Professor of Biology and Director of the Living Earth Collaborative at Washington University in Saint Louis. I've spent my entire professional career studying anoles and have discovered that the more I learn about anoles, the more I realize I don't know.
Six-toed brown anole reported by DeVos et al. 2020 in Herp. Review
Read all about them in the most recent (December 2020) Natural History Notes section of Herpetological Review (searching on “Anolis” will get you to these reports expeditiously in the pdf).
From Mendyk et al., Herp. Review, 2020
Anolis bartschi. Photo by Shea Lambert
Anolis bartschi is one of the many spectacular anoles of Cuba. Hailing from a restricted area in western Cuba, little is known about this species (though see a previous Anole Annals dispatch).
A new paper just out in Phyllomedusa provides new diet data. Here’s some details:
Trophic ecology and morphology of Anolis bartschi (Squamata: Dactyloidae) in Viñales National Park, Cuba
L. Yusnaviel García-Padrón, Geydis León Amador, Mariela Mezquía Delgado, and Yusvel Martínez Serrano
Abstract
Trophic ecology and morphology of Anolis bartschi (Squamata: Dactyloidae) in Parque Nacional Viñales, Cuba. Little is known about the trophic ecology of most anoles of Cuba. Morphology is directly related to ecological functions in lizards, such as feeding strategies, interspecific competition or energetic demands linked to reproduction. Anolis bartschi is a regionally endemic species, restricted to karstic hills of western Cuba. Here, we offer new insights into the trophic ecology of this species, and its relation to head morphology. We captured 131 adults; males were larger than females in size and head width. Most of them had prey in their stomachs. Males consumed more prey than females, but the latter consumed larger prey. Prey overlap within sexes was detected in the dry season, but trophic segregation occurred in the rainy season. Hymenoptera was the most frequently consumed prey in both sexes. In addition, females ate Blattodea and Coleoptera, and males consumed more Diptera. We suggest that this lizard prefers sedentary rather than mobile prey. According to our dataset and field observations, A. bartschi is a bimodal forager lizard, but research on temporal (daily and annual) variation in diet is recommended for a proper forage classification of this lizard.
Anolis roquet. Photo by Gaëll.
Read all about it in the latest issue of IRCF Reptiles & Amphibians.
Flicker is the bimonthly publication of the Cayman Islands Department of the Environment. The October issue, available here, reports on the introduction of the green anole, Anolis carolinensis, to Grand Cayman, and on continuing efforts to remove green iguanas from that same island. Older issues are also available. If you’d like to receive future issues, contact the editor.
Photo by Rachel Easton.
Periodically, we here at Anole Annals get reports of mating between green and brown anoles. Usually, it turns out to be a case of misidentification–often the “brown” anole is really a green anole in brown color phase, but sometimes it actually does happen. The most recent report comes from reader Rachel Easton, who tells the story of the picture above: “I’ve had them for a few weeks but they lived together at the pet store for months before I had them. They are in a 20 gallon in my greenhouse. This is the first time I’ve witnessed the mating behavior. I moved their tank to another location and about 3 minutes later they were mating. I occasionally see them displaying their throats at one another but I assumed it was a territorial dispute over the best basking spot.”
Matt R. Whiles, Chair and Professor in the Soil and Water Sciences Department at the University of Florida provides these details:
Specimen was not captured, just photographed by my wife Lindsay Hsieh, who is familiar with Anolis and recognized that it was different looking. Observed in Alachua county FL, west of Gainesville in a horse barn facility – coordinates: 29O 41’08”N 82O 30’18”W; date was November 10 2020. A. carolinensis are common on the barn, but none we’ve seen look like this. The owners of the facility routinely haul horses back and forth from Gainesville to south Florida, so could be a transplant.”
He then asks: “I’ve seen thousands of A. carolinensis, and never one like this. Do you think this is just a color/pattern display, or would this individual always look like this? We are keeping an eye out for it again and will try to collect it if you want the specimen.”
Thoughts, anyone (including interest in the specimen should it be seen again)? My guess is that these are not permanent markings; the block spot on the head and the hint of an erected nuchal (neck) crest suggests a stress response; perhaps the lizard had just been fighting. Indeed, Dr. Whiles clarified in a subsequent email: “I’ve certainly seen the black spot form on stressed individuals, but never the full patterning. To add to your hypothesis, my wife indicated it was interacting with another Anolis when she saw it (you can actually see the tail of the other individual in the pic).”
In the lizard world, flashy colors attract the interest of females looking for mates. But they can make colorful males desirable to other eyes, too — as lunch.
Assistant Research Professor of Biological Sciences Lindsey Swierk is the first author of an article in the journal Evolutionary Ecology on the topic. Called “Intrasexual variability of a conspicuous social signal influences attach rate of lizard models in an experimental test,” the article details an experiment involving clay models of water anoles (Anolis aquaticus), a species of lizard only found in Costa Rica and a small slice of Panama. The researchers conducted the experiment at the Las Cruces Biological Station in Costa Rica, which is one of the Organization for Tropical Studies’ field stations.
To attract females’ notice, male anoles have dewlaps: colorful extendable flaps of skin under their chins. In most species of anole, dewlaps evolved to be as noticeable as possible within the environment, given an environment’s predominant colors and lighting conditions.
“Even so, we see a lot of variation within a species in just how bright dewlaps are,” Swierk said.
While some water anoles have dramatic red-orange flaps, others have more muted colors, more of a dull brownish-red. Researchers wanted to determine the effect these color variations had on their risk of predation.
While it’s widely assumed that flashier males will attract more attention from predators, few studies actually test this assumption. Logistics may be a factor: Researchers have to separate the effects of sexual colors from other aspects of a creature’s body and behavior, a difficult task when using real animals. As a result, many studies show correlation but not causation.
To prove that flashier males face greater risks of being attacked, the researchers created clay models with colored dewlaps — some bright, some more muted. Many visual predators use a stereotyped “search image” to identify prey, so the models only had to approximate anoles’ general size, color and shape. The dewlap color, however, required special attention.
“Because different animals have different visual sensitivities than we do as humans, getting the colors right was an important consideration in our model design,” Swierk explained. “We ran some pilot trials before this experiment to make sure our models were convincing as ‘lizards’ — and they certainly seemed to be, as many birds and other lizards took bites out of them!”
Researchers were able to identity predators from bite marks in the clay models. They included many species of bird, including the strikingly beautiful motmot with its serrated beak. Basilisks and whiptail lizards were also among the likely attackers. The results proved that flashier lizards really do end up as lunch more often.
If bright colors have deadly consequences, why do female anoles prefer them? One answer is that brighter males have either high-quality genetic material or resources that allow them to handle the risk of getting eaten, Swierk explained.
“Because every individual’s evolutionary ‘mission’ in life is to pass on as many copies of its genes as it can, conspicuous traits like these can evolve if they give an individual a high level of reproductive success — even if the flashy trait ends up killing them in the end,” Swierk said.
Back in 2013, AA featured a number of posts discussing whether and how often bats eat anoles. The discussion ended with a report of a paper documenting extensive anole hunting by the big-eared bat in Panama (see photo above). That paper described how the bats captured their prey: “M. microtis hunts on the wing, checking leaf by leaf in the forest while hovering up and down the understory vegetation.”
Now, a new study has used DNA metabarcoding of fecal samples from the frog-eating bat, Trachops cirrhosus, and has discovered that the bat needs a new common name: the frog-and-lizard-eating bat. That’s right: although DNA from a variety of frog genera was found in the bat poop, the second most common taxon (inhabiting 22% of the turds) after Pristimantis frogs was anoles!
The study did some other clever things as well in an attempt to figure out how the bats found their prey. Here’s what they say in the discussion:
“We found DNA from Anolis lizards in almost a quarter of our bat samples, but bats showed a fairly low response to the rustling sounds of anoles moving through leaf-litter. A previous anecdotal report from Honduras described finding a dead anole in the mistnet pocket with a female T. cirrhosus (Valdez and LaVal 1971). Anoles do make alarm sounds, but do not call, therefore we anticipate that the rustling sounds made by anoles moving through leaf-litter is the most obvious cue they present to T. cirrhosus. We had hypothesized that we would find greater responses to anole rustling sounds in dry season conditions (lizards moving through dry leaves) than wet because movement through dry leaves produces louder, more conspicuous rustling sounds. While we did find anoles in the diet of more T. cirrhosus in the dry season than in the wet season, and we did find higher response to the sounds of anoles moving through dry versus wet leaf litter, these differences were not significant. Why bats did not show more response in general to anole rustles is unclear. One possibility is that since the speaker was in a fixed location, the rustling sound does not move in space as a real moving animal would. Additionally, rustles are relatively low amplitude compared to the mating calls we presented to the bats, which could account for the lower responses. Also, anoles are diurnal, therefore we might not predict them to be moving around at night, and rustling sounds could be indicative of many different potential prey, some more palatable than others. Bats may thus be locating anole prey by some other mechanism than rustling sounds, and one bat did attack a silent, motionless plastic anole model, indicating that T. cirrhosus may be able to locate sleeping lizards using echolocation alone. Anoles are diurnal, so unless one was scared off of its perch, they are unlikely to be moving through the leaf litter at night.”
And just because it’s so cool, I have to add the beginning of the next paragraph:
“Diet samples indicated some predation events that appear to be rare, including predation on the hummingbird F. mellivora, and on the bats Glossophaga soricina, C. perspicillata, and Micronycteris microtis.“
Festive anole in the Gardens by the Bay in Singapore
We’ve reported previously on the introduction of festive anoles (a.k.a., brown anoles) to Singapore. Now, a new report reveals that they are, indeed, spreading far and wide in the island state. How long before they make it to Malaysia (if not already)?
From Hongxia and Zhiyuan. 2020
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