or ‘CTmax’). Additionally, he found and there was no relationship between standard deviation of weekly temperatures and tolerance traits in aquatic species. Thus, terrestrial species had greater plasticity to lower temperatures than higher temperatures. Overall, he found that many types of ectotherms have relatively low capacity for acclimation. This result suggests that plasticity in acclimatization responses will not allow animals to compensate for rising temperatures across the planet, and behavioral responses will instead become more critical.

Alex Gunderson, themal ecologist. Photo from his website.

Alex Gunderson, thermal ecologist. Photo from his website.

SICB 2015: Anolis proboscis Display Behavior

Anolis proboscis, showing the male-specific proboscis. Photo by D. Luke Mahler.

A longtime favorite here at Anole Annals, the Ecuadorian Horned Anole (Anolis proboscis) made an appearance at SICB. Diego Quirola and colleagues from Pontificia Universidad Católica del Ecuador described the use of the proboscis during social interactions. They captured male and female anoles and videotaped staged male-male and male-female interactions. From the videos they were able to quantify behavioral patterns of these fascinating lizards. They did some very anole-like behavior, but they definitely have a flair all their own! With such a fascinating, chameleonic appendage one would expect some important functions of the proboscis, and one would not be disappointed. Watching videos that Diego had on display revealed social behavior very reminiscent of chameleons, with males puffing up, curling their tails, and swaying while doing the more typical anole dewlap extensions.

Then there’s the proboscis. This structure, much like the dewlap, is used during both courtship and agonistic interactions. In both contexts, males actually lift the proboscis. Yes, they can move the proboscis up and down, something not seen in chameleons with rostral appendages (no, we don’t know how they do it!). Diego suggests that the proboscis is lifted to either stimulate females or allow the male to bite the nape as other lizards do while copulating. Males also display a behavior called “proboscis flourishing” where the proboscis is prominently displayed while moving the head side to side. During agonistic interactions it may serve as a dominance indicator, though they are still working on those analyses. Proboscis anoles seem to be at the low end of aggression for anoles, but males occasionally fight and lock jaws. During male fights the proboscis likely gets in the way, and it appears to be purposely lifted during these fights. It’s possible that they lift it to keep the rival male from latching onto their snout, or it could be moved so that they can get better bites in. I was very much looking forward to learning more about these anoles, and I was not disappointed. As more work is done on these fascinating anoles we’ll be able to better understand why it has evolved such an interesting, and un-anole-like appendage, as well as the unique behavior that is associated with it.

SICB 2015: Use it or Lose it: A Study of Dewlap Size Plasticity in Green Anoles

Anolis carolinensis dewlapping. Photo by Cowenby available on Wikipedia.

Anolis carolinensis dewlapping. Photo by Cowenby available on Wikipedia.

On Sunday, Simon Lailvaux of the University of New Orleans gave one of the first anole talks of the SICB meeting, on his work examining the mechanisms underlying seasonal fluctuations in dewlap size. Simon began the talk by describing observations from field and lab studies (Irschick et al. 2006) that revealed that during the summer breeding season, when male anoles extend the dewlap frequently during behavioral displays, male dewlaps are much larger than during the winter nonbreeding season when the dewlap is used rarely. Simon and his lab then conducted a dietary-restriction study to test the hypothesis that this seasonal plasticity is due to resource availability, but found that diet was not associated with dewlap size (Lailvaux et al. 2012).  So, the search for the mechanism underlying this change in dewlap size was on.

Along with several colleagues from Trinity University – Jack Leifer (a materials engineer) and anolologists Bonnie Kircher and Michele Johnson (full disclosure – that’s yours truly), Simon and colleagues then conducted a laboratory experiment to determine whether reduced dewlap size related to less use in the nonbreeding season. To conduct the experiment, the researchers prevented dewlap extension in one set of male green anoles by tying dental floss loosely around their throats, and compared the dewlap size and skin elasticity of those lizards to an unrestrained control group that could dewlap at will. They found that dewlap size in the restrained group continually decreased over time, as compared to unrestrained lizards that, again, exhibited larger dewlaps in the breeding season. Together, these results suggest that use of the dewlap is directly related to its size. Then, the researchers measured the elasticity of dewlap and non-dewlap (belly) skin, and found that the dewlap is more elastic than belly skin, and that both types of skin samples were more elastic in the summer breeding season than in the winter. Because skin is a dynamic tissue whose mechanical properties are altered by sex steroid hormones, Simon suggested that dewlap size plasticity may be the result of seasonal endocrine fluctuations, combined with behavioral use of the structure.

These results suggest so many next steps.  Look for the upcoming manuscript describing this work in more detail!

References

Irschick, D.J., Ramos, M., Buckley, C., Elstrott, J., Carlisle, E.,Lailvaux, S.P., Bloch, N., Herrel, A. and Vanhooydonck, B. 2006. Are morphology -> performance relationships invariant across different seasons? A test with the green anole lizard (Anolis carolinensis). Oikos 114: 49-59.

Lailvaux, S.P., Gilbert, R.L. and Edwards, J.R. 2012. A performance-based cost to honest signaling in male green anole lizards (Anolis carolinensis). Proceedings of the Royal Society of London B: Biological Sciences 279: 2841-2848

SICB 2015: Transcriptomic Analysis of Anole Growth Mechanisms

Photograph of a male Anolis sagrei from Christian Cox’s website.

Squamates vary widely in the magnitude and direction of body size dimorphism, which refers to the tendency for the sexes to exhibit different body sizes. Some lineages possess male-baised dimorphism while others have female-baised. The effects of testosterone on mediating sexual size dimorphism in different squamate lineages has long been the study of the Cox lab at the University of Virginia.  Christian Cox (of no relation to his advisor) has now reported some exciting steps forward in the search for the mechanisms regulating body size dimorphism in the brown anole, Anolis sagrei. Cox is in the process of carrying out a  transcriptome-wide analysis of the genes responsible for sexual dimorphism, with particular focus on examining the genes along the insulin growth factor-growth hormone axis (IGH-GH), which is the same pathway that was reported about yesterday.  In his experiment Cox implanted testosterone pellets under the skin of juvenile male and female lizards and then looked for differences in size and gene expression. Increased levels of circulating testosterone prompted increases in body size in both males and females grew to larger sizes, indicating that females have not lost the ability the respond to testosterone. But to better understand the growth axis controlling this difference Cox took a large step forward by also comparing gene expression in the liver of experimental (implant) and control (intact) animals. As the liver is a major regulator of growth via its regulation of the IGH-GH, Cox expected that this tissue would respond to testosterone treatment. This is precisely what Cox found. Specifically, he found a number of genes that are naturally regulated in different ways in males and females and additional genes that responded to the testosterone treatments. To conclude, Cox pointed out that an important next step will be to compare castrated lizards to those intact lizards with the testosterone implant to more clearly elucidate the gene network directly responding to testosterone. But perhaps the most exciting work will come with Cox and his collaborators examining the growth mechanisms of species with male-baised and female-baised patterns of dimorphism to more thoroughly understand how evolution has reshaped these gene regulatory networks during squamate evolution.

 

SICB 2015: If You Want to Invade, You Better Be Bold

Lauren and her poster

Lauren Davis presenting her work on invasion success in lizards.

As our planet becomes increasingly connected and humans facilitate novel species interactions, we must ask why some introduced species are destructive and others relatively harmless. Lauren Davis, a senior in Dr. Michele Johnson’s lab at Trinity University, conducted a study on behaviors, and their neural correlates, that may influence the invasiveness of non-native lizards. She compared the invasive Anolis sagrei to the native Anolis carolinensis, the invasive House Gecko (Hemidactylus turcicus), and the native Texas Banded Gecko (Coleonux brevis). They hypothesized that highly invasive species display more ‘bold’ behaviors (in this case, the number of enclosure boundaries crossed during an experimental period) and have larger and/or denser neurons in associated brain regions than less invasive species. While there are many documented behavioral trials with boldness in Anolis, geckos have received little attention in this regard. Lauren and her fellow researchers found that A. sagrei is indeed bolder than A. carolinensis, but that the two gecko species do not differ in traits associated with the boldness syndrome (Fig. 1).

Invasive Brown Anoles are bolder than native Green Anoles

Figure 1: Invasive Brown Anoles are bolder than native Green Anoles

The researchers also found that neuron size in brain regions known to influence boldness and aggression were opposite than expected values, so the team plans to analyze neuron density in these regions to help explain the observed behaviors. This is one of the first studies comparing behavior and brain morphology to invasion success, and it paves an exciting path towards our understanding of species interactions in our changing world.

Lauren is graduating in May, and hopes to work in conservation or public health before continuing her education in graduate school.

SICB 2015: How Do Anoles Get Big?

photo from;http://www.saumfinger.de/anolis_equestris.html photo by:Uwe Bartlet ?

One of the largest anoles, Anolis equestris (photo by Uwe Bartlett)

From the diminutive twig anole to the monstrous crown-griant anoles, Anolis lizards vary dramatically in their body size. Much research has focused on the patterns of body size variation among Caribbean species, how changes in body size are correlated with habitat differences among species, and rates of body size evolution upon invasion to new islands, yet an important question remains to be addressed in this body of literature, “how do anoles change body size?” S. Griffis and Dr. D. Jennings of Southern Illinois University at Edwardville are attempting to address this among Cuban anoles by searching for DNA sequence differences in known growth factories. But they are using what might be considered an unlikely model for lizard body size variation: dogs. Several years ago, Elaine Ostrander’s lab at the NIH uncovered that coding differences in the growth factors IGF were responsible for the body size variation in dogs. To a mechanist like myself, it was a surprise that this variation could be traced to coding differences in the genes, not to the levels of circulating growth factors. The authors of this poster are following Ostrander’s lead by looking for coding differences in genes involved with the IGF growth axis. But to keep their options open they are also collecting data on circulating hormone levels. When complete, if there are differences in the IGF growth axis contributing to differences in body size, Griffis and Jennings will find it.

SICB 2015: A Synthesis of Sexual Selection and Life History Perspectives

Anolis sagrei mating. Taken from the Cox lab website.

Anolis sagrei mating. Taken from the Cox lab website.

On the first day of SICB 2015 Robert Cox gave an interesting talk about reproductive investment and sexual selection in lizards. At the center of his talk was the striking notion that males and females are different biologically, yet should still be integrated into cohesive theories of sexual selection. According to Dr. Cox, past theory has generated mutually exclusive ideas about the costs of reproduction for each sex. Whereas theories about females have focused on life history and investment in the egg and offspring, theories about males have focused on mating investment. Cox stressed that this is overly simplified and doesn’t reflect biological reality,  as males and females also share many of the same costs of reproduction as well. Issues like growth, survivorship, energy storage, and parasite load are shared between the sexes. Dr. Cox is now trying to test how sex-specific reproductive mechanisms affect these shared reproductive constraints by surgically removing the gonads of each sex. Preliminary analyses show that parasite load appears to be a shared effect among the sexes regardless of the underlying mechanism (testosterone derived from testes versus estrogen derived from the ovaries). Studies directly comparing the underlying mechanisms of sexual dimorphic anatomy, physiology, and behavior are critical for the further development of sexual selection theory and for improving our understanding of anoles. Studies like Dr. Cox’s are an important step in that direction.

 

SICB 2015: Anoles in the Big City! Urban Environments and Predator Escape Behaviors

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Anolis cristatellus in Miami, Florida. Picture by Jason Kolbe.

Humans and wildlife are sharing the same spaces more and more frequently, but there’s still much that we do not know about how animal behavior is altered in urban environments. To address these questions, graduate student Kevin Avilés-Rodriguez (pictured below) and Dr. Jason Kolbe of the University of Rhode Island studied the responses of Anolis cristatellus to simulated predators in urban and natural environments in Puerto Rico. They found that lizards in an urban habitat had shorter flight initiation distances (the distance a simulated predator – in this case, Kevin – could approach before the lizard fled) than in a natural, forested site.  In addition, lizards’ predator-escape behaviors generally corresponded to the sizes of their perches and to their proximity to vegetation, but perch types differed between the urban and natural sites.  Whereas lizards in natural habitats tended to jump into nearby plants to escape, urban lizards tended to avoid capture by squirreling on larger, more isolated perches.  Kevin also reported that lizards perching on cement walls had adjusted their predator responses dramatically, as they generally did not jump or squirrel. In sum, this study suggests that habituation to humans and/or human-shaped habitats have altered the responses of these lizards to potential predators in important ways.

Kevin Aviles, stalking lizards in the field. Photo from Kolbe lab website.

Kevin Aviles, stalking lizards in the field. Photo from Kolbe lab website.

Male A. sagrei with dewlap extended and dorsal crest raised. Image from wikipedia.org.

SICB 2015: What Causes Dorsal Crest Erections in Anoles?

We’ve all seen anole lizards extend their dewlaps, but the social displays of the many species of anoles also include the erection of a dorsal crest. But, what underlies the formation of these crests? Although many of us have talked about this, undergraduate John Ficklin, along with Morgan Gerace and Dr. Matthew Rand, all of Carleton College, aimed to find out and presented their work today at SICB. By injecting Anolis sagrei and A. carolinensis lizards with isoproterenol (a β-adrenergic agonist), they caused crest erection in males, but not in females. They then used histological techniques to examine the cellular morphology of the crest. What they discovered is that male anoles have a clearly-defined organ they dubbed the “crest capsule” (a structure female anoles lack), and when this capsule is filled with an edema from local blood vessels, the crest extends vertically. Collagen fibers appear to help maintain the crest’s vertical orientation during its display.  After inflation, the edema then drains into the subcutaneous space surrounding the capsule, causing the crest to deflate. They found no evidence of the involvement of muscles, cartilage, or vascular sinus in crest erection.

In sum, John Ficklin and his colleagues have solved one of the big questions of anole display!

SICB 2015: How Do Lizards Move in Nature?

Jerry HusakHow do lizards move in nature? Note the added emphasis on “in nature.” For many years people have studied the mechanics and patterns of of lizard movement and anoles have played an important role in this research. But today Jerry Husak of the University of St. Thomas in St. Paul reminded us that most of this research has focused on characterizing maximum performance ability, despite the fact that  animals rarely achieve this level of activity in nature. For example, most of the time many lizards are merely scurrying about on the ground and not sprinting at their full ability. Hence, although measuring maximal spring speed in the lab is a common theme, this measurement may not actually reflect what animals do in nature. Dr. Husak also stressed to the audience that animal locomotion is context dependent. Specifically, a lizard’s speed depends on whether it is moving in grass or over rocks, and whether it is foraging or fleeing from a predator. During his enlightening discussion, which included a description of him trying to sprint on a frozen Minnesota sidewalk, Dr. Husak described a series of biotic and abiotic factors that should be incorporated into models of terrestrial lizard movement.  Finally, he concluded by challenging our obsession with maximum sprint speed once again by asking whether running at top speed can lead animals to make to costly mistakes. Based on a set of foraging data, he showed that this may be the case.  Dr. Husak’s talk highlighted the importance of understanding the natural habits of lizard behavior and performance. 

SICB 2015: Convergence in Body Shape among Squamates

P. Bergmann

Patterns of Convergence in the Body Shape of Squamate Reptiles

SICB 2015 is off and running and what better way to kick it of than with a lizard talk? Phillip Bergmann of Clark University filled the 8:15 time slot on day one with an intriguing evaluation of broad-scale body shape convergence among squamates. This is a perennial topic on Anole Annals due to the well-studied patterns of convergence among Anolis lizards and, indeed, Dr. Bergmann highlighted anoles early in his talk. He asked whether common functional (ecological) situations lead to body shape convergence at large scales. Rather than search for global patterns of convergence, Dr. Bermann used hypotheses specific to the transformations that occur when lineages transitioned into new habitats. As he pointed out, it is not surprising to find convergence in body shape occurring throughout squamate – after all, convergence is ubiquitous across the tree of life. He concluded his talk highlighting what he feels are some of the most pressing “Big Questions” regarding convergence which included the methods we use to detect convergence, the role of constraints in shaping convergence, and elucidating the mechanisms underlying convergence. Ultimately it was a thought-provoking talk both from the perspective of squamate organismal diversity and the topic of convergence more broadly.

Let SICB 2015 Commence!

When I was a kid, the first week of January used to be such a bummer for me because it meant that the holidays were over. But now the first week of each year means that the annual meeting of the Society for Integrative and Comparative Biology (SICB) is underway! The meetings run from January 3rd until January 7th, and there are 30 talks/posters this year about anoles! I won’t be attending this year, as I’m currently based out of Australia (AKA land of no anoles), so I’ll be looking forward to the posts on this blog to hear what’s new and exciting in Anolis research. Stay tuned!

Two More New Anole Species

Introducing Anolis alocomyos.

Introducing Anolis alocomyos.

Gunther Köhler and colleagues have done it again!This time, they’ve taken Anolis tropidolepis  in Costa Rica and divided it into three species in the December 2014 issue of Mesoamerican Herpetology.

The back-story: the A. pachypus complex (as the authors refer to it, except using the generic name Norops) has in recent years been split in Panama into four species, but complex member A. tropidolepis remained intact in Costa Rica. These lizards are long-limbed, narrow-padded lizards found near the ground at high elevations.

Based on eight years of collecting, Köhler and colleagues now split the group in Costa Rica into three species that are somewhat genetically differentiated at the 16s mitochondrial gene and that differ in hemipenial morphology and to some extent in scalation.  One of the OTUs (operational taxonomic units), comprised of a single individual, has the mtDNA of one species and the hemipenis morphology of another and is interpreted as evidence of hybridization.

The paper includes interesting discussion of bar-coding and how one goes from degree of genetic differentiation to decisions on species delineation.

One highlight of the paper was the icon shown below, which occurred at the bottom of one of the pages at the end of the article without explanation. A quick look at the other two papers in the issue revealed that each has its own logo–nice!

icon

Eyelash Vipers Down Anoles

Photo by Christopher E. Smith

Photo by Christopher E. Smith

Christopher E. Smith recently tweeted this photo of an eyelash viper consuming an anole. The photo was taken in Tortuguero, Costa Rica in 2008 and the incident is recorded on HerpMapper. He provided additional photos which show the anole more fully. It appears to me to be an A. limifrons, though the regenerated tail means that the usual tail banding is not present.

limifrons eaten by eyelash christopher smith II

 

And two more, for good measure:

limifrons eaten by eyelash christopher smith III

And Down the Hatch!

Photo by Christopher E. Smith

Photo by Christopher E. Smith

In going back through the AA archives, I’ve discovered that we previously posted a link to these photos in April, 2011! But here they are again for your renewed viewing pleasure.

Consumption of A. limifrons by eyelash vipers has been previously reported, including a lovely photo by Harry Greene in Lizards in an Evoutionary Tree. A quick Google Image search yields a number of photos, although I suspect most are in captivity.

Here’s an interesting one:

This, in turn, led me to The Many Creatures of Costa Rica blog, which has a whole series of photos of this predation event from La Selva in Costa Rica. The anole seems to be A. humilis. Here’s another from the series:

 

Movement Rates and Microhabitat in Anolis carolinensis

In an earlier post on anole foraging mode, Jonathan Losos remarked that “much remains to be learned about the specifics of anole foraging and how it differs among species.” One thing we do know, however, about fine-scale variation in foraging mode is that it can depend on microhabitat. Both interspecific and intraspecific variation in movement rates in anoles suggest that low-perching anoles in trunk-ground habitats move less frequently than high-perching anoles in arboreal trunk-crown habitats (Lister and Aguayo 1992; Cooper 2005; Johnson et al. 2008)

One reason that anoles may shift from low to high perches is the presence of a congener. In the spoil islands of Mosquito Lagoon, FL, Anolis carolinensis occurs either on its own or in sympatry with A. sagrei, and recent research by Stuart, Campbell and colleagues showed that the green anoles perch higher on two-species islands than on one-species islands. Back in 2010 as a field assistant on this project, I collected some data on the foraging mode of green anoles on five of these islands, to test the prediction that allopatric A. carolinensis that inhabit lower perches in trunk-ground microhabitats have lower movement rates than sympatric A. carolinensis that occupy higher perches in trunk-crown microhabitats. I used the standard measure of movement per minute (MPM) to quantify foraging mode from a total of 204 lizards (78 females and 126 males, 110 lizards from one-species islands and 94 from two-species islands).

Movement data are messy and MPM varies a lot across individuals, with coefficients of variation within islands ranging from 41% to 74%. Moreover, when one watches lizards go about their lives, one readily realizes that they move for many reasons other than to feed and that MPM is therefore better interpreted as an index of activity than as a measure of foraging per se (Perry 2007).

I found that females show the predicted increase in MPM with increased perch height when sympatric with A. sagrei, while males show the opposite pattern, with higher MPM in the absence of A. sagrei (there was something of an interaction between A. sagrei presence and sex in the ANOVA on island means of MPM for males and females; F1,1=4.02, p=0.09).

 

Means of island means of MPM for male and female green anoles in one-species and two-species islands in Mosquito Lagoon, FL.

Means of island means of MPM for male and female green anoles in one-species and two-species islands in Mosquito Lagoon, FL.

That males and females differ behaviorally in their response to A. sagrei is perhaps not surprising, as males and females have different motives for movement during the breeding season. Male anoles spend a majority of their time in the breeding season engaged in social interactions and forage only opportunistically. Females, on the other hand, spend most of their time foraging in both the breeding and the non-breeding seasons (Lister and Aguayo 1992; Jenssen et al. 1995; Nunez et al. 1997). The increase in MPM in sympatric females relative to allopatric females therefore suggests that lizards forage more actively at higher perches. In contrast, the decreased movement rates of males on two-species islands might result from male territories being smaller on two-species islands than on one-species islands, with fewer movements required to defend these territories.

Aside from these speculations, the results shown here only allow one to conclude that movement behaviour is complex. Discerning why an individual is moving at any given time, coupled with much larger sample sizes than obtained here, including repeated measurements of the same individuals moving in different contexts, will be crucial to furthering our understanding of fine-scale variation in movement rates and its relationship with microhabitat

IMG_3060

Citations

Cooper WE (2005) Ecomorphological variation in foraging behaviour by Puerto Rican Anolis lizards. Journal of Zoology 265: 133-139

Jenssen TA, Greenberg N, Hovde KA (1995) Behavioral profile of free-ranging male lizards, Anolis carolinensis, across breeding and post-breeding seasons. Herpetological Monographs 9: 41 – 62

Johnson MA, Leal M, Schettino LR, Lara AC, Revell LJ, Losos JB (2008) A phylogenetic perspective on foraging mode evolution and habitat use in West Indian Anolis lizards. Animal Behavior 75: 555-563

Lister BC, Aguayo AG (1992) Seasonality, predation, and the behaviour of a tropical mainland anole. Journal of Animal Ecology 61: 717-733

Nunez SC, Jenssen TA, Ersland K (1997) Female activity profile of a polygynous lizard (Anolis carolinensis): evidence of intersexual asymmetry. Behaviour 134: 205-223

Perry G (2007) Movement patterns in lizards: measurement, modality, and behavioral correlates. In: Reilly SM, McBrayer LB, and Miles DB (eds.) Lizard Ecology. Cambridge University Press, Cambridge pp 13-48

Anolis triumphalis: A New Species of pentaprion Group Anoles from Panama

triumphalis1

The march of Anolis to 400 species continues with a paper by Kirsten Nicholson and Gunter Köhler describing a new species from Panama.Actually, according to the Reptile Database, there are already exactly 400 species! So this makes 401.

Previously, ten members of the pentaprion group were known, seven from Central America, three from South America.

triumph2The new species, A. triumphalis (described under the name Norops triumphalis) has a large orange dewlap, thus distinguishing it from all other members of the group, which have a reddish-purple dewlap.*

Anolis triumphalis is described from a single male that was captured crossing the road between pastures with tall grass and a fence composed of wooden fenceposts and living trees. As the authors note, pentaprion group anoles are very similar to West Indian twig anoles. This story is reminiscent of the rediscovery of another mainland twig anole, A. proboscis, found after forty years by a group of birdwatchers when a male was observed crossing a road in front of a mini-van. Why the twig anole crossed the road is clearly a question that will puzzle philosophers for years to come.

*The authors state that the large, orange dewlap doesn’t distinguish A. triumphalis from A. sulcifrons, but as far as I’m aware, the latter species has a red-purple dewlap like other pentaprion group members.

Here’s the abstract:

We describe the new species Norops triumphalis sp. nov. from Darién, Panama. Norops triumphalis differs from all congeners by having a combination of (1) smooth, bulging, subimbricate ventral scales; (2) a short tail, ratio tail length/SVL 1.54; (3) short hind legs, longest toe of adpressed hind leg reaching to ear opening, ratio shank length/SVL 0.24; (4) a lichenous body pattern; and (5) a very large yellowish orange dewlap in males. In external morphology, N. triumphalis is most similar to the species of the N. pentaprion group. Norops triumphalis differs from the other species in the N. pentaprion group, except N. sulcifrons, by having a very large orange male dewlap (vs. a large red or pink dewlap) and an unpigmented throat lining. Norops triumphalis differs from N. sulcifrons by having the supracaudal scales not forming a serrated crest (vs. a distinct serrated caudal crest present in N. sulcifrons), 4 supracaudal scales per segment (vs. 3 supra-caudal scales per segment in N. sulcifrons), greatly enlarged outer postmental scales, about four times the size of adjacent medial scales (vs. moderately enlarged outer postmental scales, about twice the size of adjacent medial scales, in N. sulcifrons), and no enlarged postcloacal scales in males (vs. a pair of moderately enlarged postcloacal scales present in male N. sulcifrons). We further provide a standardized description and illustrations of the holotype of N. sulcifrons.