Category: All Posts Page 30 of 148

Dominance and Anoles: It’s Risky at the Top, But Worth It

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On April 27, 2020

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Two anoles duking it out. Photo from sciencesource.com

Give the elaborate and charistmatic behaviours of our favourite lizards — anoles — many researchers have attempted to piece apart the intricacies of anole social dynamics. In a recent study in Zoology, Glenn Borgmans (University of Antwerp) tests whether dominant adult male American green anoles (A. carolinensis) – dominant in relation to other males – are actually at an advantage, for example by establishing priority access to food or other resources, or if risks associated with being the big boss in town outweigh any perceived benefits, like an increased likelihood of injury due to aggressive male-male interactions. You can read all about it here!

 

Abstract
Male Anolis carolinensis lizards will fight and form social dominance hierarchies when placed in habitats with limited resources. Dominance may procure benefits such as priority access to food, shelter or partners, but may also come with costs, such as a higher risk of injuries due to aggressive interaction, a higher risk of predation or a higher energetic cost, all of which may lead to an increase in stress. While most research looks at dominance by using dyadic interactions, in our study we investigated the effect of dominance in a multiple male group of A. carolinensis lizards. Our results showed that dominant males in a multiple male group had priority access to prey and potential sexual partners but may run a higher risk of predation. We could not confirm that dominant males in a multiple male group had a higher risk of injuries from aggressive interactions or a higher energetic cost by being dominant. Overall our results seem to indicate that dominant male A. carolinensis lizards in a multiple male group obtain clear benefits and that they outweigh the disadvantages.

Dominant lizards ate more food items (left; A) and hid less (right; B) than more submissive individuals.

Borgmans, G., Van den Panhuyzen, S. and Van Damme, R., 2020. The (dis) advantages of dominance in a multiple male group of Anolis carolinensis lizards. Zoology, 139, p.125747.

Salmonella in Japan’s Green Anoles

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On April 25, 2020

In All Posts, Introduced Anoles, New Research

When I hear or read Salmonella, I think of my mom explaining to my 7-year-old self why I shouldn’t eat raw chicken (to be clear, I never expressed interest in doing this, but lesson learned nonetheless). According to the U.S. Centers for Disease Control and Prevention, most instances of Salmonella bacteria making people sick do in fact result from transmission by food. But Salmonella infection can come from other sources, including direct contact with living animals, particularly reptiles (including birds which, in case you haven’t heard, are reptiles). So I was only a little surprised when I came across a recent paper in the Journal of Veterinary Medical Science, based in Japan, documenting the prevalence of Salmonella in the green anole, Anolis carolinensis, on Okinawa Island, Japan.

Of the 706 green anoles from Okinawa Island whose intestinal contents were analyzed for Salmonella presence between 2009 and 2014, only 2.1% tested positive. That number is low compared with published results for green anole populations in Florida (7.5%), Chichi Island in Japan (34.2% – this study was highlighted here on Anole Annals when it came out in 2013), and Guam (76.2%). I’m struck by how much these percentages vary. Green anoles have been in Florida for millions of years, whereas populations in the other locations have only been established for tens of years. The authors hypothesize that infection rate in recently introduced populations should correlate with how long the population has been established. Testing this hypothesis will require data from more populations.  It also appears that we know little about whether anoles are affected by carrying Salmonella, although a quick search did reveal this study involving the brown anole, Anolis sagrei.

All told, we have a lot to learn about anoles and Salmonella. In the meantime, please protect yourself from Salmonella infection by following basic food safety precautions: refrigerate foods adequately, wash fruits and vegetables and cook meat and eggs thoroughly, and clean potentially contaminated cookware and utensils with soap and water. Most importantly, WASH YOUR HANDS, although I assume that like me, you are already doing this approximately a hundred times per day (for those of you reading this in the future, I’m not a weirdo. We’re in the middle of a pandemic).

For those who may be interested, green anoles became established in and around Japan several decades ago and are considered an ecologically disruptive pest. If you want to read more, here are links to some old Anole Annals posts on various topics related to the region’s green anoles: trapping efforts, population age structure, range expansion. Enjoy!

Anolis cristatellus Journal Cover!

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On April 15, 2020

In All Posts, New Research

Hot off the press — the latest anole journal cover! In this issue of Nature Ecology & Evolution, Shane Campbell-Staton and I led a team of researchers to explore the effects of urban heat islands on anoles. We found that not only can urban Anolis cristatellus tolerate higher temperatures than their forest counterparts, but also identified genomic regions associated with divergent thermal tolerance. Check out a summary of this work at the urban evolution blog I co-edit, Life in the City: Anoles Adapt to Beat the Urban Heat.

Anole Online Learning Resources

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On April 13, 2020

In All Posts, Education and Anoles

The days of self-isolation and quarantine are dragging on as COVID-19 continues its worldwide rampage. We may all be a little less productive than we had thought we would be as we tend to unruly kids and rogue parents who won’t stay indoors. Here at Anole Annals, we’ve scoured our past posts and brainstormed some of our favorite learn-at-home resources to help keep you entertained at home while learning about your favorite lizards!  Whether you’re a seasoned researcher looking for a break, a teacher in search of remote learning activities, or a parent at home with kids in need of educational activities, we hope you find the following resources useful.

 

HHMI BioInteractive

HHMI produced several fantastic videos and learning modules perfect for learning about anoles, ecology, and evolution in the classroom and at home! Each of the activities also comes with handy educator materials to make sure your newly homeschooled students gets the most out of these resources.

The Origin of Species: Lizards in an Evolutionary Tree — This short video (~17 minutes) covers the concepts of adaptation, islands as natural laboratories, speciation, and convergent evolution. Pair the video with the associated interactive activities and discussion prompts to get the most out of this resource. Start with this one, since all of the other activities produced by HHMI relate back to the concepts covered here.

Lizard Evolution Virtual Lab — This all inclusive four part learning module involves videos and an interactive web application (also available for IOS) to learn about ecomorphs, phylogenies, experimental data, and dewlaps. Students will collect and analyze data as they learn about the scientific process and anole themed concepts. The modules also have embedded mini quizzes to make sure your student is understanding the information, and educator materials to help you guide your students as they learn.

The Lone Anole — This activity is a short conversation starter based on a photo of the Plymouth anole (Anolis lividus) to use with students to discuss ideas of adaptation and natural selection.

One of the sample cards for students to “collect data” from in the HHMI  selection by predation activity.

Look Who’s Coming for Dinner: Selection by Predation — In this interactive activity, students are walked through the scientific process to learn how to develop a hypothesis, collect data, and analyze results with plotting and basic statistics. This activity is based on the study: Rapid temporal reversal in predator-driven natural selection (Losos et al. 2006). Everything you need to complete the virtual experiment is included!

Effects of Predation on the Niche of Lizards — This short activity guides students through interpreting a scientific figure from the study: Predation on a common Anolis lizard: can the food- web effects of a devastating predator be reversed? (Schoener, Spiller, and Losos, 2002).

How Lizards Find Their Way Home — This short video (8 minutes) is based on the research of Manuel Leal. Watch a real scientist design an experiment to answer a question and carry out fieldwork radio tracking lizards! Produced by Day’s Edge Productions.

Lizards in the Cold — This short activity based on the study Winter storms drive rapid phenotypic, regulatory, and genomic shifts in the green anole lizard (Campbell-Staton et al. 2017) teaches students how to interpret a scientific figure and is a good conversation starter for discussing natural selection and climate change.

Lizards in Hurricanes — Another short activity based on a study by Donihue et al. (2018): Hurricane-induced selection on the morphology of an island lizard. Students are asked to review a figure from the paper and discuss how hurricanes and other extreme weather events can lead to morphological change, and how scientists can experimentally investigate these changes.

Reproductive Isolation and Speciation in Lizards — This short animated video (~2 minutes) discusses the process of speciation and the role of the dewlap in reproductive isolation in anoles.

Using DNA to Explore Lizard Phylogeny — In this interactive activity students learn how to build a phylogeny based on common traits and then by using DNA sequences to explore the concept of convergent evolution. As with the other activities, everything you need to do this experiment at home is provided digitally.

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Ever Wonder if Anoles Eat Scorpions?

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On April 7, 2020

In All Posts

They do! Rodríguez-Cabrera and colleagues report in the latest issue of Euscorpius: Occasional Papers in Scorpiology on predation on scorpions in Cuba. In addition to the A. homolechis and A. sagrei shown above (left and right, respectively), A. equestris was also observed eating a scorpion.

Help Needed Identifying an Ecuadorian Anole

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On April 4, 2020

In All Posts, Ask the Experts


Recently, a friend found the anole pictured above in Mompiche, Ecuador. As of now, the identity of this anole remains unknown.

The closest matches I could find were Anolis bombiceps and A. lyra, but there were problems with both of those species. Anolis bombiceps lacks a spot on the dewlap, and is not known to occur as far west as Mompiche. On the other hand, Anolis lyra seemingly has either a red or white dewlap without any blue coloration. This individual seems to match up perfectly with A. lyra in all other regards.

This may simply be an individual displaying unusual dewlap coloration, but I’m interested in hearing your thoughts (Editor’s note: AA‘s comment function is broken, so please use the form below).

Thanks in advance!

EDITOR’S UPDATE: SEVERAL READERS WROTE BELLA TO SAY THAT THIS IS A FEMALE A. LYRA. NOTE THE DIFFERENCE IN COLOR OF THE DEWLAP IN BELLA’S PHOTOS AND THE ONES IN A PREVIOUS POST ON ANOLE DEWLAP SEXUAL DICHROMATISM.

 

Donations of Shed Anole Skins Needed

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On April 1, 2020

In All Posts

Anolis aquaticus

Recently, my lab has been excited to begin work on some of the morphological, behavioral, and physiological aspects of so-called “underwater breathing” in semi-aquatic anoles. Given the current circumstances, I need to ask for a little help from the anolologist community. My collaborators and I are studying the microstructure of semi-aquatic anole skin – what about the skin allows a bubble to stick and move around the way it does?

We are seeking shed anole skin samples to compare with Anolis aquaticus. Any anole species or sex or any size sample will do. Really, a bit of shed skin that is even 1 cm long from a single individual would be a “big” sample and enormously helpful!

If anyone out there keeps anoles of any species in lab or at home and would be willing to drop a fragment of shed skin into an envelope for me, it would go a long way to helping us keep this project moving despite the moratorium on fieldwork.

If you are able to help, you can message me below. Thank you all in advance!

 

Anoles on TV: Harry the Lizard in Death in Paradise

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On March 8, 2020

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Harry the lizard

I could have sworn we had a post on this some years ago, but can find no record of it in the Annals. So, just to get up to speed, Death in Paradise is a British detective show set on the island of Guadeloupe (Update, April 2021: the island is Saint Marie, a fictitious island in the vicinity of Guadeloupe and Martinique). A recurring character is Harry, who looks more-or-less like an anole. The show is set in Guadeloupe, hence the reasonable supposition that he is an A. marmoratus, as some articles explicitly state.

Speaking of articles, this post is prompted by a number of recent press articles highlighting Harry, including this piece in The Sun and another in the Daily Express. And one more from earlier this year. You may not be surprised to learn that Harry is not played by a real saurian actor, but rather is the result of CGI. The Sun‘s piece provides more detail, including the embedded video.

More favorite details on our favorite TV character can be found on his Wiki Fandom page.

Living High with a Cool-Cold Anole – Part I

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On March 6, 2020

In All Posts

On march 19, 2013, Jonathan Losos wrote about Anolis heterodermus in this blog, on a post called “Adventures with Phenacosaurus”: “…I have to comment on the little-studied thermal biology of this species. The weather when we were there was usually overcast with the sun occasionally bursting out. Temperatures were usually in the 16-20̊ range. And the lizards were active! Moreover, we were at only about 2600 meters, but I have heard reports of them being found as high as 4000 meters! Clearly, a study on the thermal biology of this species would be fascinating!” One year later, I began to investigate this topic on A. heterodermus.

All my life I’ve loved reptiles, but only recently as part of my undergraduate studies in biology in the National University of Colombia, have I started in the herpetological world with Drs. Adriana Jerez and Martha Calderón. I was particularly intrigued by the thermal biology of these organisms. Soon I discovered that I’ve always lived in a high-elevation, cold city, Bogotá, in a neotropical country, Colombia, making the reptile species around me, which are ironically unknown, perfect models for questions about thermoregulation in reptiles.

A female Anolis heterodermus

As I tried to decide which of these species would be my model for my undergraduate thesis, I realized that my professors and some of my colleagues had already started to study some of the high-elevation species, like the high-Andean snake Atractus crassicaudatus, the microteiid Anadia bogotensis, and the collared tropidurids Stenocercus trachycephalus and S. lache. I realize now that my choice of the high-Andean lizard Anolis heterodermus for my study was one of the best decisions of my life as a biologist.

Between 2014 and 2015, I carried out my undergraduate thesis research under the direction of Dr. Martha Calderón on thermoregulation of Anolis heterodermus in Tabio, a town at 2650 m asl, close to Bogotá, Colombia. During my research, Martha, my colleagues and I had the opportunity to know Dr. Barry Sinervo and his group, who helped us with equipment and suggestions for our projects. Finally, in 2017, after my thesis was approved and I obtained my biology university degree, Martha and I published my first article.

Measuring an individual of Anolis heterodermus with calipers

Anolis heterodermus lives in a cold, low-quality thermal habitat that gets worse in wet seasons. Surprisingly, during the wet season, Anolis heterodermus copes succesfully with this seasonal variation and adjusts behaviorally to thermoregulate more actively to compensate for the reduction in the thermal quality of the habitat. In this way, these lizards match achieve their preferred temperatures just as in dry season. This match also occurs mostly at midday, particularly in sunny perch sites, confirmed by operative temperature data, which suggests that A. heterodermus is a heliothermic species. Additionally, sexes and ages are not different in their thermal traits, such as body and preference temperatures.

Study site: Tygüa Magüe Ecopark, Tabio, Colombia, at 2650 m asl.

But the most incredible trait of this species is its capacity to take advantage of the few sunny hours and sunny microhabitats to thermoregulate, taking into account that the tropical high-elevation ecosystems like the high-andean shrubs and forest, and subparamo and paramo not always are cold environments, but have large thermal fluctuation during the day too, which is reflected in the wide range of body (16.6-31.9°C) and preferred (19.1-30.2°C) temperatures. Definitely Anolis heterodermus is a very plastic thermoregulating species, as it has to be, because it is the anole species found at the highest altitude known.

 

Cite: Méndez-Galeano, M. A., & Calderón-Espinosa, M. L. (2017). Thermoregulation in the Andean lizard Anolis heterodermus (Squamata: Dactyloidae) at high elevation in the Eastern Cordillera of Colombia. Iheringia. Série Zoologia, 107.

Photos: Andres Herrera

 

Field Assistant Needed for Anolis Research in Florida!

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On March 4, 2020

In All Posts

Anolis sagrei

Anolis sagrei in Miami, Florida (K.Winchell)

 

UPDATE: POSITIONS FILLED! SORRY!

 

We are looking for a field assistant to help us conduct behavioural research on Anolis sagrei on small dredge-spoil islands near Ft. Pierce, FL, from April 22 to May 21. Daily activities include searching for and observing marked lizards as well as collecting habitat data. We will work long hours on most days (beginning 7-8am). Applicants should be prepared for hot and humid work conditions as well as travel on a small boat. Applicants must be comfortable handling lizards and using binoculars and should be adaptable to changing plans. All expenses (airfare, food, lodging) will be covered and a stipend will be provided.

If interested, please contact Ambika Kamath: ambikamath@gmail.com and Nick Herrmann: nicholas.carl.herrmann@gmail.com with a
brief letter describing why you are interested in this position and any relevant research experience along with your CV and the names and contact information of a professional reference whom we may contact by email. We will review applications as they arrive until the position is filled.

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