Anole Urban Adaptation on the Cover of Evolution

Evolution cover may 2016

Congratulations, Kristin Winchell and co-authors!

And for those of you keeping track, that’s five anoles on the cover of Evolution in the last six years (ending a three-year drought).

Evolution covers may 2016

Incidentally, the paper  continues to attract attention, most recently in the pages of IFL Science:

City Lizards Evolved Stickier Feet, Longer Legs

May 5, 2016 | by Janet Fang

photo credit: Robert Eastman/Shutterstock

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Small tropical lizards called anoles have adapted to life in the urban jungle by evolving stickier hands and feet as well as longer arms and legs, according to a recent Evolutionstudy. These help them cling to concrete walls, walk across slippery windows, and perch on metal fences with as much ease as their forest-dwelling cousins.

Urbanization is rapidly increasing around the world, with humans living in nearly two-thirds of the planet’s terrestrial areas. As a result, animals are being confronted with new habitats – from decorative, non-native plants to impervious surfaces and artificial lights. And with these come novel selection pressures. While many wildlife species can survive in cities, relatively little research has been done on whether these populations have adapted (in an evolutionary sense) to their newfound environments.

Crested anoles (Anolis cristatellus) are trunk-ground specialists; they use their long limbs and stocky build to navigate across broad surfaces like tree trunks or the forest floor. The species is native to Puerto Rico, which has been utilized intensively for agricultural cash cops like sugar cane, tobacco, and coffee throughout the 19th and 20th centuries. This has led to massive declines in native wildlife and tree cover. Around the same time, the island underwent major industrialization: 94 percent of the 3.7 million citizens now live in urban areas.

To see if the lizards have adapted to urbanization, a team led by Kristin Winchell from the University of Massachusetts Boston compared the ecology, morphology, and DNA of hundreds of male crested anoles living in three high-density Puerto Rican cities – Mayagüez, Ponce, and San Juan – with anoles living in three subtropical forests nearby.

As predicted, the temperature, humidity, and substrate availability varied a lot between urban sites and their neighboring natural areas. Additionally, urban lizards often used artificial substrates, which were generally broader than the substrates in forests. However, city anoles had longer forelimbs and hindlimbs relative to their body size, and they also had more lamellae – tiny scales on the undersides of their toes that help them “stick” to surfaces.

The team also reared the hatchlings of wild-caught adult pairs from one urban and one natural population: 25 males and 25 females from each of the two populations. They found that the differences between urban and natural wild populations were maintained in their captive-reared offspring – which means these differences are likely genetically based.

Anole Watercolor Available on Etsy

etsy

The artist says:

“Lucky Lizard” is an original watercolor painting measuring approximately 8″x10″ and comes with a signed “Certificate of Authenticity” and packed in a clear sleeve with a backing board (unframed). Colors may vary slightly from monitor to monitor.
I use only the finest quality art supplies in my watercolor paintings – 140 lb. CP Arches watercolor paper and Winsor and Newton paints. Also, my art has been certified and accepted by the County of Kauai into their “Kauai Made” program which represents those products made on Kauai, by Kauai people.
The item will ship via USPS First Class anywhere in the world.
The story behind the painting:
This lizard is lucky because he lives in Hawaii! He is a Hawaiian anole and is often called a gecko or a chameleon even though he is more closely related to an iguana. They are found on tropical foliage and really do bring you good luck because they eat the nasty bugs.
I hope you have enjoyed the painting. Have a warm and beautiful day. Once again, Aloha from the Garden Island of Kauai!

Temporal Variation in Structural Microhabitat Use of Phelsuma Geckos in Mauritius

Phelsuma ornata

I want to start by thanking Anole Annals for the offer to write a post not about anoles, but about a group of honorary anoles, Phelsuma geckos (Losos, pers. comm.). Our recent publication (Hagey et al. 2016) looked at how Phelsuma ornata, P. guimbeaui, and P. cepediana use their environment in Mauritius over the course of the day.

Understanding how species use their environments is a fundamental step to understanding how they’ve evolved and adapted. Extensive previous work has been collecting observations and quantifying the microhabitat use of anoles and other lizards. As we all know on this blog, Caribbean anoles can be organized into ecomorphs, species with convergent morphologies and microhabitat preferences. The microhabitat use patterns of these species are so critical that the names of the ecomorphs represent their habitat preferences. After quantifying the habitat preferences of a set of species, however, often little thought is then given to how this preference may vary seasonally or over the course of a day.

Back in 2002, Luke and Lisa Harmon collected observations of Phelsuma geckos on the island of Mauritius to investigate how these “pseudo-anoles” may be partitioning their microhabitat. They found that Phelsuma partition their habitat structurally, with species using palm or non-palm vegetation (Harmon et al. 2007). In addition, Luke and Lisa collected temporal information, observing the perches that Phelsuma use over the course of the day. With these data, we hypothesized that sympatric species would have complementary activity patterns, reducing the time in which species overlap using the same perches.

We did find that Phelsuma vary their microhabitats, moving to larger diameter and lower perches later in the day, but these changes don’t reduce microhabitat use overlap between sympatric species. Alternatively, species may be moving to track sunlight for thermoregulation, following prey, or avoiding predators. These temporal microhabitat changes are likely to be important for how Phelsuma interact with their environment. We therefore feel that temporal microhabitat and activity variation should be considered more often when quantifying a species’ microhabitat preferences, as it may be an important aspect of a species’ niche (see Pianka 1973; Schoener 1974).

Hagey, T. J., N. Cole, D. Davidson, A. Henricks, L. L. Harmon, and L. J. Harmon. 2016. Temporal Variation in Structural Microhabitat Use of Phelsuma Geckos in Mauritius. J Herpetol 50:102-107.
Harmon, L. J., L. L. Harmon, and C. G. Jones. 2007. Competition and community structure in diurnal arboreal geckos (genus Phelsuma) in the Indian Ocean. Oikos 116:1863-1878.
Pianka, E. R. 1973. The Structure of Lizard Communities. Annual Review of Ecology and Systematics 4:53-74.
Schoener, T. W. 1974. Resource Partitioning in Ecological Communities. Science 185:27-39.

Carrot Rock and the Endemic Anolis ernestwilliamsi

Carrot Rock, a small protrusion of British Virgin Island, links the southern end of Peter Island to the edge of the shelf constituting the Puerto Rico Bank. This <1.3 hectare, steeply sloped island is home to two endemic squamate species: the Carrot Rock Skink (Mabuya macleani) and Ernest Williams’ anole (Anolis ernestwilliamsi). This is a somewhat surprising situation, given the proximity of Carrot Rock to Peter Island (400m) and its recent connection to the latter by a breaking shoal (water depths are but 2-3 m between the two). Hence, separation of Carrot Rock was likely recent, occurring as early as the end of the Wisconsin Glaciation (~8000 yrs ago) or at nearly any point more recently, likely within the last 3000 years (suggested by Mayer and Lazell 2000).

Carrot Rock, British Virgin Islands. This 1.3 hectare island is steeply sloped, with an elevation of ~25 m asl and a very steep aspect on all sides. There are no landing areas and the island must be reached by swimming. Obtaining a beachhead and summiting require exertion and great care.

Carrot Rock, British Virgin Islands. This 1.3 hectare island is steeply sloped, with an elevation of ~25 m asl and a very steep aspect on all sides. There are no landing areas and the island must be reached by swimming. Obtaining a beachhead and summiting require exertion and great care.

Nevertheless, morphological distinction has resulted in the specific epithets for these lizard species. The Carrot Rock Skink was described by frequent AA contributors Greg Mayer and Skip Lazell (Mayer and Lazell 2000) based on unique coloration and color pattern. The species was recognized in Blair Hedges and Caitlin Conn’s tome on West Indian skinks (Hedges and Conn 2012)–indeed, they used the node subtending M. macleani and other Virgin Island species as a calibration point. Recent analysis (Pinto-Sánchez et al. 2015) has suggested this species (along with other Virgin Island species), is (are) minimally divergent from the widespread M. sloanii complex. As the species was described based on morphology and appears to exhibit little genetic variation owing to a recent separation, species delimitation based on molecular data will surely point to collapsing these species and hence this latter finding is unsurprising.

Carrot rock is dominated by seagrape (Cocoloba uvifera) and the vine Stigmophyllon periplocifolium, with two large branching Pilosocereus royenii cacti on the crown. The majority of the anoles occur on the windward slope, where a few Cocoloba are sheltered enough to grow to heights of 1-3 meters.

Carrot rock is dominated by seagrape (Cocoloba uvifera) and the vine Stigmophyllon periplocifolium, with two large branching Pilosocereus royenii cacti on the crown. The majority of the anoles occur on the windward slope, where a few Cocoloba are sheltered enough to grow to heights of 1-3 meters.

Anolis ernestwilliamsi is very much a close relative of the widespread A. cristatellus. The endemic species is notable (and specifically recognized) largely for its increased lamellae number, color pattern, and apparently larger body size (Lazell 1983). It was described, again, by Skip, who is likely one of the few of us to have visited the island (and certainly the most frequent visitor). This description was published in Ernest Williams’ festschrift (Rhodin and Miyata 1983), in which, by my count, A. ernestwilliamsi is one of four nominate species named in honor of Ernest. As with the Carrot Rock Skink, molecular evidence suggests that A. ernestwilliamsi is minimally, or perhaps not at all, distinct from the widespread relative (A. cristatellus). Mitochondrial genetic analyses (Strickland et al., in review) demonstrate that A. ernestwilliamsi is nearly identical to many Puerto Rico Bank A. cristatellus haplotypes, suggesting a very recent maternal common ancestor (not surprising). Nuclear DNA has not yet, to my knowledge, been studied, likely owing to a lack of suitable (or available) DNA samples from the island. Concomitantly, several recent studies have demonstrated rapid evolution of key morphological traits in both Anolis sagrei (Stuart el al. 2014) and A. cristatellus (Winchell et al. 2016), including lamellae number, in response to presumed shifts in selection associated with either competitor species (Stuart et al. 2014) or non-natural substrate use (Winchell et al. 2016).

Female Anolis ernestwilliamsi. In a 1.5 hour survey around 1200h I counted fewer than 12 females.

Female Anolis ernestwilliamsi. In a 1.5 hour survey around 1200h, I counted fewer than 12 females.

Turning back to Carrot Rock itself, we might suspect that selection differs on this small island, and that selection would act rapidly in the face of the (presumably; Lazell 2005) small effective population size. This shifting of phenotype, owing to either plasticity or underlying allelic shifts, represents the processes of genetic drift and selection acting on a small population. This is an expected scenario, but leads to the question of how we like to recognize lizard species. As I teach my Zoology students, and as we all know, this is a tricky question. Anolis ernestwilliamsi is phenotypically distinguishable from other populations of A. cristatellus (Lazell, 1983). Some (myself included) might argue that this limited morphological distinctiveness is insufficiently diagnostic of speciation given the lack of genetic distinctiveness and the overall degree of morphological variation in the species. Nonetheless, some (Dmi’el et al., 1997) have examined whether the population of A. ernestwilliamsi is behaviorally and physiologically adapted to an arid and exposed habitat, implying an adaptive evolutionary response resulting in phenotypic evolution despite very recent separation and genetic similarity. That these authors found a similar physiological response (evaporative water loss rates) and that Carrot Rock is really not ecologically different from Peter Island (or most of the coastal portions of the BVI), further support the idea that the population is not terribly distinct.

Male Anolis ernestwilliamsi. In a 1.5 hour survey around 1200h I counted only 3 adult males.

Male Anolis ernestwilliamsi. In a 1.5 hour survey around 1200h, I counted only 3 adult males.

With all of this in mind, and having recently been to Carrot Rock, I remain skeptical regarding the prospects for continued recognition of A. ernestwilliamsi, despite the desire to see Ernest continue to have an Anolis namesake. Nevertheless, this should not (and indeed, didn’t/doesn’t) diminish the joy of seeing this population grasp tenaciously to existence on this speck of beautiful land.

 

 

References
Dmi’el et al., 1997. Biotropica 29:111-116.
Hedges, S.B. and C. Conn. 2012. Zootaxa 3288
Lazell, J. 1983. In: Rhodin and Miyata.
Lazell, J. 2005. Island: fact and Theory in Nature. University of California Press.
Mayer, G.C. and J. Lazell. 2000. Proceedings of the Biological Society of Washington 113:871-886.
Pinto-Sánchez N.R., et al. 2015. Molecular Phylogenetics and Evolution 93:188-211.
Rhodin, A.G.J. and K. Miyata. 1983. Museum of Comparative Zoology, Harvard University.
Stuart, Y.E., et al. 2014. Science 346:463-466.
Winchell, K.M., et al. 2016. Evolution 70:1009-1022.
[disclosure, I am an author on some of the papers mentioned in this article]

New Research on Brains and Hormones of Green Anoles

Photo from http://www.exoticpetvet.com/breeds/Green%20Anole.htm

Cornerstone recently reported abstracts from an undergraduate research symposium at the University of Minnesota Mankato. Included in the event were four projects from the laboratory of Rachel Cohen.

Seasonal Effects on Kisspeptin Concentration in the Green Anole Lizard, Anolis carolinensis

Nicholas Booker, Minnesota State University Mankato
Hyejoo Kang, Minnesota State University Mankato

 

Gonadal steroid hormones are responsible for reproductive behaviors; disruption in production of these hormones is also linked to fertility issues. The hypothalamic-pituitary- gonadal (HPG) axis controls the production of sex steroid hormones, testosterone and estradiol. A peptide, kisspeptin, stimulates this axis by acting on neurons in the hypothalamus. The green anole lizard, Anolis carolinensis, is a seasonally breeding animal that shows drastic changes in behavior and physiology between the breeding and non- breeding seasons. One such change is a large increase in testosterone levels in the breeding season compared to the non-breeding season. These fluctuations in testosterone concentration in green anoles allows for a great opportunity to study the HPG axis. In the current study, we used brain tissue from breeding and non-breeding season green anoles to perform western blot analysis on kisspeptin concentration. Due to the increase in testosterone in the breeding season, we hypothesized that an increase in kisspeptin concentrations will be observed in breeding season compared to the non-breeding season lizards. These results would suggest that kisspeptin does indeed play a role in stimulating the HPG axis and that kisspeptin could potentially be used as a treatment for infertility.

 

The Effect of Steroid Hormones on Neuronal Size and Number in Two Brain Regions Important for Reproduction

Jaeyoung Son, Minnesota State University Mankato

 

Steroid hormones, such as testosterone (T) and its metabolites (estradiol, E2, and dihydrotestosterone, DHT), are critical for the production of reproductive behavior. These hormones play a role in neural plasticity, such as changes in neuronal size change and brain region volume. Our study is examining the role of steroid hormones in maintaining the morphology of brain areas involved in reproduction, such as the ventromedial hypothalamus (VMH) and preoptic area (POA). We are using the green anole lizard (Anolis carolinensis) as a model because they are seasonally dimorphic, with more reproductive behaviors and higher steroid hormones in the breeding compared to non-breeding season. We treated our animals with different steroid hormones: T, DHT, E2, and blank capsules as a control. We collected the brains, sectioned the tissue and measured neuron size, number and density in the VMH and POA. We are expecting to find smaller and increased numbers of neurons in the animals treated with steroid hormones compared to the controls. This result would support the idea that steroid hormones are critical for the maintenance of brain areas important for reproduction.

 

Seasonal Variation in the Dorsolateral and Medial Cortex of Green Anole Lizards

Amber Day, Minnesota State University Mankato
Abdi Abdilahi, Minnesota State University Mankato

 

The hippocampus is a region of the brain involved in spatial learning and memory, and has been shown to add new neurons in adult animals. Steroid hormones, specifically testosterone

(T) and its metabolites (estradiol, E2, and dihydrotestosterone, DHT), have been shown to play a role in the addition of adult-born neurons to the brain. The green anole lizard, Anolis carolinensis, is a seasonally breeding animal that exhibits seasonally dimorphic behaviors, as well as seasonal anatomical differences in the brain. The pronounced differences between the breeding and non-breeding seasons make this lizard an excellent model for the study of how steroid hormone differences impact the brain. We examined the volume of and addition of new adult-born neurons to the dorsolateral and medial cortex in the lizard, which is analogous to the mammalian hippocampus. We sectioned brain tissue from breeding and non-breeding animals, performed a Nissl stain, and are measuring volume of the regions. We expect that the region will be larger in the breeding season due to the increase of territorial and courtship behaviors. We also treated animals with T, DHT, E2 or nothing as a control and performed an immunohistochemistry to examine how steroid hormones impact neurogenesis. We expect to see significantly more neurogenesis in the dorsolateral and medial cortex of T, DHT, E treated animals in comparison to the untreated group. Our experimental results may provide a greater understanding of the mechanisms that regulate the neural control of reproduction and territorial behaviors.

 

Amygdala Morphology and Neurogenesis in the Green Anole Lizard

Jadden Roddick, Minnesota State University Mankato
Nicholas Booker, Minnesota State University Mankato
Abodalrahman Algamdy, Minnesota State University Mankato

 

Steroid hormones and their derivatives play a major role in the reproductive system. One region in the brain that is involved in reproduction is the amygdala. We are examining the relationship between steroid hormones and neuron size, number and neurogenesis in the amygdala of the green anole lizard (Anolis carolinensis). Green anoles are exceptionally good models to examine the neural control of reproductive behaviors because they are seasonally breeding animals and exhibit unique behavioral and physiological differences in the breeding season compared to the non-breeding season. These behavioral differences are likely caused by seasonal changes in circulating steroid hormone levels. For our project, breeding green anole males were gonadectomized and a capsule containing testosterone, estradiol, dihydrotestosterone or left empty was inserted under the anole’s skin. The animals were injected with bromodeoxyuridine (BrdU; a new cell marker) for three days after the treatment. After one month, brains were collected, sectioned, and placed on slides. An immunohistochemistry for BrdU and Hu (neuronal marker) was conducted to examine the presence of new neurons in the amygdala. Alternate sections were Nissl stained and used to count cell number and measure soma size. We expect to see a decrease in neuron number, soma size, and neurogenesis in the animals treated with hormones compared to the animals treated with the blank capsule because we see this pattern in breeding season animals. This work will help provide more insight into the neural control of reproduction.

 

Are Anoles Evolutionarily Adapting to Urban Habitats?

kristin winchell paper AA post

Photo by K. Winchell

In a global change scenario, the persistence of numerous animal populations is challenged by the consequences of human activities. Urbanization, for instance, represents a dramatic habitat transformation that has led to a general pattern of reduced biological diversity in these areas. Paradoxically, some species are doing very well in these new environments. This leads to the question of whether and how these populations are adapting to these new environmental conditions.

Although the number of studies providing evidence for phenotypic differences between urban and natural areas is growing fast, few studies have investigated whether and how animals might be evolutionarily adapting to the intensively modified urban habitats. Kristin Winchell and collaborators address this question in their recent publication in EvolutionPhenotypic shifts in urban areas in the tropical lizard Anolis cristatellus.” The authors studied the habitat use and morphology of forest vs. urban populations of Crested Anoles, Anolis cristatellus, from three municipalities in Puerto Rico. In short, this article provides evidence suggesting that urban anoles are under differential selective pressures as compared with those from forested habitats, and that these differences may have a genetic basis.

As the authors detail in their paper, anoles are a great system to study the morphological consequences of urbanization. This is because much information is available on the relationship between their habitat use, morphology and performance (reviewed in Losos 2009). In urban habitats, natural substrates have largely been replaced by artificial structures such as metal poles and walls. Consequently, it can be predicted that their performance on these surfaces is not optimal, as their morphology may not be suited to use these substrates. Indeed, it has been shown that lizards tend to perch on narrower, less smooth surfaces in natural habitats –a topic that has been dealt with in previous AA posts.

In this paper, the authors use field observations to show that lizards in urban areas use artificial substrates a large proportion of the time and that these urban substrates are broader and smoother than those in natural areas. Then, by X-raying lizards from the different habitats, the authors show that urban lizards have longer limbs (relative to their body size) and higher number of subdigital lamellae -which improve traction for perched lizards- than individuals from forested areas (Fig. 4). This is indeed consistent with ecomorphological predictions that anoles with longer limbs perform better on wider perches. Increased lamellae number should provide lizards with a better grip on smoother surfaces.

Fig. 4 from Winchell et al. (2016). This -really cool- figure shows how urban and natural populations differed in key morphological variables: (a) subdigital lamellae number and (b) limb length

Fig. 4 from Winchell et al. (2016). This -really cool- figure shows how urban and natural populations differed in key morphological variables: (a) subdigital lamellae number and (b) limb length

Finally, the authors conducted a common-garden rearing experiment in which they reared individuals from one of the three pairs of populations studied. The aim of this experiment was to rule out the possibility that morphological differences are merely the consequence of phenotypic plasticity. When measured at approximately one year of age, the first generation offspring of urban lizards showed longer forelimbs and more lamellae as compared to offspring of forest-dwelling lizards (Fig. 5). This result suggests that anoles in urban areas are under significantly different natural selection pressures and may be evolutionarily adapting to their human-modified environment.

Fig. 5 from Winchell et al (2016). Offspring reared in captivity showed the same trend as wild-caught populations of more subdigital lamellae and longer forelimbs in urban individuals: (a) relative limb length and (b) subdigital lamellae number

Fig. 5 from Winchell et al (2016). Offspring reared in captivity showed the same trend as wild-caught populations of more subdigital lamellae and longer forelimbs in urban individuals: (a) relative limb length and (b) subdigital lamellae number

References:

Winchell, Kristin M., Reynolds, R. G., Prado-Irwin, Sofia R., Puente-Rolón, Alberto R., and Revel, Liam J. (2016). Phenotypic shifts in urban areas in the tropical lizard Anolis cristatellus.

Kolbe, J.J., Battles, A.C. & Avilés-Rodríguez. K. (2015) City slickers: poor performance does not deter Anolis lizards from using artificial substrates in human-modified habitats. Functional Ecology.

Losos, J.B. (2009) Lizards in an Evolutionary Tree: Ecology and Adaptive Radiation of Anoles. University of California Press, Berkeley, CA, USA.

Advice Needed on Hatching an Anole Egg

Anole egg from http://www.anoleimaging.com/Anoles/ag_16_egg2.html

A concerned Anole Annals reader writes in:

My dog just violently chomped  a female alone. Along with her entrails protruding from her body we two eggs. One was small, under-developed the other was the size they are laid. I have at the time done my best to put it into a container and emulate the  same conditions outside ( I live in Florida) with  dirt, leaf litter (small) moisture and heat. I removed the placental outer membrane which would have been separated if she had laid. I feel terrible my young and excitable dog did this. Is there any hope?

Can anyone advise?

Localities for Anolis lemurinus in Costa Rica

Hello AA readers! I’m writing today with a favor to ask. I’m planning to do some research on Anolis lemurinus in Costa Rica this summer, and I’m looking for potential field sites. I’ve been to La Selva Biological Station, which seems to have a healthy population, but if you know of any other localities in Costa Rica where A. lemurinus are abundant, please let me know! I’d greatly appreciate it.

Please contact me at pradoirwin [at] g.harvard.edu

Thanks!

 

Whooping Crane Eats Anolis Lizard

Egret and maybe anole

We’ve come to realize, sadly, that just about everything will eat anoles. Birds are particular culprits and we’ve seen some horrifying examples of egrets downing the little green and brown fellows. Now comes a report that a whooping crane, of all things, will also indulge.

Vladimir Dinets–he of crocodilian behavior fame (check out his awesome book, Dragon Songs )–reported on dietary observations a reintroduced population of cranes in Louisiana. The anolivory represents the first instance of whooping crane predation on a lizard (but not on a squamate, as the photo above attests).

 

Aquatic Anole Sleep Site Fidelity

small anolis aquaticus 6

Juvenile Anolis aquaticus wakes up for science, Photo: Jonathan Flanders

One of the many wonderful things about anoles is that anole-hunting can be a 24/7 experience, as many nocturnal Anole Annals adventurers have shown and I’ve noted before. As an undergraduate, I spent many days and nights scanning trunks, leaves, sticks, bushes, etc. for anoles — a habit that got so ingrained that I still do it while hiking around northern California. So, logically, when I found myself in Costa Rica for the last field season of my Ph.D. (which is on bats), I had to do some lizard spotting, if only to remind myself of the good old days when I studied animals that don’t fly or bite. (Ok, anoles bite but that’s what makes them such great fashion accessories.) As I was already up until all hours of the night, I decided to check out where anoles were sleeping. There happened to be a small group of aquatic anoles living near my cabin and I (along with my batty colleague) noticed that each night they seemed to be in the same place — one email to Jonathan later and we wrote up a short note for Herpetological Review about sleep site fidelity in Anolis aquaticus.

small aquaticus 2

Who turned the sun on? Photo: Jonathan Flanders

We observed the lizards for 16 nights over a period of 24 nights and found that of the six individuals, they were in the same place almost 80% of the nights, which is very high compared to what has been found in some other species. All of the lizards were perched in such a way that they were either obscured from view or had easy access to water to escape from predators. The area was particularly dry at that time so this may have reduced the number of suitable sleep sites for these aquatic lizards or maybe aquatic anoles are just pretty faithful to their sleep sites. In any case, it was a lot of fun to go back to my lizard-y roots and find some sleepy anoles.

 

 

Green and Brown Anoles Living in Harmony on Little Cayman

Photo by Pat Shipman

Photo by Pat Shipman

We’ve often commented on the interactions between the green anole, Anolis carolinensis, and the brown anole, Anolis sagrei. We’ve also had periodic posts from Pat Shipman on Little Cayman, who moonlights as an anthropologist and science and history writer when not watching anoles.

Here’s further evidence that greens and browns can coexist: A. maynardi (a relative of A. carolinensis) and A. sagrei side-by-side, ten feet up on a wall.

Rapid Evolution to Urban Environment in Puerto Rican Anoles

From New Scientist:

Lizard on reddish wall
Clinging on with ease

Kristin Winchell

City living comes with unique challenges. If you’re a lizard, scaling a windowpane without sliding off is one of them. One lizard has already evolved traits to help it do just that.

“Urban areas are just another environment. The animals that live there aren’t somehow immune to natural selection,” says Kristin Winchell of the University of Massachusetts Boston.

Her team compared males of the anole lizard (Anolis cristatellus) in the Puerto Rican cities of Mayagüez, Ponce and San Juan with those in nearby forests.

They found that city lizards regularly clung to objects like walls and windows, proving that they use the full urban environment instead of restricting themselves to wild patches more similar to their forest roots.

Compared with forest-dwellers, city lizards had longer limbs and more lamellae – scale-like structures that help their toes stick to surfaces. These traits probably enable them to stay attached to slippery urban perches. “I chased a lizard that ran straight up a window 30 feet and was out of reach in 15 seconds,” says Winchell. “I couldn’t catch this well-adapted lizard.”

The team also raised urban and forest lizards from the Mayagüez region in the lab and found that differences in limb length and scale number remained, suggesting a genetic basis to the urban lizards’ abilities.

The anole frequently wows scientists with feats of rapid evolution in natural environments. The new finding suggests that this capacity applies to cities as well.

Other urban animals also adapt. We know, for example, that birds alter calls to be heard over city noise and leafcutter ants adapt to elevated temperatures in an urban heat island.

But well-studied examples are rare. “Urban evolution is a really young field,” says Winchell.

Evolutionary biologist Jason Munshi-South of Fordham University in New York agrees. “There aren’t many documented cases of urban evolution yet, but people are going to start looking for them in earnest,” he says.

Munshi-South believes Winchell’s study is an excellent addition to this emerging field. “The next step,” he says, “which I’m excited to see them do, is to identify the genes underlying these adaptive traits.”

Winchell says that, ultimately, understanding urban adaption could help conservation. “Having a grasp on which animals tolerate urbanisation gives us a better idea of which ones we need to focus on when preserving natural habitats,” she says.

Evolution, DOI: 10.1111/evo.12925

Anoles of Luquillo, Puerto Rico: ID Help

I did a bit of herping in Luquillo on the northeast coast of Puerto Rico and the abundance of anoles and frogs  was incredible. I was hoping for help IDing these guys and any insight you might have on these species. I think the first three are the same species?

  1. We found this sleeping anole perched up on the back of a sign.

Luquillo

2)    Anole, Luquillo

3)        Luquillo

4)

Luquillo

5) Luquillo

6) This last one was found in the Yunque, not in Luquillo. Not the best photo, but it was a beautiful anole.

anoleYunque

Thanks again!

Gentle Gorilla Befriends Green Anole

The Dodo provides the full details, but here’s the gist: “I was at the zoo watching the gorilla exhibit [at the San Diego Zoo], and that little lizard came up and just froze when the gorilla started playing with it. He picked it up by the tail a few times, poked at it, but never killed it.”

As Yoel Stuart reported previously in AA‘s pagesAnolis carolinensis has become established at the San Diego Zoo. Who knows which of the zoo’s denizens will be the next to adopt an anole?

Age- and Sex-Specific Variation in Habitat Use by Brown Anoles

Little guys like it narrow. Photo from Daffodil’s Photo Blog.

The influence of habitat use on ecological and evolutionary patterns in Anolis lizards is well documented. Despite extensive work on interspecific variation, how habitat use varies within a species is relatively understudied.

As part of my master’s work in Dan Warner’s lab, we caught and recorded the perch height, width, and substrate (i.e., ground vs. vegetation) of 717 brown anoles (A. sagrei) on a small island in the Halifax River, near Ormond Beach, Florida. The island consisted of two main habitat types (open-canopy and forest) with an intermediate between the two.

Continue reading Age- and Sex-Specific Variation in Habitat Use by Brown Anoles

Teaching Kids How To Dewlap

Anolis lizards have established their place in the annals of college textbooks. There are also a growing number of resources available for elementary and high school teachers to bring the biology of anoles into their classrooms as well. The Howard Hughes Medical Institute (in collaboration with Jonathan Losos) developed several online modules around anoles: one on the diversity of Anolis lizards, another on speciation, and a virtual lab integrating those topics. Michele Johnson also has several classroom exercises on here website, LizardsandFriends.org, some of which have been discussed on AA previously (here and here). I am writing today to share another exercise with our readers that was a recent success with a group of young scientists-to-be.

Dewlapping fifth graders at GEMS 2016

Dewlapping fifth graders at GEMS 2016

I recently introduced Anolis lizards to a group of fifth and sixth grade students at a conference aimed at getting young girls interested in the STEM professions. With around 130 girls learning about topics ranging from gemstones, programming, seeds, and urban wildlife the event was a undeniable success. My session introduced the diversity of topics that our community addresses with Anolis lizards. After explaining to students how they could figure out what lizards are anoles at the local pet stores (dewlaps and toepads), I used anoles to demonstrate how animals can communicate without talking. My exercise amounts to a game of charades where the students have a dewlap, a display-action-pattern, and a key representing four species from Puerto Rico (thanks to Travis Ingram). The display patterns are not as complex as real dewlap displays, but were made to allow the students to easily act them out and distinguish between the patterns and it worked great. The kids thought this was a lot of fun and it gave me the opportunity to pepper the discussion with additional comments about animal communication. I originally designed the exercise for fourth through seventh graders, but a curious three-year-old played along just as well during one session. I would be happy if other people used this exercise for their own outreach activities. It can be downloaded here.

In closing I will add that the students were impressed by the brown anole I brought with me. I imagine I would have left a more lasting impression if I brought a knight anole. Things to remember for next year.