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.
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.
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?
We found this sleeping anole perched up on the back of a sign.
6) This last one was found in the Yunque, not in Luquillo. Not the best photo, but it was a beautiful 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 pages, Anolis 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?
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.
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
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.
This video, shot by Johann Prescher, is of an Anolis lineatus from Curaçao, gracefully jumping from one tree to another. Note, however, what it does just as it lands, pulling up its forebody to contact the trunk with all four legs simultaneously, like a flying squirrel. The mechanics of jumping in anoles have been well-studied, but the mechanics of their landing, not so much. Good research project waiting to be done!
At the other end of the world in the Indo-Malayan realm (in India, down south in the sky islands of Western Ghats), a Calotes rouxii male is advertising itself. He is displaying his bright red head on its black body. Even the dewlap region is almost black. Facial region is almost completely bright red along with nuchal and spinal crest. Male display of this lizard is like many Anolis sp. A male typically does some pushups , ducks and bobbles his head to display his dominance in physical prowess and colour.
A letter in Anole Annals’ inbox. Can anyone help?:
I am a student from xxx High School in New York. As a science research student interested in phylogeny of squamata, I have come across Bayesian Inference quite a lot. I have spent a lot of time researching bayes theorem and how it relates to phylogeny, but have yet to find an article that makes sense to me as a sophomore in High School. Do have an explanation to bayesian inference and how it used in phylogenetic research? Being interested in phylogenetics, I have looked into researching phylogenetic relationships of Pogona based on molecular data. I have yet to find a taxonomic revision of Pogona, the latest one I found only used morphological data, Taxonomy of Pogona (Reptilia: Lacertilia: Agamidae) by Witten in 1994. Do you think this would be a good topic for me? In addition to selecting genera to study, I have had trouble understanding the methodology that goes into phylogenetic studies. For the most part the methodology resembles collecting DNA data through PCR, then bayesian analysis is run using MrBayes. Can you explain to me the process of choosing primers for use in PCR? Can you explain what and how data is inputted into MrBayes? Would you or anyone you may know possibly be interested in assisting me with my research in the phylogeny of squamates?
We just wrapped up our Anole March Madness tournament in which we brought to you many fictional battles of mainland and island anoles. We researched each species included in the tournament and highlighted some little-known facts about the participants. We told you about dewlap colors, ecomorphs, habitat use, invasion, body patterns and colors, and much more. But finding this information for each species was more challenging than we originally expected. The state of anole knowledge is certainly imbalanced.
Looking at the number of Google Scholar citations for each species shows just how imbalanced our knowledge of different species of anoles is. Of the species we included, only three of the mainland species had more than 200 citations and none had more than 600. In contrast, of the island species, six had more than 200 citations and Anolis cristatellus had a whopping 1230 citations! Within regions there is quite an imbalance, too — check out how many more studies there are on Central American species compared to South American species (orange and red) and on Greater Antillean species compared to Lesser Antillean species (light and dark blue). This is perhaps unsurprising to many. We all know that anole research tends to be biased towards Caribbean species, but it was surprising to me how large this bias is!
This gives a sense of how much information is available for the species we highlighted in our tournament. For a few species, we were not even able to find photos (at least with appropriate usage rights) and for many the only information we could find was native range, color, and body size. For example, Anolis placidus had only five Google Scholar citations to go by, few images (other than specimens), and really no ecological information other than its ecomorph. But it must be named the “Placid Anole” for a reason, right? So we ran with that. Even with the paucity of information for some species, we were able to piece together some interesting stories highlighting some of the unique adaptations, ecology, and morphology. Here are some of my favorites with links for more information.
Anolis aquaticus and Anolis macrolepis were our two representative aquatic anoles. These species are adapted to streamside living, using the boulders as foraging grounds and for quick escape from predators–swimming, running across water, and even remaining submerged to get away from a threat! We used these behaviors in our stories–allowing both species to have sure footing in their stream side home and escape into the water when necessary.
Another unique anole we featured was Anolis onca, the only anole to have lost its toepads entirely. Anolis onca is adapted to a beachy life, making its home in sandy substrates and perching on bushes. We played this as a strength in round 1. It’s not clear what the functional reason for the loss of lamellae is–as has been suggested on Anole Annals, perhaps the sand renders lamellae or setae useless. The reasons for this morphological outlier are yet to be explored, but we figured A. onca must have an advantage in the sand over other anoles!
A crowd favorite from our tournament, but alas not the champion, was the only completely blue anole: Anolis gorgonae. This anole didn’t make it too far in our tournament because his bright blue body made him extremely visible on the forest floor. The blue may help camouflage them way up in the canopy, but it seems that down low they are visible against the green leaves from a distance. We wanted to root for him too, but how does something that visible not get eaten to extinction?
And finally, we made sure to feature a few of the anole kings: the crown giants. We know our readers here at Anole Annals love their giant anoles. These monsters of the canopy seem like they could beat out just about anything (or eat them!), and so it was in our tournament. In the end it was too tough to decide between the beloved Anolis equestris and the lesser-known giant of the mainland, Anolis frenatus. And so we enlisted the help of the mainland-island competition vs predation debate (reviewed in Losos 2009 – p.159) and had a monkey swoop in to help us decide (yes, this happens!). We wondered, could the predator-naive A. equestris establish itself in a land full of predators like the forests of South America? Despite being successful at invading Miami and some other Caribbean islands, it doesn’t seem to have established itself in South America… yet.
On behalf of all of the contributors to Anole March Madness 2016 we thank you for playing along with us. We hope to bring you another tournament next year, so let us know if you want to help make that happen!
I just got back from a trip to the Bahamas with Losos lab post-docs Anthony Geneva and Alexis Harrison, accompanied by expert lizard catchers Inbar Maayan and Sofia Prado-Irwin (Harvard graduate student). We parted ways for the first few days of the quick trip, with Anthony and Sofia headed to Bimini and Alexis, Inbar, and myself on Abaco. Read more about the Bimini trip in Sofia’s recent post.
Friends for the Environment Kenyon Center field station
On Abaco, we stayed at the brand new Friends of the Environment Kenyon Center. We were really impressed by the great accommodations of this field station. The station was sustainably built and had all the modern amenities we could wish for. The field lab was large and equipped with microscopes and plenty of counter space. We were equally impressed by the staff and their outreach efforts. The Friends for the Environment does a fantastic job providing nature education to local kids from age 3 through college! Their ambitious organization seeks to provide high-quality and low-cost facilities for visiting scientists and to provide outreach and education to the local community. We spoke with the coordinators of the organization who told us that any time researchers are looking for extra hands in the field they are happy to arrange local students to assist. We strongly encourage others traveling to Abaco to stay here!
“In the end we will conserve only what we love, we will love only what we understand, and we will understand only what we are taught.” – Baba Dioum (posted at the Friends for the Environment)
Our main goal on this trip was to capture Anolis sagrei to continue ongoing research into the amazing diversity among islands in this species. We were immediately struck by how much smaller the Anolissagrei on Abaco were compared to those on the other islands we have been to. I was also struck by how many A. sagrei used the ground. I normally study Anolis cristatellus, and although they are the same ecomorph, I rarely see A. cristatellus on the ground. I also don’t recall seeing A. sagrei frequently on the ground on Bimini or Eleuthera. So observing these lizards, particularly the females, on the ground at such a high frequency (they literally scattered as I walked!) was very surprising. Is this common on other islands with A. sagrei and I just haven’t noticed before?
As with any good field trip, we also encountered a great diversity of herps. Although the only native anole to Abaco is A. sagrei (according to Powell and Henderson 2012), we also saw plenty of Anolis distichus and a few Anolis smaragdinus. We also saw the invasive Cuban tree frog (Osteopilus septentrionalis), the native Eleutherodactylus planirostris, and plenty of curly-tails (Leiocephalus carinatus). No live snakes to report, although we did come across a couple of roadkill Cubophis.
Although we found no Sphaerodactylus, we did find plenty of non-native Hemidactylus. Interestingly, Hemidactylus is not listed in Powell and Henderson’s (2012) list of West Indian amphibians and reptiles for Abaco. Can anyone ID this species (the photos are of two individuals) and tell me if this has been reported before for Abaco? Obviously Hemidactylus are widespread in the Caribbean, but I was surprised to see it absent from the species list for many of the Bahamas islands.
If you missed the live Twitter broadcast of the final round, here it is: the conclusion of Anole March Madness 2016. In the final round, Anolis equestris represented the island anoles and Anolis frenatus represented the mainland anoles to answer the question every anole biologist ponders: are island anoles or mainland anoles superior?
In recent months, there has been a lot of talk on the Auburn campus about multimodal signals. Diana Hews gave a phenomenal seminar to the Biology Department last November about complex signaling in Sceloporus lizards, and just last week Eileen Hebets told a similar story about signaling behavior in a group of invertebrates, amblypygids. The latter lecture prompted a momentary side conversation between a Warner Lab postdoc, Tim Mitchell, and me concerning the apparent lack of multimodality in Anolis signaling. Ironically, I just ran across a 2016 publication by Baeckens et al that forced me to eat crow, albeit only a tiny bit of crow.
Anoles, like most iguanians, have been labeled as “visual only” signalers and for good reason. Anoles lack the epidermal glands that secrete the typical chemicals used in lizard chemosensing. Rather, anoles are known widely as models for communication for their reliance on visual signals (which have been demonstrated to be quite complex despite being unimodal) and are also characterized by a low baseline rate of tongue-flicking, even when considered against the backdrop of other visually oriented iguanians. Additionally, previous experiments conducted with A. carolinensis found no significant evidence of chemosensory function in prey selection, assessment of opponents, or in mate choice (Jaslow & Pallera, 1990; Forster et al., 2005; Orrel & Jenssen, 2002). The question of whether or not anoles utilize chemical signals seems to be one answered; however, Baeckens et al have conducted a simple but convincing study that might demonstrate the converse. Continue reading This Anole’s Signal is…Multimodal?→
I recently accompanied postdoc Anthony Geneva on a collecting trip to the small Bahamian island of Bimini for the shortest field excursion I’ve ever been on – four days in total. We were there to collect animals for a breeding colony, and luckily for us, the abundance of anoles on this tiny island is unbelievable. There are four species of Anolis present, each one representing a different ecomorph. Unsurprisingly, the brown anole A. sagrei is by far the most common, but we also saw our fair share of trunk-crown green anoles (A. smaragdinus), trunk anoles (A. distichus), and even a good number of twig anoles (A. angusticeps), which are notoriously hard to spot, so we were pretty excited. The island is also home to healthy populations of curly-tailed lizards (Leiocephalus), whiptails (Ameiva), and several species of gecko, so there was lots to see.
We collected during the day and at night, and were amused by the behavior of some of these lizards. My favorite find was this little guy sleeping under a leafy blanket. He almost fooled us, but that little curl of tail poking out gave him away.
We were also lucky to witness an adult angusticeps in broad daylight, the first time either of us had ever spotted a twig anole during the daytime. In true twig anole fashion, he kept subtly repositioning himself around the branch to hide, making it rather annoying to photograph him. Nonetheless, it was an exciting find.
Anolis angusticeps, taken by Anthony Geneva
On the other side of the spectrum was this very bold smaragdinus¸ who jumped from a leaf above and stood right next to me, giving me some solid side-eye before running back up the trunk.
For a quick four-day trip, we saw a really remarkable diversity of lizards, and we had a great time on Bimini.
Our (fictional) anole tournament is nearing its end. The two semi-final matches concluded leaving only two anoles remaining. Who will be the ultimate champion, an island anole or a mainland anole?
Here’s the recap of the Final Four:
Winner match 25 (Anolis aquaticus) versus winner match 26 (Anolis frenatus) In the rainforests of Columbia, Anolis aquaticus has ventured slightly out of his native range. Skittish from his previous streamside encounter with the giant Anolis insignis, he warily watches the canopy despite coming out on top in his last battle against Anolis limifrons. He is no stranger to Anolis frenatus, whose range extends north into Costa Rica, yet he fails to recognize the danger he is in as he climbs a tree towards a swarm of tasty insects. Out on a branch 10m up A. aquaticus gorges himself on the abundant food that tasted so much better than the streamside meals he was used to. Out of the corner of his eye, he sees the imposing form of Anolis frenatus move. More than twice his size, A. frenatus is a sight to behold. Anolis aquaticus quickly surveys his escape options. Seeing a stream below he rationalizes that he can escape if need be. He continues to gorge himself. Anolis frenatus is taken aback at the impertinence of this newcomer. He makes his way towards the branch upon which A. aquaticus is perched. Not willing to abandon his smorgasbord, A. aquaticus boldly stands his ground. He turns to face A. frenatus and begins to dewlap; perhaps this is a friendly giant that will want to avoid conflict. Anolis frenatus stops to size up this intruder and quickly determines that this tiny anole poses no threat to him. Anolis frenatus does not even bother to dewlap back. He continues on his path towards Anolis aquaticus, who stubbornly continues to dewlap and push-up in his cloud of tasty morsels. Anolis frenatus lunges at A. aquaticus, who instinctively turns and leaps without looking towards the stream. Anolis aquaticus sails through the air and lands safely in the water, or so he thinks. As he climbs onto a boulder, a fish-eating spider (Trechalea spp.) with a body size of nearly 17cm seizes the opportunity and leaps onto the unsuspecting and soggy anole. The spider makes quick work of the aquatic anole. Anolis frenatus watched from his high perch with a mouthful of delectable insects which he incidentally gobbled when he leapt at A. aquaticus with mouth agape. Anolis frenatus revels in his glory as he watches his competitor meet his end below. ***Anolis frenatus wins***
Winner match 27 (Anolis equestris) versus winner match 28 (Anolis bimaculatus) A hurricane of unprecedented proportions has just ripped through the Caribbean. The Cuban Knight Anole, Anolis equestris, and the Panther Anole, Anolis bimaculatus, both find themselves washed up on an unfamiliar low-lying island. The waves periodically break over the island, washing away the debris on the ground. Both lizards quickly find a perch and scramble to escape an incoming wave. As the reach safety atop their scrubby perches, they catchy sight of each other. Clearly this island refuge has room for only one of them. Two lizards enter, one lizard leaves on this subsiding volcanic dome. They lock eyes and begin to dewlap. Nearly evenly matched it’s not clear who will claim this island as his new home. Anolis equestris extends his dewlap first. He unleashes a flurry of push-ups and rapid flashes of his cream colored dewlap. The slightly smaller Anolis bimaculatus has no choice but to stand his ground. He strains to extend his orange-yellow dewlap as far as he can. Unfortunately, his species has a disproportionately small dewlap for their size, and this A. bimaculatus is average sized at best. Anolis equestris, completely and utterly unimpressed, leaps from bush to bush with waves breaking over the rocky ground below him as he heads towards A. bimaculatus. Anolis bimaculatus makes an offensive move and lunges at A. equestris, who has by now reached the neighboring bush. Anolis bimaculatus lands a calculated blow on the abdomen of A. equestris. Despite the searing pain in his kidney, A. equestris reaches around and snatches A. bimaculatus in his forceful jaws. In one quick motion, A. equestris flings the slightly smaller A. bimaculatus over his shoulder and off the perch. Anolis bimaculatus hits the rocky ground and begins to sprint toward the nearest bush. At this moment a large wave crashes over him and carries him off the low-lying island. Anolis bimaculatus scrambles onto a floating log, but is immediately caught in the outgoing rip and is carried far into open water within moments. Anolis equestris watches A. bimaculatus ride the waves out of his life and weathers the remainder of the storm safely on his elevated perch, alone. ***Anolis equestris wins***
Which brings us to our dramatic conclusion: Anolis frenatus, representing the mainland, versus Anolis equestris, representing the islands!
Here’s what you missed in the Elite 8 round: Anolis aquaticus proves he’s in it to win it when he battles Anolis limifrons; Anolis proboscis wonders what his proboscis is good for as he battles the giant Anolis frenatus; Anolis equestris shows Anolis porcus who the king of the jungle is; and the big-cat-lizards Anolis marmoratus (AKA Leopard Anole) and Anolis bimaculatus (AKA Panther Anole) face off. Continue reading Anole March Madness: Elite 8 reduced to Final 4!→
“This is not a Spring Break trip to Costa Rica, it is a herpetology class trip to Costa Rica that happens to be over Spring Break.” So said Jonathan Losos to a room full of eager students, many of whom had chosen to take Herpetology in part because of the adventure that awaited them. As first year Ph.D. students in the Losos lab, we were as excited as anyone for the opportunity to see some of Costa Rica’s rich biological diversity. Plus the well-publicized stereotype of how young people spend Spring Break has never really appealed to us. We’d rather be in the nighttime forest with a headlamp.
The lichen anole, A. pentaprion
The trip started with a day and a half at Veragua Rainforest. We saw tons of frogs and a handful of snakes, but anoles were hard to come by except for a few individuals along shallow, slow-moving streams (A. humilis, A. limifrons, and A. oxylophus). One of our most exciting finds of the trip was along one of these streams – an A. pentaprion hugging a narrow stem at eye level. It was shocking to see this lizard so close to the ground as it is often found high in the canopy and has even been observed gliding between perches. While many mainland anoles don’t fall clearly into the classic ecomorph categories, this lizard, with its small legs, long body and head, and slow but sneaky evasive behavior, is very reminiscent of West Indian twig anoles (and he’s got a gorgeous dewlap too! see photo at end of post).
I am very interested in IDing the following anoles I saw on the island of Culebra, which is 17 miles east of Puerto Rico. I thought I would be able to find a guide to anoles of this area online, but IDing them turned out to be harder than I thought. Thank you for your time!
1) First one was found in the parking lot of Flamenco.
2) Also found near Flamenco.
3) Found in town. Bright yellow dewlap.
4) Found in town.
5) Found in town.
6) Found in town. Dewlap was dark orange with yellow near the throat.
Our (fictional) tournament of anoles is well underway as we complete the Sweet 16 round! The competition was tough and a few favorites fell from glory (sorry!). We’ve been repeatedly asked how the competitions are being decided. We are not rolling dice or using random outcome generators. For each match, we (K. Winchell, M. Muñoz, and P. Muralidhar) are reading up on the biology of the species involved and we debate what would happen if they were to meet each other and try to highlight some facts about each. In cases where we might be biased we step aside and let the others decide. If it were up to me of course, Anolis cristatellus would be in the final! (Really, they’re scrappy and mean little guys!)