Wendy Lee photographed a Graham’s anole eating another anole, probably an A. lineatopus. The event went down on November 25, 2013 in Runaway Bay, Jamaica, where Wendy runs a wildlife rescue facility, the Seven Oaks Sanctuary for Wildlife. We’ve discussed anoles eating other anoles several times in these pages, most recently with regard to A. sabanus.
Greetings AA readers! It’s that time of year again – leaves are changing, the air is getting brisk, and it’s time for the Anole Photo Contest!
As in previous contests, the Anole Annals team is calling for submissions of your best anole photographs for our 2017 calendar.
The editors of Anole Annals will choose a set of 30-40 finalists. Twelve winning photos will then be selected by readers of Anole Annals and a panel of anole photography experts. The grand prize winning and runner-up will have his/her photo featured on the front cover of the 2016 Anole Annals calendar, second place winner will have his/her photo featured on the back cover, and they’ll both win a free calendar! (Last year we had so many submissions we had to make two calendars; check them out here and here).
The rules: submit your photos (as many as you’d like) as email attachments to anoleannalsphotos@gmail.com (note the change in email address from last year). To make sure that your submissions arrive, please send an accompanying email without any attachments to confirm that we’ve received them. Photos must be at least 150 dpi and print to a size of 11 x 17 inches. If you are unsure how to resize your images, the simplest thing to do is to submit the raw image files produced by your digital camera (or if you must, a high quality scan of a printed image). If you elect to alter your own images, don’t forget that it’s always better to resize than to resample. Images with watermarks or other digital alterations that extend beyond color correction, sharpening and other basic editing will not be accepted. We are not going to deal with formal copyright law and ask only your permission to use your image for the calendar and related content on Anole Annals (more specifically, by submitting your photos, you are agreeing to allow us to use them in the calendar). We, in turn, agree that your images will never be used without attribution and that we will not profit financially from their use (nobody is going to make any money from the sale of these calendars because they’ll be available directly from the vendor).
Please provide a short description of the photo that includes: (1) the species name, (2) the location where the photo was taken, and (3) any other relevant information. Be sure to include your full name in your email as well. Deadline for submission is November 4, 2016.
Good luck, and we look forward to seeing your submissions!
Last week, Miguel Landestoy provided the details on the discovery of Anolis landestoyi, the new species from the Dominican Republic. The paper was published recently in The American Naturalist. Here’s what the press had to say:
The Canadian Broadcast Corporation:
A Caribbean lizard that remained undiscovered for many years despite its large size and distinctive looks has been identified as a new species.
The lizard, an anole that looks like a chameleon and has a similar talent for camouflage, lives in the canopy of a rare type of forest in the western Dominican Republic. Adults have a body length of up to 13.5 centimetres and a tail up to 18 centimetres long, making them unusually large for an anole. The new species is described as a “giant chameleon-like lizard” in a study published in the journal The American Naturalist.
The lizard was first spotted in 2007 by Dominican naturalist Miguel Landestoy while he was studying endangered birds called bay-breasted cuckoos.
‘There’s nothing else like that in and around the island.’– Luke Mahler, University of Toronto
“He noticed that these birds were agitated and seemed to be attacking something,” recalled Luke Mahler, a University of Toronto biologist and the lead author of the new study.
When Landestoy got closer, he saw a lizard and snapped a picture of it.
Convinced it was a new species, he showed the photo to Mahler, a lizard researcher who was working in the Dominican Republic at the time. But the photo was so grainy that Mahler couldn’t tell much other than it was an anole. He suggested that Landestoy try to capture a specimen.
Several years later, Landestoy spotted the lizard again and took some better photos.
Luke Mahler (left) and Miguel Landestoy (right) pose for a photo shortly after capturing the first specimens of Anolis landestoyi. (Luke Mahler)
“As soon as he sent the pictures,” Mahler recalled, “I was like, ‘What the expletive is that? … There’s nothing else like that in and around the island.”
He added that the Caribbean has been very well explored, so that typically, any new species found there are so similar to existing species that they can only be distinguished with DNA testing.
The new lizard was a big anole, with stubby limbs, a short tail, and green-grey and light brown scales that help it blend in among the moss-covered branches of the semi-dry tropical forest where it lives.
“It’s super camouflaged, basically. It looks just like the bark,” said Mahler, who thinks that’s why it’s never been spotted before. “It’ll sit there and hug a branch and very slowly move one limb at a time.”
The lizard is similar to related anoles found in Cuba called chamaeleolisor chamaeleonides because they’re also chameleon-like.
That’s intriguing because biologists have always expected to find a lizard similar to chamaeleonides on Hispaniola, the island shared by Haiti and the Dominican Republic. Islands in the Caribbean tend to have similar environments and tend to evolve species with similar adaptations, even if they are not closely related.
The newly discovered Hispaniolan lizard Anolis landestoyi (top) is very similar to the Cuban species A. porcus (bottom), part of a group called chamaeleonides. (Miguel Landestoy)
Mahler says more analysis needs to be done to figure out if the new lizard is similar to the chamaeleonides lizards because it’s closely related or because it evolved similar adaptations over time.
The new lizard has been named Anolis landestoyi after its discoverer.
Sadly, even though the new species was so recently discovered, it may not be around for much longer.
“We think that they’re probably quite endangered,” Mahler said.
That’s because it lives in a unique type of forest halfway up a mountain slope close to the border with Haiti. Although the forest is in a reserve called Lomo Charco Azul that’s officially protected, it’s threatened by illegal logging for agriculture, livestock grazing, and firewood.
The researchers are requesting that the new lizard be officially listed as critically endangered. They hope the new discovery will help draw attention to the threats to its habitat and lead to better protection.
We tend to think the contours of biodiversity are well known, especially in extensively studied areas. However, this is not necessarily the case and sometimes strikingly new species are discovered even in well-trod areas. A case in point is the country of the Dominican Republic, which has been thoroughly studied by biologists for more than 40 years, particularly by herpetologists who have exhaustively catalogued the reptiles and amphibians there for several decades.
In a (somewhat) recent blog post entitled “Is there a crisis in Anolis taxonomy?”, Julian Velasco invited discussion on a perceived decline in the number of new anole taxonomists. While it was a fun look at the dynamics of anole taxonomy over time, I couldn’t help but feel like there is a more pressing taxonomic crisis going on right now, and it affects many of the researchers that frequent this blog.
I fear too many species of Anolis are being described based on questionable evidence. While this problem is not unique to anoles (a common term for it is “taxonomic inflation”; Isaac et al. 2004), a number of recently described anole species may be the result of overzealous taxonomic splitting. I will give some examples below and then briefly discuss two lines of evidence that I believe are often used to divide species inappropriately. Before I do so, it’s worth stating up front that I’ll focus on the work of Dr. Gunther Köhler and colleagues. This shouldn’t be surprising, as Dr. Köhler is the most prolific living describer of anole species. The following criticisms should not be seen as personal, as Köhler is not unique on any of the points I discuss below. But with many cryptic species described or resurrected over the past 10-15 years, his work has the largest impact on anole taxonomy and the science that depends on it.
I’ll start with the revision of the Anolis tropidonotus complex published in Mesoamerican Herpetology (Köhler et al. 2016). Below I provide a quick breakdown of the paper. I hope that others will contribute their own views on this work in the comments. The A. tropidonotus group is one that I am well-acquainted with, having spent months of field time collecting individuals across the distribution of the group. Köhler et al. (2016) raise a subspecies (A. tropidonotus spilorhipis) to species status while describing two new species, A. wilsoni and A. mccraniei. Unfortunately, the data presented–morphology and DNA–do not appear to strongly support the recognition of any new species level taxa. I argue that the inference of four species within A. tropidonotus sensu lato should require stronger evidence than that presented.
The authors sequenced 16S mitochondrial DNA for molecular analyses and present a consensus tree from Bayesian analyses of these data. This tree recovers four well-supported and geographically circumscribed mtDNA haplotype clades that correspond with the four new species. A table following the tree reveals the genetic distances between putatively new species topped out at 4.5%. This level of mitochondrial divergence is significantly less than intraspecific variation observed in other anoles (Malhotra & Thorpe 2000; Thorpe & Stenson 2003; Ng & Glor 2011). Moreover, Köhler et al.’s (2016) sampling map reflects sparse sampling of molecular data.
Based on Figure 3, morphology (other than perhaps hemipenes, which I discuss below) does not provide any support for delimitation of those populations characterized by distinct mtDNA haplotypes. The dewlap differences reported are slight and appear to fall within the type of variation observed within and among other populations of species in this group (see photos at the top of this post for an example of two spilorhipis males that came from the same locality; photos courtesy Luke Mahler). Bottom line–we see several populations with mitochondrial haplotypes that cluster together geographically with little to no morphological evidence for divergence.
The phylogenetic and morphological patterns displayed in Köhler et al. (2016) are consistent with patchy sampling of a widespread and continuously distributed species with potentially locally-adapted populations. The authors cite “the high degree of genetic distinctiveness… as evidence for a lack of gene flow, and conclude that these four lineages represent species-level units” (Köhler et al. 2016). This assumption is questionable, as researchers have long known of the pitfalls of using mtDNA to determine gene flow (Avise et al. 1983; Avise et al. 1984; Funk & Omland 2003) and supporting evidence from morphology is lacking. The different hemipenial types represent the strongest evidence for recognizing the lineages mtDNA haplotype groups. Below I will discuss the utility of those traits for species delimitation.
Finally, the authors did not compare their purported new tropidonotus-like species to Anolis wampuensis, a morphologically indistinguishable (McCranie & Kohler 2015) form that is potentially codistributed with the new species A. mccraniei. This should have been done to avoid the possibility that A. wampuensis is conspecific with one of the newly named forms.
Another example of taxonomic inflation in Anolis is from a 2014 monograph in Zootaxa (Köhler et al. 2014).
Anolis landestoyi. Photo by Miguel Landestoy
My first encounter with the new Hispaniolan giant anole species was in December 2005, when leading a birdwatching tour west of Puerto Escondido, Sierra de Bahoruco, for a group from Scotland. Early one morning, just before dawn, we stopped at what was to become the type locality of the new lizard species and stayed for several minutes searching for some night birds (nightjars, poorwills and potoos) which are most active during crepuscular time windows. It became light, though still without sun. While standing next to the forest edge, the crawling of one of these giant lizards caught my eye. It was moving from a lower tree branch (presumably its roosting perch) towards the trunk and the treetop. It quickly moved out of view, disappearing within seconds. There were no chances for photography or capture.
One and a half years later, in May 2007, I was conducting a nest search for the endangered endemic Bay-breasted Cuckoo at the same locality. Starting at around 9 am, I hiked the trail that goes north in the bottom of the canyon, and nearly one hour later, I spotted two of these fairly large forest birds, foraging in the well wooded area. Closely and silently following the pair, I hid in a stalking manner behind vegetation and logs, occasionally getting my small binoculars out from my shirt pocket to see in detail behavioral events (feeding and mating were observed). This forest is pretty lush during the rainy season, and mosquitoes were everywhere, covering all exposed areas of one’s body. Somewhere between 11 and noon, on a sunny day, the pair seemed to have had enough activity and their stomachs may have been full (with all the cicadas around, that wouldn’t have been too hard). The birds were resting, not high in the trees, and away from sun. One of them was closer to me, well in view, and this same bird took off from its branch once, striking and trying to pull something off of a branch… It happened so fast that I could only pay attention to the bird. But my curiosity was piqued: there should be something on that branch… Binoculars out again, with cautious moves, I examined the branch. A slow scan revealed an extremely well camouflaged lizard, head facing down, that was also getting away from the sunny tree canopy. At first glance it resembled one of these large, big-headed anoles (wait, this looks like one of those barahonae-ricordii giants), but it was distinctly and unusually ashy and pale in coloration. I stared at the anole for some time, and when the birds were gone, it started moving lower down slowly. It came as close as 2 meters from ground, the right moment to attempt capture. Fortunately I had a bit of more luck than the birds had, and I captured the animal. Briefly studying the animal in hand, I noted the large dewlap and odd pattern, and took a few photos, but the lizard was faster than it looked! In a matter of seconds it quickly ran along the branch and then up the trunk and escaped!
The giant Anolis ricordii, from a population not previously reported, east of the type locality. Males are usually pale-grayish like the one in this photo.
One year later, I met some great friends and professionals. Rich Glor was visiting with some students, as was Luke Mahler and some of his (Losos) lab mates and field assistants. I showed them a photo of the animal from my laptop, that only depicted the front part of the animal (head and anterior half). They had a very tight and ambitious schedule to complete during that visit, and unfortunately they weren’t able to visit that fairly distant locality.
First photograph of the recently described Hispaniolan giant species.
The following year I was taking a workshop on natural history and scientific illustration given by the acclaimed Cuban naturalist and artist Nils Navarro, and while choosing some photos for an illustration, one from the strange anole came in view. Nils, who knows the Cuban fauna very well, immediately noted its similarity with Cuban Chamaeleolis-clade anoles. To his chagrin, I told him I hadn’t secured a specimen yet, but that I would try.
Nearly fully extended dewlap of a captured Anolis landestoyi.
No more news from the odd looking anole, until March 2010, when I had the opportunity to re-visit the locality on my own, and dedicated some time to search for the beast. After three hours of night herping, scanning many epiphytes, tree branches, twigs, vines, leaves and trunks, I found one individual, very close from the 2005 encounter! This individual was captured and photographed. The more detailed images of the new individual revealed more unique characters, strongly pointing out the argument that was in fact a new species, and its resemblance in many aspects to the Cuban Chamaeleolis-clade was already obvious. Those photos were sent to the authors, which prompted a visit by Luke.
Nearly a week later, on April 1st, Luke was already sitting at the ministry office when we first spoke by phone that day. To Luke’s unfortunate coincidence with the current date’s event, I told Luke that I did not believe that he could take a plane so fast to the DR… “Wait, what? Luke, don’t tell me you actually came all the way down here man!” Luke responded: Yes man, I told you I would.” Me: “But I couldn’t believe you were so decided, and so responsive to those photos. Luke, honestly, those were actually taken in Cuba during my last visit to the land of Chamaeleolis.” Luke: “Are you serious man? Don’t tell me that now, Jesus!”… When I was convinced he had enough torturing, I came clean and told him it was a just a joke: “Happy April’s Fools Day amigo!” Luke was still skeptical, since he wasn’t sure I was still playing the prank, nor I was just revealing that I was in fact playing a prank to him. Bad (or actually good, indeed) timing, I guess.
The senior author of the paper, Luke Mahler (left), and a local who happened to have some luck.
Luke came not only to see the specimen I had in captivity, but also to personally visit the locality and get to know the habitat and the species in the field. After several hours of traveling, we arrived just before evening, right after a light rain shower. We began our search once Luke took some habitat photos at the day’s last light. It may have taken nearly two hours to find the first one, a male that I spotted at about 1.5 m of height, head down. Luke secured a female some minutes after, and there they were, a pair of adults!
The “mystical” forest at the type locality. There are parts of this forest with plenty of the bromeliad plant commonly called “Spanish Moss.”
Finally, after some years of hard field and lab work, the species came out of the anonymity, even though it must still be hiding deep into the dense viney and undergrowth transitional vegetation of the well wooded canyon (or more technically proper, “polje”), where the spanish moss and other epiphytes hang paradoxically within the cacti and hardwood forest surrounded by the big blocks of limestone that characterize this yet remote mountain chain. Threats are not too far from this rarity: in spite of this area being protected (Reserva Biológica Loma Charco Azul), due its proximity to the Haitian border, there is intense slash and burning agriculture in the hills west, and wood charcoal is produced in large amounts and taken to Haiti where it is the basic fuel for cooking. Is the species confined to the bottom valley of this canyon? All current knowledge point it out as very possible, which would mean that the species has a very small and highly vulnerable range.
Forest burning near the type locality of the recently described anole. In the hills of western Sierra de Bahoruco.
This video was filmed and shared by Jen Moss of the Welch Lab at Mississippi State University. She observed the encounter near Preston Bay, Little Cayman, and it’s a great video showing this behavior. Lots of dewlaps, pushups, and potential exposure to predators owing to the use of a non-natural substrate. Thanks Jen!
Anolis aquaticus, the semi-aqautic anole. Photo by Lindsey Swierk
From backyard anole enthusiasts to researchers with decades of experience, dewlaps are a favorite topic of discussion here on Anole Annals. We love documenting the diversity of dewlap colors and patterns (1, 2, 3, 4), judging “best/biggest dewlap” contests (1, 2, 3), and noting dewlap oddities across the genus (1, 2, 3, 4). We’re slowly piecing together an answer to the question of what role dewlaps actually serve in signaling and, in particular, what kind of information they might convey. As you might expect, it’s a pretty complex problem, made even more interesting by the fact that dewlap information content probably reflects the unique pressures placed on individual species.
I’ve recently been working on untangling the mystery of dewlaps in a quirky species of anole, Anolis aquaticus. This water-loving anole is found along streams in pockets of southern Costa Rica and northern Panama, and it has the delightful habit of diving into water when startled. Even among the aquatic-specialized anoles, A. aquaticus is different: it tends to live in ultra-close proximity to water, preferring boulders and crevices directly in the “splash zone” instead of streamside vegetation such as other aquatic species like A. oxylophus. There’s also good reason to think that A. aquaticus has a pretty rich social life – male-female, male-male, and female-female pairs can be found within a few centimeters of each other, and often in dense groups on small rocky islands.
In light of their unusual habitat and living arrangements, we decided to explore how dewlaps correlated with multiple morphological parameters in A. aquaticus. In particular, we decided to use this species to explore a long-standing, but recently debated, paradigm that most sexually selected traits (like dewlaps) scale to body size with positive allometry – or, in other words, that they’re disproportionately large in larger individuals. Last year, we captured male and female (who lack the characteristic reddish-orange dewlap) A. aquaticus and measured multiple sexual and non-sexual traits to test this idea. Our results, available in an accepted article in Integrative Zoology, allowed us to contribute our perspective to the greater understanding of the relationship of sexual selection and allometric scaling patterns. Spoiling part of the punchline, our findings do not support the traditional idea that positively allometry is a hallmark of sexual selection.
The dewlap of Anolis aquaticus. Bar represents 1 cm.
But, equally as notable, our results also suggest some interesting features of this species, including the information content of its dewlap and how allometric patterns interact to produce sexual dimorphism. We found that dewlaps are “super-honest” signals in A. aquaticus; they could serve to amplify size differences between males signaling at a distance because of their positive allometric scaling with body size. Consequently, our study and a recent study by Driessens et al. 2015 (on A. sagrei), oppose previous ideas that dewlaps approach an asymptote of optimum size to balance the pressures of signaling with predation. Our findings are also novel in that they suggest that dewlap color (redness) may serve to convey information about male weaponry: anoles with redder dewlaps were found to have head shapes that correspond to producing greater bite force.
By comparing allometric relationships between males and females, we can also begin to identify how sexual differences in proportionality link to sexual dimorphism and ecology. For instance, male hind limb length in A. aquaticus is on average larger than that of females, but becomes disproportionately smaller as male body size increases. This opens the door to the idea that, because males are larger than females, limb length sexual dimorphism might be the result of an optimal limb-body size relationship regardless of sex; A. aquaticus of either sex with overlong limbs would probably be at a disadvantage if they needed to flee over narrower surfaces such as branches or vines.
Scaling relationships of snout-vent length and a) mass, b) limb length, and c) head length for male (closed dots, solid line) and female (open dots, dashed line) Anolis aquaticus. Axes are log scaled.
Finally, our results hint at the existence of two life-stage male morphs in A. aquaticus, as already identified in other anole species. Body scaling relationships show that small males have disproportionately small dewlaps, small heads, and large limbs, whereas large males have bigger dewlaps, bigger heads, and smaller limbs than should be expected for their body size. Taken together, these results provide a foundation for future research into “heavyweight” and “lightweight” male morphs and associated behaviors. With their small home ranges and apparently high tolerance for same-sex home range overlap, this could be an especially exciting avenue of exploration in A. aquaticus. In any case, it’s certain that there will be much to learn from this watery, elusive, semi-aquatic anole.
You can read more about this project in our accepted manuscript published online in Integrative Zoology. My co-author on this study, Maria Petelo, is an undergraduate at the University of Hawaiʻi who was supported by OTS/NSF’s Native American and Pacific Islander Research Experience, a program designed to increase the representation of underrepresented groups in the natural sciences.
Hello Anole enthusiasts. This will be a slightly different post to the usual in that Anolis won’t feature at all! I am one of those weird lizard researchers that is yet to feel the scientific attraction many of my colleagues feel towards Anolis and, as such, have always preferred their much spikier old world agamid counterparts- the garden lizards of the genus Calotes.
I’m currently doing a Ph.D. (supervised by long term AA member Adam C. Algar at The University of Nottingham, UK) that looks at how agamids use the various habitat types within South East Asia (in particular, Peninsular Malaysia), focussing on oil palm plantations, rubber plantations and secondary forests. While some agamids occupy one or more of these habitat types, only a single genus has colonised all of them- Calotes. Calotes versicolor will doubtless be familiar to any herper who has been on vacation to Southern Asia, a large, red-headed take on Anolis sagrei with the same aggressive character and, unfortunately for everything else, the same ability to dominate in invasive situations. While C. versicolor is present in human modified habitats in Malaysia, the forested North of the country is home to a larger, even spikier species: C. emma, which will occupy the forest edges that C. versicolor seems to avoid. We chose C. emma for this reason as the ability to draw comparisons between the semi-natural forest edges and man-made plantations was key to this research.
An adult female Calotes emma in a heavily disturbed oil palm plantation (photo: James J. Hicks)
We measured such Anolis study staples as body temperature (Tb), perch type and behaviour when encountered and all the usual morphology traits. We also characterised habitats structurally using random transects and thermally using ibuttons in copper models and measured thermal performance using a racetrack (not an easy piece of equipment to build in the tropics!) and HD camera.
Differences in behaviour were noticed immediately with C. emma being highly arboreal in rubber plantations (and difficult to noose!), using the smooth trunks to ascend from predators/herpers and rotating around in typical agamid fashion. In oil palm plantations the equivalent ‘trunk’ structures consisted of blocky remnants of fronds that form a hard, smooth surface that lizards tended to avoid (shame these ones don’t have toepads!). Consequently most C. emma were seen on the ground and in and amongst discarded piles of the fronds at most ca. 40 cm from the ground, using these piles as both perches and refugia. In forest edge habitat Calotes used a wide range of perches that incorporated similar heights and structures to those used in the plantation habitat but was much less abundant than in either plantation type. These behavioural differences coincided with differing femur lengths with the arboreal Calotes in rubber having the longest femurs, for their snout-vent length alongside utilising statistically wider perches.
Thermally, plantation habitats were hotter and more variable than forest edges at relevant scales to lizards as has been documented previously at larger scales. Despite this, operative temperatures fell well within C. emma’s thermal tolerances and, currently at least, seem more favourable for this species. Whether climate change will push these habitats closer to C. emma’s critical thermal maximum remain to be seen but applying the ‘standard’ 3°C rise still won’t, theoretically at least, impact their thermal performance.
In short, plantations seem to be great habitat for Calotes emma! They are extremely abundant in these man made habitats, more so than any other vertebrate species despite each plantation type seemingly forcing them to rely on different, single axes of their fundamental niche. The downside is, as always, plantations trade low abundance and high diversity for high abundance and low diversity. While rubber plantations support at least 3 other agamid species in our study area, C. emma was the sole representative in oil palm. Whether this is due to thermal aspects (is it too hot for larger-bodied forest dragons?) or structural aspects (Draco probably can’t glide onto oil palm trunks) or something completely different remain to be tested in a future session of fieldwork. This will focus on assessing the more poorly understood forest specialist agamid species’ structural and thermal niche axes and whether these requirements are met by plantation habitats.
My future fieldwork will focus on forest specialist agamids such as Gonocephalus bellii (pictured) and try to explain why they are absent from human dominated habitat types (photo: James J. Hicks)
This was a first for me: an anole with an odd, tic-tac sized growth on its lower left jaw. Though it is difficult to see in the image, there appears to be a small hole or opening in the cyst-like growth, potentially where a little sarcophagid larva will emerge from. (I’m not sure of the identity of the parasite, if indeed that is what is causing the growth – more information on the topic can be found in an older Anole Annals post).
As for the identity of the anole itself, I managed to catch a nearby individual (lacking any cysts) that I believe is the same species. It had a beautiful yellow dewlap, leading me to believe they are Crested Anoles (Anolis cristatellus).
Female Festive Anole (photo: Ambika Kamath)
Sexual dimorphism–differences between the sexes in what they look like–is rampant across animals. But how do these differences arise? Why and how might natural selection or sexual selection act differently on males and females? In a new paper from Duryea et al. (2016) published last month, we begin to see what answers to these questions look like in our very favourite organism, the festive anole, Anolis sagrei.
The data presented in this paper is unprecedented in anoles–by catching every lizard on Kidd Cay for four successive years, the authors assigned parentage to three generations of offspring, and thus assigned reproductive success to three generations of adults. Using these measures of reproductive success for males and females, they ask a straightforward question: is reproductive success correlated with body size, and do these relationships differ between males and females?
The results, however, are not straightforward: patterns of selection differ quite a bit across the three years of sampling, especially in females. But overall, we see directional selection on body size in males (bigger males father more offspring who survive to adulthood than smaller males), possibly explaining why male festive anoles are 30% larger than females.
We don’t yet understand the origins of sexual size dimorphism in anoles–why in particular, does the shape of selection on female body size vary so much? Do large males sire more offspring who survive to adulthood because they mate more often, or because their offspring are somehow better at surviving? Duryea et al. have propelled forward the state of our knowledge with a formidable dataset that raises exciting new questions.
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