Anole Annals

Chelsea Connor presenting her research at SICB 2020

Invasive species can often compete for resources with native species, which can have a negative impact on the community. This is an especially common occurrence when it comes to the diet of these competing species. It is important to investigate the diet of both the invader and the native species in order to determine whether this competition is present and if it will cause negative effects in the future.

Chelsea Connor grew up on the island of Dominica. She is currently an undergraduate student at Midwestern State University in Wichita Falls, Texas in the lab of Dr. Charles M. Watson. Her research addresses the dietary niche overlap of native and invasive species on her home island of Dominica. For this research, Chelsea and another undergraduate student, Destiny Zinn captured and collected feces from Anolis oculatus (a native species) and Anolis cristatellus (an invasive species) on Dominica. They successfully extracted and amplified a region of the cytochrome oxidase I gene from 44 samples. Then they ligated the PCR products and transformed them into E. coli to grow on a plate. After this, they sequenced the resulting clones and placed them into Molecular Taxonomic Operational Units, which were matched using the databases BOLD and GenBank with the help of Daniella Biffi and Dr. Dean Williams at Texas Christian University. They calculated the similarity of diets using the Sørenson coefficient.

Chelsea and her collaborators found a shockingly low degree of dietary overlap, discovering that these two species of anoles on Dominica consume different arthropod prey. They identified 40 prey species in this experiment, and only 4 species were contained in the diet of both the native and invasive anoles. Chelsea emphasizes that there may be dietary niche partitioning, which could explain how the two species are able to coexist across the island and avoid competition.

SICB 2020: Green Anoles Have Higher Heat Hardening Capacity Than Brown Anoles

By Chris Thawley

On January 6, 2020

In New Research

Ectotherms rely on interactions with surrounding thermal environments to regulate their body temperature. If their body temperatures get too low or too high, ectotherms may be unable to move effectively or escape dangerous temperatures, potentially leading to death. One plastic physiological response which may help ectotherms avoid the effects of dangerously high body temperatures is heat hardening. Heat hardening is a type of physiological flexibility that entails an organism increasing its heat tolerance after a previous exposure to high temperatures. In areas with high temperatures, differences between ectotherms in their abilities to effectively conduct heat hardening could affect competition between them.

A green anole (Anolis carolinensis) basks at an elevated perch.

Sean Deery, a masters student in the Gunderson lab at Tulane University, chose to investigate heat hardening capacity in two species of anoles, the native green anole (Anolis carolinensis) and the invasive brown anole (Anolis sagrei), both of which are present in New Orleans. As brown anoles have expanded throughout the area, they have displaced green anoles, forcing them higher into vegetation, a pattern repeated in other areas of the southeastern U.S.

Brown anoles are particularly adept at exploiting urban habitats, where temperatures may be considerably higher than surrounding natural areas due to the urban heat island effect. Sean wondered whether the competitive advantage of brown anoles over green anoles might be based in part on a superior heat hardening capacity, which could support their dominance in urban areas.

(a) A male green anole and (b) and a displaying male brown anole in Florida.

To quantify heat hardening in this system, Sean captured green and brown anoles and first measured their upper critical thermal maximum (CTMax) by steadily ramping up their body temperatures until the lizards lost coordination. CTMax represents a temperature that could prove lethal to a lizard as it would be unable to escape these hot conditions. After allowing lizards to recover, Sean measured their CTMax again after periods of 2, 4, and 24 hours. Heat hardening was calculated as the difference between the initial CTMax and the subsequent measurement after exposure to those initial high temperatures.

Sean’s results were surprising: He found that brown anoles showed no evidence of heat hardening at any time after an initial measurement of CTMax. In fact, brown anoles showed a reduction in CTMax, suggesting that the initial testing may have stressed them and reduced their ability to cope physiologically with higher temperatures. Green anoles on the other hand showed a moderate heat hardening response, with significant increases in CTMax just 2 hours after exposure to high temperatures. Sean’s results also suggest that individual lizards with lower initial CTMax values showed greater heat hardening.

For now, it appears that heat hardening is not a factor driving invasions of brown anoles in the southeastern U.S., but the differences between these two species are intriguing. Sean hopes to expand on this work by investigating molecular mechanisms that may support or inhibit heat hardening, such as expression of heat shock proteins.

2019 in Review

By Kristin Winchell

On December 31, 2019

In All Posts

Anolis chloris on the cover of Evolution, photo by J. Salazar

As 2019 wraps up, I thought I would take a moment to reflect on some of the major happenings of the year. It was an active year for Anole Annals and for the anole community. In 2019 we saw ~100 papers on anoles published (note: this is probably an underestimate, since this was based on my google scholar search for “Anolis” and “anole”; check out my list here). As you can see from the word cloud at top of the titles of these papers, anolologists are hard at work studying the ecology and evolution of our favorite lizards. Some major themes from the past year:

Thermal Biology

Thermal biology has long been a topic of interest to anolologists, and 2019 was no exception. Several papers dug into the thermal physiology of anoles this year, pushing the field into new directions. Muñoz and Bodensteiner examined how behavior and environment interact to shape thermal physiology of Dominican anoles. Also working with the Muñoz lab, Salazar et al. compared thermal physiology of mainland versus island anoles to find that island lizards maintain higher body temperatures; their paper was featured on the cover of the journal Evolution. Several groups of researchers set out to understand how elevated temperatures of cities affect anoles. Hall and Warner tested the thermal sensitivity of lizards during development with experiments on Anolis sagrei and Anolis cristatellus, and Battles and Kolbe looked at these same two species in urban Miami, finding that thermal ecology might explain patterns of habitat use in the city.

Performance & Novel Insight into Traits

Likewise, performance has long been a focal theme in anole biology, but 2019 saw researchers investigate traits and their interaction with environments in new ways. Husak and Lailvaux answered the burning question of whether exercise really has any benefits —at least in anoles — and found that lazy lizards are more likely to survive in the wild. Lailvaux and team also looked at inter- and intra-individual variation in bite force, sprint speed, and endurance, finding sex-specific trade-offs between bite-force and sprint speed. Dufour, Donihue, and Losos followed up on their previous hurricane work with a new study showing an increase in clinging performance of anoles on Dominica following Hurricane Maria. Battles, Irschick, and Kolbe took a close look at locomotor performance and limb kinematics of lizards running on tracks that varied in inclination and smoothness, finding that lizards run slower on vertical and smooth tracks and that urban and forest lizards approach moving on these surfaces similarly. Smith et al. analyzed the expression of genes underlying muscle movement to find that gene expression differs between jaw and leg muscles, giving insight into the molecular basis of performance differences. And Ríos-Orjuela et al. made progress on understanding muscle and skeletal structure of limbs and their relation to performance for two species of continental anoles.

2019 was also a year in which researchers took the time to understand some less–well-studied traits. Baeckens et al. took a really close look at scales and described ontogenetic patterns in scales of Anolis cristatellus using a novel approach: gel-based stereo-profilometry. Wegener et al. found that head size of both male and female A. sagrei increase at higher population densities, as do injury rates. Yuan and colleagues sunk their claws in deep to understand the co-evolution of claws and toe pads across 57 species of anoles. Lastly, Prado-Irwin, Revell, and Winchell looked at a poorly understood trait – the tail crest – in A. cristatellus and found that lizards had larger tail crests in hotter and drier regions across the island of Puerto Rico, including in urban habitats.

Prado-Irwin et al. measured tail-crests in urban and forest A. cristatellus

Urbanization

Finally, continuing with the a trend that has been building over the past few years, several researchers published studies on the ecological and evolutionary effects of urbanization on anoles. Some of these I mentioned above, but here’s some additional studies on urban anoles. Avilés-Rodriguez and Kolbe found that A. cristatellus alter their escape responses in cities in part because of habituation but also because of locomotor constraints of using anthropogenic structures. Winchell, Briggs, and Revell analyzed patterns of injuries and asymmetry in urban versus forest populations of A. cristatellus in Puerto Rico. Several researchers took advantage of the abundant and urbanophilic anoles of Florida. Chejanovski and Kolbe evaluated the combined influences of predator abundance, conspecific density, and abiotic environment on body size of urban A. sagrei. Stroud et al. analyzed behavior of A. sagrei in the Miami metropolitan area, finding a two-fold increase in dewlap displays in the more open urban habitats. Thawley and colleagues looked at the interaction between morphology, thermal preference, and parasitism in Miami anoles, with differences in parasitic infection in A. sagrei but not A. cristatellus between urban and rural populations. Lastly, Tiatragul and the Warner lab described variation in nest site locations in urban habitats.

Anolis aquaticus has a bright orange dewlap (photo by Peter Mudde)

Other Significant Events of 2019

The past year has seen several other wonderful papers not highlighted here, if I missed one of your favorites, let me know in the comments. There were also many significant events in the Anole community in 2019 not captured by the publication record. Here’s a couple of my personal favorite stories from 2019. We’ve all wondered and hypothesized if the color shirt we wear while catching anoles influences our capture rate. Well Fondren, Swierk, and Putman finally answered the question for us. Turns out researchers were able to capture more A. aquaticus when they were wearing orange clothing, the same color as the dewlap! Another significant finding in A. aquaticus was the news that the lizard can breathe underwater, apparently using an air bubble on the snout. Although this news broke to the anole world in 2018 (check out the Anole Annals post to see some amazing video!), it was a major story in 2019 across regular news outlets and was published as a Natural History Note by Lindsey Swierk in the March publication of Herpetological Review.

Here on Anole Annals, we had some major happenings too! In January we published the 7th edition of the Anolis Newsletter, thanks to contributions from all of you and the hard work of the newsletter editors James Stroud, Anthony Geneva, and Jonathan Losos. We also unveiled the revamped Anole Annals website, which we are working hard on making a repository of information on anoles – from videos to species information and more. Stay tuned in the coming year as we unveil more updates and implement a new editorial board to bring Anole Annals into the new decade!

Lizards in the Classroom: Learning about Evolution in Action

By Inbar Maayan

On December 27, 2019

In All Posts, Education and Anoles

We are all familiar with the great insights that lizards offer researchers working on evolution– and they’re also great teaching tools! Timna Brown and Jessie Dorman, two fantastic science teachers at New Albany High School in Ohio, developed a lizard-based activity to teach their students about the different mechanisms driving evolution. Brown has posted about this activity on Instagram, and I was lucky enough to get the details from her:

“Getting students excited to learn about complex scientific concepts is not always easy, but this evolution activity is robust, challenging, and brings the concepts of evolution to a level which students can understand and apply. We call it ‘Don’t be a Lazy Lizard!’

Students use straws, scoops and spoons to “feed” at different types of resource stations.

With the goal of helping students understand the complexities and misconceptions surrounding evolution, this simulation teaches students about a multitude of concepts. Focusing on the mechanisms of evolution, these topics include: natural selection, drift, inheritance, mutation effects on a population, predator-prey relationships, environmental pressures, ecological niches, speciation, meiosis, hybridization, reproductive and geographic isolation, genotype, phenotype, dominant, recessive, biomagnification, importance of energy to reproduction, and energy’s role in evolution. Each of these real-world factors are introduced to the students in a tangible way: for instance, a trait might be adaptive in one environment, but costly in another.

In this simulation, students act as lizards with different traits such as body coloration (brown and green) and mouth type (straw, spoon, scoopy) which play an integral part in their ecology, behavior, and interactions. Through dozens of generations, the students compete with one another for access to nectar (water) at a variety of feeding sources (trees, reservoirs, lakes, and troughs). As they try to survive and thrive in their environment, they ‘reproduce’ with one another and exchange genetic information, demonstrating the roles of genotypes, phenotypes, dominant traits, and recessive traits. As lizards in the simulation, they deal with changing food supplies, introduction of predators and food sources, and interspecific competition. With each passing generation, the phenotypic and genotypic frequencies change, and students are able to see populations change over time: EVOLUTION! Things can get pretty heated when these lizards compete, so don’t be a lazy lizard!

Once they were done with the simulation, students graphed their data to understand how populations change over time.

Following the activity, students work on applying the knowledge they gained by answering questions from real-life scenarios of evolution in nature. Taking the data from the simulation, students graph the changes of different phenotypes over time, and connect these changes to various selective pressures. They also work on Hardy-Weinberg problems to investigate how scientists track changes in genotype frequencies related to various traits. Students also develop storyboards to show how their understanding of evolution changed over time as they participated in a population subject to various selective pressures. This activity takes a week or so, but it’s very worthwhile and has been shown to help students understand the critical concepts of evolution.”

Timna Brown and Jessie Dorman, evolution educators extraordinaire.

Activity Adapted from Lazy Lizards, by Jessica Dorman. For the activity guide, contact Jessie Dorman (dorman.1@napls.us) or Timna Brown (brown.76@napls.us).

Help Identify Anoles of Cuba

By Vladimir Dinets

On December 22, 2019

In All Posts

1. Hills above Moa

I just spent a week in Cuba, mostly in the far east, and found a few interesting anoles. Help with identification will be appreciated. Here’s the first batch (all from Moa-Baracoa area in the east).

2. Hills above Moa

3. Hills above Moa

4. Hills above Moa

5. Alturas de Baracoa

6. Alturas de Baracoa

7. Baracoa area

8. Coast west of Baracoa

9. Hills above Moa

9. Hills above Moa

10. Hills above Mo

11. Hills above Moa

Are you going to SICB in 2020? Blog for us!

By Anthony Gilbert

On December 20, 2019

In All Posts

The end of 2019 is nigh, and soon people will be traveling home to spend time with loved ones, eating a superfluous amount of cookies and sweets, and of course, working on that poster or talk for the 2020 Society for Integrative and Comparative Biology (SICB) meeting in Austin, Texas. SICB is one of the largest national conferences for biologists, where an incredible diversity of research is presented each year. And of course, SICB meetings are home to several Anolis presentations, with approximately 45 or more talks and posters this year featuring anoles.

Every year at SICB, Anole Annals tries to cover as many of the anole talks and posters as we can, and this year is no exception! AA relies on conference attendees to blog about all of the awesome anole work being presented, with a strong focus on undergraduate and graduate research. If you’re a student or student researcher attending SICB, blogging for AA is a fantastic way of getting experience in communicating science with a broader audience. In addition, if you are presenting work on anoles at SICB this January and want to help us blog, we’ll return the favor and cover your work for the blog! Anybody can join the AA family- undergraduates, graduate students, postdocs, and faculty. If you’re interested in blogging for AA at SICB this year, please shoot me an email at anthony.gilbert09@gmail.com or leave a comment on this post and we can get you going. We can provide assistance, examples, and answer any questions you may have when it comes to blogging for AA. Thanks all!

Test Your Anole Identification Moxie!

By Wolfgang Dahm

On December 9, 2019

In All Posts

I am an enthusiastic hobby photographer. On walks or on vacation I always try to find animals and of course I am happy about every new species.
Among others I have found some Anolis in the last months. I’m not sure about the species or subspecies. That’s why I want to ask the experts for help.
I look forward to your answers. Many thanks in advance and greetings from Cologne, Germany.
Wolfgang

No 1, La Romana, Dom. Republik

No 2, La Romana, Dom. Republik, possibly Anolis distichus properus?

No 3, Saint Croix, US Virgin Islands, possibly Anolis acutus?

No 4, Saint Croix, US Virgin Islands, possibly Anolis acutus?

No 5, El Yunque National Forest, Puerto Rico, possibly Anolis evermanni?

No 6, El Yunque National Forest, Puerto Rico

No 7, El Yunque National Forest, Puerto Rico, possibly Anolis evermanni?

No 8, El Yunque National Forest, Puerto Rico, possibly Anolis cristatellus ?

No 9, El Yunque National Forest, Puerto Rico, possibly Anolis cristatellus ?

No 10, El Yunque National Forest, Puerto Rico

No 11, El Yunque National Forest, Puerto Rico, possibly Anolis krugi ?

No 12, El Yunque National Forest, Puerto Rico

No 13, El Yunque National Forest, Puerto Rico

No 14, El Yunque National Forest, Puerto Rico, possibly Anolis stratulus ?

No 15, Corcovado National park, Costa Rica

No 16, Corcovado National park, Costa Rica

No 17, Corcovado National park, Costa Rica

No 18, Dominica, not far from Roseau, possibly Anolis cristatellus ?

No 19, Grenada, possibly Anolis richardii ?

No 19, Martinique, Chancel, Island, possibly Anolis roquet summus?

Anole Annals 2020 Calendars Now Available!

By Kristin Winchell

On December 6, 2019

In All Posts

1st place: Anolis sagrei by Laurel Robertson

Thank you once again to everyone who participated in this year’s Anole Annals photo contest! As usual, we received tons of great photos, and we’re ready to announce the results. First up, the grand prize winner, is the above photo of Anolis sagrei from Port Saint Lucie, FL taken by Laurel Robertson. The second place winner is below, Anolis chloris from Parque Nacional Natural Tatamá, Colombia, by Jhan Salazar. Congratulations!

2nd place: Anolis chloris by Jhan Salazar

The rest of the winners are below, and their photos can be seen in the 2020 calendar here! Click the link to order your calendar. Do it now to take advantage of the Cyber Week sale – 50% off ending today!

Congrats again to all the winners, and happy holidays!

Anolis aquaticus
Lindsey Swierk

Anolis mariarum
Camilo Botero

Anolis carolinensis
Laurel Robertson

Anolis latifrons
Jhan Salazar

Anolis pulchellus
Alberto Lopez

Anolis sabanus
Norman Zedler

Anolis grahami
Kristin Winchell

Anolis chloris
Jhan Salazar

Anolis agassizi
Juan Daniel Vásquez-Restrepo

Anolis carolinensis
Joaquin Monteverde

Anolis fowleri
George Sandler

Anolis sagrei
Laurel Robertson

Photo Contest 2019 – Time to Vote!

By Kristin Winchell

On November 22, 2019

In All Posts, Anole Photographs

The Finalists Are In!

Thanks to all who submitted photos for the Anole Annals calendar contest–we received lots of great submissions! We’ve narrowed it down to the top 27, and now it’s time for you to vote! Here’s a slideshow of the finalists:

This slideshow requires JavaScript.

Vote Now!

Choose your 6 favorites in the poll below. You can click on the thumbnail to view full-size images in the poll, check the box next to your picks. You have 10 days to vote – poll closes next Sunday at 11:59pm (12/1). Spread the word!

Help Identify Costa Rican Anole

By Jonathan Losos

On November 22, 2019

In All Posts

Reader Roger Birkhead has asked for help ID’ing this Costa Rican anole on iNaturalist. Can anyone help?