Category: New Research Page 6 of 67

Emma Higgins presenting her work at Island Biology 2019

The third meeting of the nascent Society for Island Biology took place recently in stunning La Reunion in the western Indian Ocean. Conference goers were treated to a wonderful venue at the Université de La Réunion in St. Denis, whose campus looks out down the gentle slope to the open sea. Four hundred attendees from around the world reinforced what we already knew— that island biology as a study attracts a large number of researchers from very diverse fields of study. The conference organizers also are leading the way on making our meetings in remote locations more responsible; using live streaming of the sessions meant that some interested scientists could skip the travel and stay home to watch the sessions. But the real asset was that the organizers calculated the air travel carbon footprint for all attendees, finding that ~30 hectares of forest would need to be planted to offset the carbon emissions. Happily, that is exactly what they did! The conference organizers and hosts, in partnership with communities and other organizations, committed to reforesting exactly that amount in La Réunion and Mauritius.

OK, now on to the anoles! Well, given the remoteness of the meeting location (nearly the antipode of the Caribbean*) perhaps it is not too surprising that few anologists attended. But I am happy to report that Emma Higgins did, and gave an excellent presentation on her work with anoles on the island of Utila, one of the Honduran Bay Islands.

Emma is a 3^rd year PhD student in Adam Algar’s lab at the University of Nottingham, where her thesis is focused on using emerging technology to study lizard thermal biology under changing conditions (think development, climate change, and species introductions). When I say using emerging technology, I mean using #allthetech; Emma uses 3D printing, drones fitted with thermal cameras, Sentinel satellites, and LIDAR to generate her data! Her motivation follows from asking what factors control the abundance, distribution, and microhabitat of anoles on Utila, and whether these variables might be better estimated at extremely fine scales using emerging technology.

A bit of background, there are four species of anoles on Utila, including the endemics A. bicaorum and A. utilensis. An additional native species is A. sericeus, which also occurs elsewhere in the Bay Islands as well as on the mainland. The fourth species is everyone’s favorite— A. sagrei! Utila has experienced a surge of development in the last 10 years, with new roads and development going up faster than conservationists can keep track of. This is a major threat to the island wildlife, which includes an endemic iguana known as The Swamper (Ctenosaura bakeri) which favors the dwindling mangrove forests.

Emma’s work involves collecting data both at anole-level as well as above the canopy. She uses a DJI Phantom 4 drone platform fitted with a near-infrared camera to estimate a normalized difference vegetation index (NDVI, a measure of “greenness”) of the forest canopy across habitats, and found that just NDVI explains 28% of the spatial heterogeneity of lizard operative temperatures (in a mixed-model framework). This suggests that her drone can identify suitable thermal environments for lizards from above the canopy. I should mention that her resolution here is 4cm/pixel! She plans to zoom out to space and test whether similar imagery from the Sentinel 2 satellite will also be useful. Below the canopy, Emma is using LIDAR to simultaneously conduct forest shade modeling (for super fine-scale temporal variation in thermal microhabitat). LIDAR also detects perch availability, as it detects tree trunks very well. Emma also uses 3D printing to produce hundreds of anole models, each fitted with an iButton® temperature recorder and placed on perches in the forest. Each lizard print takes 52 minutes, so Emma ended up taking the printer to her flat to print 24/7 in preparation for her field season!

I should mention that Emma was joined at the conference by two other excellent scientists— lab mate Vanessa Cutts and fellow Utila lizard biologist Daisy Maryon, both of whom won awards for their posters at the conference!

Stay tuned for the announcement for the 2022 Island Biology meeting, to be held on either Mallorca in the Balearic Islands or Wellington, New Zealand. Also stay tuned for Emma’s results; we look forward to hearing more about her work!

Climate Change Will Lead to Negative Effects on Population Dynamics of an Amazonian Anole

By Luisa Diele-Viegas

On August 23, 2019

In New Research

Climate change is negatively affecting Squamates all over the world, and the perspectives for the next 50 years are worrisome. Although more than 200 studies were published in the last 20 years on this subject, only 23 present some information on Anoles, and none of them focused on population dynamics – until now. In the most recent issue of Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, Diele-Viegas et al. evaluated the possible effects of climate change on two populations of three species of lizards from the Brazilian Amazonia, including Norops fuscoauratus.

The idea of this research came from the first author, Dr. Luisa, during her PhD classes back in 2017. She was taking classes on population ecology and had the idea of to combine environmental thermal adequacy with the b-d model, which considers survival and reproductive rates to calculate population dynamics andevaluate the impact of climate change on population dynamics of her study objects, Amazonian lizards. She thus started to search in the literature for articles that focused on something like what she was thinking, and discovered that this had not been done before, at least not for squamate reptiles. She also noticed that data on Amazonian lizards’ life history is very scarce on literature, which could be a deterrent to her getting the job done. After speaking with her advisors (Dr. Fred Rocha and Dr. Fernanda Werneck), Luisa decided to estimate a tolerance index considering the relationship between the upper temperature limit of the animal activity restriction and the environmental temperature of the microhabitat in which this animal occurs and used this index as an approximation of the populations’ survival rates. This allowed her and her advisors (both coauthors of this article) to circumvent the data scarcity and put Luisa’s idea into practice, leading to the publication of this article.

Considering the tolerance index mentioned, the authors predicted that Norops fuscoauratus is likely to became locally extinct at one of the evaluated sites, Reserva Ducke, which is an almost urban reserve in the Amazonian heart. The hatchlings’ tolerance to environmental change was considered the most sensitive vital trait evaluated, highlighting the species’ vulnerability. Also, considering that the response to selection is likely to be too slow in anoles, an evolutionary change in N. fuscoauratus is unlikely to occur considering current rates of environmental change, which reinforces the species’ vulnerability at local scale. This study represents the first effort to evaluate population sensitivity to climate change among reptiles. The authors highlight the need for new studies focusing on this subject to provide theoretical and empirical basis for biologically informed conservation strategies and actions to avoid the extinction of several species around the world. Also, Luisa highlights that, as scientists, we should always value our ideas – our curiosity is the fuel that moves science into progress.

Visualising the 3D Surface Structure of Lizard Skin

By Simon Baeckens

On August 18, 2019

In New Research

Imaging the surface topography of lizard skin using gel-based stereo-profilometry.
(Baeckens et al. 2019)

The skin surface structure of lizards varies greatly among species, likely because it plays a key role in a range of tasks, such as camouflage, locomotion, self-cleaning, mitigation of water loss and protection from physical damage. Yet, we still know remarkably little about how variation in skin surface structure translates to functional variation. Part of this gap in our understanding can be traced back to the lack of means to perform high-throughput and detailed analysis of the 3D anatomy of lizard skin in a non-destructive manner.

To tackle this hiatus, I was fortunate enough to be able to round up a great team of scientists and to start exploring the possibilities of a new imaging technique, termed gel-based stereo-profilometry. In this approach, a deformable transparent gel pad with one opaque surface is pressed onto the object of interest, creating a surface impression. While the gel pad is still in contact with the object, a series of photographs from six different illumination angles are acquired, and a topographical 3D map of the surface is created by merging the acquired images using
specialized surface analysis software.

Using this technique, we successfully imaged the 3D skin surface structure of Anolis cristatellus specimens in great detail (pixel resolution of 0.86 µm) and in a short-time frame (average acquisition time of imaging and digital reconstruction combined was 90 seconds). In our new paper, we demonstrate that this technique is exceptionally useful for the rapid 3D structural characterisation of lizard skin surfaces without any specimen preparation, permitting 3D visualization in situ and even in vivo. This technique opens exciting new avenues for investigating structure–function relationships in lizard skin.

In addition to the ability to quantify the micro- and macro-structural details of lizard skin, the 3D data sets acquired using gel-based stereo-profilometry can be directly converted into surface meshes, which can in turn be 3D printed. These tangible models can then be directly employed for studies to investigate the role of scale geometry on animal–substrate interactions, or enlarged for educational purposes to illustrate key differences between different squamate taxa.

Baeckens S, Wainwright DK, Weaver JC, Irschick DJ & Losos JB (2019) Ontogenetic scaling patterns of lizard skin surface structure as revealed by gel‐based stereo‐profilometry. Journal of Anatomy 235, 346–356.

If You Thought that Brown Anoles Bully Green Anoles, You Were Right

By Nick Herrmann

On July 24, 2019

In All Posts, Introduced Anoles, New Research

Interactions between native Anolis carolinensis (green anoles) and invasive Anolis sagrei (brown anoles) in the United States are discussed often here on Anole Annals. Most recently, this blog featured a local news broadcast from Louisiana and newspaper article from Florida, both of which describe a pattern that is repeated across the southern United States: When brown anoles invade a habitat, green anoles begin perching higher off the ground and thus become more difficult for anole enthusiasts to find.

Why do green anoles and brown anoles tend to occupy different perch heights in areas where they co-occur? By far the most popular explanation is that these species partition space as a means of partitioning resources, namely arthropod food. In simpler terms, they are competitors. But competition itself is not always simple. To better understand and study competition, biologists often classify competition as one of two types. Species can compete directly via aggressive encounters (termed “interference competition”) or indirectly through their shared use of a limited resource (termed “exploitative competition”). We know that green and brown anoles eat similar prey, suggesting that their competition is at least partly exploitative. Do they also engage in direct interference?

In a recently published paper in Oecologia, Katherine Culbertson (Harvard ESPP ‘18, former undergrad researcher in the Losos lab) and I tested the hypothesis that interference competition between native green anoles and invasive brown anoles occurs in the field. More specifically, we wondered if an asymmetry in interference competition might contribute to the vertical displacement of green anoles by brown anoles. To test for competitive asymmetries between the species, we used a classic method in behavioral ecology: tethered intruder trials. We presented adult male intruders to previously undisturbed focal individuals of the opposite species and videotaped the interactions. Intruders were tied around the waist with string at the end of a fishing pole with enough slack to move freely. We analyzed several aspects of the behavior of the focal lizards to evaluate asymmetries in interspecific aggression between the species: how often they attacked, how often they displayed (throat fan extensions, headbobs, and pushups), how often they retreated, and in what direction they retreated. (Disclaimer: Whenever an attack occurred, we ended the trial immediately so no lizards were harmed.)

As anticipated, we found that interference competition is asymmetric in favor of brown anoles, which are more likely to display and less likely to retreat from interactions than green anoles. In line with their arboreal tendencies, male green anoles also trend toward retreating upward more often than expected by chance. Somewhat surprisingly, these asymmetries are prevalent despite the almost complete absence of physical attacks (there were only two attacks in nearly one hundred trials, both by brown anoles). All told, our results suggest that signaling between the species and avoidance behavior by green anoles resolve most potential conflicts before they escalate to combat.

Figure 2 from our paper, which displays posterior predictions for the (a) probability of display, (b) display rate, and (c) probability of retreat of male *Anolis sagrei* (brown anoles, “SA”) and male Anolis carolinensis (green anoles, “CA”) when presented with a male intruder of the opposite species. Brown anoles were more likely to display and less likely to retreat than green anoles.

Many Floridians I’ve met in the course of my fieldwork have described brown anoles as bullies. Although anecdotal observations of animal behavior do not always reliably represent biological truths, in this case, the collective of observations made the residents I’ve spoken with are concordant with our data. Kudos to the many local naturalists who’ve shared their stories!

In closing, I’ll attempt to refine the metaphor of brown anoles as bullies, in acknowledgement that metaphors are often imperfect and with apologies to those who bristle at any attempt to anthropomorphize non-human animals. First, what makes a bully effective? On the playground, a bully might gain a reputation as such by initiating and winning a fight. Afterward, the mere threat of physical combat is often enough for the bully to exert his or her will on others. At our study sites, where green anoles and brown anoles have co-existed for several generations, brown anoles tend to dominate interactions with green anoles without attacking them. Perhaps physical combat is more common during the incipient stages of brown anole invasion, a hypothesis which could be tested by applying our methods across sites that vary in their invasion history.

Second, what’s the best way to deal with a bully? Many children learn to ignore bullies, a strategy rendered possible by the existence of alternative space to play or activities to engage in. Green anoles appear to find refuge in the canopy, where brown anoles seldom venture. Anecdotally, areas where no such canopy exists (i.e. areas with few plants or with only short, shrubby vegetation) are the areas where green anoles are most likely to disappear entirely following brown anole invasion. This hypothesis deserves a formal test.

Special thanks to the Aquatic Preserve Program run by the Florida Department of Environmental Protection for making this work possible. Check out the paper to learn more about our methods, results, and the implications of our findings.

Katherine Culbertson marking the location of a captured green anole in the field.

Distribution Models for Puerto Rican Anoles under Predicted Climate Change

By Anna Thonis

On July 5, 2019

In New Research

SDMs for (A) A. cooki, (B) A. cristatellus, (C) A. evermanni, and (D) A. gundlachi. Left images are current suitable habitat. Right images are predicted suitable habitat in 2070 under HadGEM2-AO RCP8.5. The warmer the color (the redder it is), the more suitable the habitat.

Species Distribution Models (SDMs), although relatively new compared to other ecological methods, have been built for a wide range of taxa over a variety of habitat types and regions of the world. Given their widespread use, it was surprising to Brad Lister and me that there were very few SDMs for anoles, and in particular, none for Puerto Rican anoles. Brad and I decided to model the potential suitable habitat for all ten Puerto Rican Anolis species under various climatic scenarios for the years 2050 and 2070. The results of our study showed declines in suitable habitat for nearly all ten mainland Puerto Rican anoles with the exception of Anolis cooki. Declines in suitable habitat have the potential to substantially increase extinction risks for anoles. Although this study focused on Puerto Rican anoles, it is plausible that similar climate change impacts could be seen throughout the West Indies.

Species Distribution Modeling is a rapidly developing subfield of ecology, but we found a paucity of useful information that linked all the steps together. I am now working on a step-by-step tutorial that will fill in a lot of missing information on the steps that many tutorials breeze past. For me, an important component of creating SDMs was using software with the greatest potential for widespread use and method replication. For instance, ArcGIS is exceptionally powerful, but comes with steep licensing fees. For that reason, we opted to use comparable, open-source packages QGIS and DIVA-GIS. With respect to the actual modeling software, MaxEnt is a great option with no associated cost. Additionally, although we did not use it for this paper, Wallace is a very useful platform that incorporates different algorithms (including MaxEnt) for creating SDMs in a user-friendly series of guided steps.

As a part of my doctoral research in the Akcakaya Lab at Stony Brook University, I intend to build more accurate SDMs for Puerto Rican anoles by incorporating biotic interactions and more relevant predictor variables. I am also interested in working on SDMs that output multi-species range shifts given forecasts of future climate change. With these initiatives in mind, I anticipate reporting on new developments in Anolis SDMs in the near future. In general, the study of Anolis SDMs is just beginning and many important research directions remain to be explored. As we expand the use of SDMs I think it’s useful to keep George Box’s quote in mind: “All models are wrong, but some are useful.” It’s an informative mindset to have when building and interpreting any SDM. Although they can be helpful in conservation decision making, their results are just predictions based on more predictions and we need to keep asking ourselves how those predictions can be improved.

Evolution 2019: Patterns of Morphological and Physiological Variation of Hispaniolan Anoles

By kmwinchell

On June 27, 2019

In New Research

We all know that the anoles of the Caribbean partition the habitat based on structural environment and microclimate, leading to patterns of correlated morphology and habitat use within these ecomorphs. While we know a substantial amount about the morphological aspect of the ecomorph concept, many questions remain concerning the patterns of physiological trait evolution across Caribbean anoles and how this relates to habitat use and ecomorphology.

Brooke Bodensteiner, a PhD student in the Muñoz lab at Virginia Tech, is digging into this topic for her doctoral research. In her presentation at Evolution 2019, Brooke told us about two key questions she is attempting to address in her research: (1) Do ecomorphs overlap in physiological trait space or do they neatly differentiate into distinct groups as they do with morphology? and (2) Do thermal traits evolutionarily respond to the same microhabitat predictors?

Brooke measured thermal physiology of anoles in the Dominican Republic, including Anolis cybotes, shown here.

Brooke is investigating these questions in Hispaniolan anoles and has so far sampled 28 of the 41 species found in the Dominican Republic with representatives from all 6 ecomorphs! The Hispaniolan anoles are particularly good for this research topic since there are representatives of each ecomorph in very diverse habitats islandwide, providing many opportunities for physiological diversification. Building on a large dataset of morphological traits, Brooke collected thermal physiology data from all 28 of these species including critical thermal minimum and maximum and preferred temperature, to try to understand the patterns of physiological diversification and how they are correlated with morphological diversification.

Brooke’s results were fascinating, but more complex and nuanced than expected. Consequently, we will only tell you that her findings are intriguing and will give us a lot to ponder regarding patterns of correlated trait evolution and environmental factors driving physiological evolution. I look forward to seeing the finalized results published soon!

Evolution 2019: Dewlap Diversity and Population Genetic Structure in an Amazonian Anole

By Sofia Prado-Irwin

On June 27, 2019

In New Research

Dewlap variation in A. fuscoauratus. Photos by Ivan Prates.

One of the most well-known and “classic” anole traits is the dewlap, the (usually) colorful flap of skin under the chin that anoles use to display to one another. The dewlap plays a role in numerous anole interactions, including male-male and male-female displays of aggression or courtship. Throughout the Anolis genus, dewlap color and pattern are both quite variable. Dewlap color is thought to be a sign of reproductive isolation, and has been used by researchers to define and recognize species boundaries, although lots of variation within-species exists as well.

Ivan Prates, a postdoctoral fellow at the Smithsonian National Museum of Natural History, has been exploring this variation with the curious case of the Amazonian slender anole, A. fuscoauratus. The species is distributed throughout much of the Amazon, and different populations vary in dewlap color – some are white, some are yellow, and some are pink! Within each population, the dewlaps don’t appear to vary, but different populations have different dewlap colors, seemingly unpredictably. For example, two study populations that are separated by just 60km show different dewlap morphs, with one population having all yellow dewlaps, and the other having all pink. (Note: only males have dewlaps in this species).

This observation led Prates to two questions: first, does the phenotypic variation represent distinct evolutionary lineages? That is to say, are populations with the same colored dewlap more closely related to one another than to populations with different colored dewlaps? And second, what is driving the diversity in dewlap color?

To answer the first question, Prates performed RAD sequencing on a large number of populations throughout the range of A. fuscoauratus. Prates found a fair amount of genetics structure within the species, and identified areas that have experienced high levels of admixture as well. For example, the Atlantic Forest population and northern South American were genetically distinct, but populations within central Amazonia tend to be relatively admixed with one another. Interestingly, he found that this genetic structure of populations was not related to dewlap color at all. Populations with different dewlap colors were present within each of the distinct genetic clades. So each of the dewlap colors did not come from a single source population, and have instead diverged from one another seemingly at random.

So if the genetic structure does not predict the dewlap color phenotype, what does? Previous work on Greater Antillean anoles has shown that dewlap color and pattern vary across habitat types due to differences in light environment and visibility. Denser habitats are thought to lead to more reflective colors and patterns, while more open habitats lead to less reflective dewlaps. Prates therefore used climate data to assess whether environmental variables were correlated with dewlap color. Similar to the genetic results, Prates found no association between climate variables and dewlap color.

What about species interactions? Previous work has also shown that dewlaps can function as inter-species recognition signals. It is expected that anole species that overlap with one another should have distinct dewlaps, in order to efficiently recognize conspecifics in multi-species communities. Prates addressed this hypothesis by examining the dewlaps of other species of anoles that are sympatric with A. fuscoauratus, and assessing whether dewlap variation might correlate with Anolis community composition. Prates found limited evidence for this hypothesis – for example, in areas where it co-occurs with A. tandai, a blue-dewlapped anole, A. fuscoauratus has a fewer gray-dewlapped populations, which are more similar to blue than the yellow or pink morphs. However, Prates also found that even in sympatry with other yellow-dewlapped species, A. fuscoauratus does not have a reduction in yellow- or white-dewlapped populations.

So what is driving this dewlap diversity? So far, there’s no smoking gun, but a few suggestions come from the data. Prates plans to continue working on this question by digging deeper on both genetic and environmental scales. Stay tuned!

Evolution 2019: Comparative Landscape Genetics and Epigenetics in Anolis Lizards

By Sofia Prado-Irwin

On June 27, 2019

In New Research

The field of landscape genetics seeks to understand how patterns of genetic diversity vary across a landscape. But an organism’s traits are not just determined by their genome – they are also impacted by processes that affect the way the genome is expressed. The study of such mechanisms (i.e. heritable non-genetically based gene expression) is known as epigenetics, and has become a topic of great interested to evolutionary biologists who aim to understand the processes by which phenotypes change over time and space. Non-genetically based phenotypes can be the targets of selection, can impact the plasticity of traits in different environments, and more.

Understanding the impact of epigenetics on evolutionary processes is difficult, because it is hard to disentangle the genetic and epigenetic effects on phenotypes. Of course, epigenetics are not independent from the underlying genetic code – the genes that are expressed are a part of the genome after all. Thus because populations differ in genetic structure, it is difficult to determine whether differences in phenotypes across populations are driven by genetic changes, or epigenetic changes. To understand the influence of epigenetic changes on phenotypes, it is necessary to “subtract” the effects of the underlying genetic variation.

Ian Wang decided to tackle this problem using a well-studied Anolis species, A. cristatellus. Wang is interested in understanding what factors drive epigenetic patterns; but before understanding the factors involved, it is first necessary to describe the patterns. Wang chose to focus on A. cristatellus because it is distributed widely and throughout various environments on the island of Puerto Rico, and is therefore a good candidate for understanding how populations diverge across geographic regions (i.e. isolation by distance) and in different habitats (i.e. isolation by environment).

Wang and colleagues collected tissues from 8 localities, some of which were located in the xeric southwest, and some of which were located in the mesic interior. He performed RRBS sequencing, which captures information about methylated regions of DNA, and therefore provides information on variation in gene expression across populations (i.e. epigenetic variation). He also performed ddRAD sequencing, which captures information about genetic differences across populations (i.e. genetic variation).

In analyzing these two complementary datasets, Wang found that epigenetic and genetic distances were correlated between populations – that is to say, populations with high genetic divergence also had high epigenetic divergence. Recall that epigenetics are to not wholly independent from genetics, so this result is expected. However, each of these two types of variation – genetic and epigenetic – were also influenced by other factors.

In terms of genetic divergence, geographic distance was the strongest correlate – populations that were close to one another were more similar than populations that were further away. Interestingly, temperature and vegetation also appeared to play a role as well. In terms of epigenetic divergence, genetic distance (as represented by Fst) was the strongest predictor. Interestingly, however, vegetation was also a strong predictor as well. This suggests that on top of the genetic changes that accumulate when populations diverge, additional epigenetic shifts have also occurred, and are likely impacting the populations’ fitness in their respective environments.

These results highlight the importance of considering both genetic and epigenetic changes in studies of adaptive variation. Genomes alone may not explain the whole story! Wang is continuing this research in multiple avenues, including comparing results across species (e.g. comparing results from A. cristatellus to another trunk ground anole, A. cybotes on Hispaniola), and digging deeper into the functions of individual outlier loci from the RRBS sequencing. Looking forward to hearing more about this emerging perspective on adaptation in anoles!

Evolution 2019: Sex-Specific Mortality and Senescence in a Population of Brown Anole Lizards

By Ivan Prates

On June 27, 2019

In Introduced Anoles, New Research

Dr. Aaron Reedy presenting at Evolution 2019.

Aging theory predicts that organisms will age faster when the probability of survival to old age is low. As a result, males and females of a species may age at distinct rates if they experience different rates of mortality due to environmental factors. Postdoctoral researcher Dr. Aaron Reedy (Auburn University) and colleagues tested this idea by performing a mark-recapture study of introduced Anolis sagrei in the small Island H in Florida, an island that is approximately the size of a baseball field.

The team tracked 6,591 individuals of A. sagrei from hatchling to death through a near-complete sampling of the population four times a year between 2015 and 2019 (!!). The research group measured the body condition of individuals based on the residuals of mass on body length and estimated the rate of aging based on chromosomal telomere length from real-time qPCR.

The results suggest that males have higher mortality and shorter lifespans than females; most males die within two years, while females can live up to three and even four years. The study also found that males suffer a decline in body condition with age that females don’t seem to – Aaron even mentioned that he is often capable of predicting how old a male individual is based on how haggard it looks! Preliminary data suggests no statistical differences in telomere length between males and females, although there seems to be a trend of decreasing telomere length with age in males only.

In conclusion, Dr. Reedy and colleagues found that males have increased mortality and shorter lifespans than females, but it is unclear whether males senesce more rapidly. The next steps of this investigation will include longitudinal studies in both the field and lab to follow how fast single individuals age over their lifetimes.

You can check his poster on Aaron’s website.

Evolution 2019: Urbanization Across the Radiation

By Brooke Bodensteiner

On June 27, 2019

In All Posts, New Research

Anoles throughout the Caribbean are found in urban environments and differ in the extent to which they utilize anthropogenic habitats. There is strong phylogenetic signal in urban tolerance but is not correlated with ecomorphology of anole species. Previous work by Dr. Kristin Winchell (currently a postdoctoral researcher at Washington University in St. Louis with Dr. Jonathan Losos) and collaborators showed that Anolis cristatellus commonly uses anthropogenic perches (e.g.- buildings and fences) in urban habitats, and that A. cristatellus has repeatedly adapted to urban environments. Urban A. cristatellus have longer limbs and greater numbers of lamellae when compared to their more rural counterparts, a pattern that is repeated island-wide.

With the prediction that species within the same ecomorph class would adapt to urban environments similarly, sampling has begun with four species from the Greater Antilles. Three species belong to the trunk-ground ecomorph (Anolis cybotes, Anolis lineatopus, and Anolis sagrei) and one trunk-crown species (Anolis grahami). In the Bahamas, examining Anolis sagrei she found significant shifts in relative limb length but in the opposite direction as seen in A. cristatellus. Meaning that urban A. sagrei have relatively shorter limbs, but it is worth noting that they have longer absolute limb length along with larger body sizes. Preliminary analyses of Anolis cybotes (Dominican Republic) and Anolis grahami (Jamaica), suggest shifts in relative and absolute limb lengths consistent with the morphological differences found in urban A. cristatellus. In Anolis lineatopus, the suggested shifts in relative and absolute limb length are consistent with those shifts seen in A. sagrei.

Additionally, Kristin had all of us at the conference beat when it came to attire. Her Anolis lineatopus dress that she designed the art work for was spectacular. If you are interested in her Anolis and urban stickers and art– check out her work on RedBubble— all proceeds from her art goes to printing more stickers for outreach purposes in the communities she does her field research in.

Excellent job Kristin and we are all looking forward to learning more about this work!