The picture and caption say it all. Read the paper by Felipe Espinoza De Janon and Mario Yánez-Muñoz.
Category: All Posts Page 6 of 146
Some cool canopy-dwelling anoles.
So little is known about what anoles do high above the ground that information from tree climbing censuses is always welcome. Thomas et al. report on their observations of several anoles tens of meters off the ground in the Chocó region of northwestern Ecuador.
The familiar name “Dactyloidae” is no more, as “Anolidae” is the taxonomically appropriate nomenclature for the family under the Zoological Code. As a result, all anoles, such as the A. porcatus above, are now part of the family Anolidae.
In a recent paper in Herpetological Review, Kevin de Queiroz clarifies the family nomenclature of the clade containing Anolis lizards.
Kevin has kindly provided the following abstract to Anole Annals for his article below:
Under rank-based nomenclature, Anolis is currently assigned to the family Dactyloidae under the premise that Dactyloidae is the oldest name in the family group based on the name of a genus included in that taxon (even if that genus is not recognized by subsequent authors who recognize the family). The name Dactyloidae Fitzinger 1843 has been considered to have priority over Anolidae, which has been attributed to Cope (1864). However, Cope (1864) is not the original author of the name Anolidae, which was proposed some 28 years earlier by Cocteau (1836) in a publication that has been overlooked by recent authors. Anolidae Cocteau 1836 has priority over Dactyloidae Fitzinger 1843, and therefore Anolidae is the valid (correct) name of the family that contains the genus Anolis. The publication by Cocteau (1836) also establishes that Cocteau, and not Duméril and Bibron (1837), is the author of the species name Anolis loysiana (originally proposed as Acantholis loysiana).
New literature alert!
The Correct Name for the Taxon Ranked as a Family Containing the Genus Anolis under Rank-based Nomenclature and the Author of the Name Anolis loysiana
Check out the full article in Herpetological Review
de Queiroz (2022)
mCT reconstruction of the second specimen (USNM 5095) of Anolis incredulus (from de Queiroz et al. 2023).
Anolis incredulus, a poorly known Cuban species from the angusticeps species group, is lonely no more. In a recent paper, de Queiroz et al. (2023) report the discovery of an additional specimen of A. incredulus collected more than 100 years prior to the collection of the holotype. The additional specimen (USNM 5095) was tucked away in the Smithsonian’s collection and wasn’t discovered until co-author Esther Langan noticed that specimens in a series labeled as A. guazuma actually appeared to comprise two separate taxa. Upon investigation, one specimen in particular–USNM 5095–was concluded to likely represent the second specimen of A. incredulus. In their paper, de Queiroz et al. redescribe the morphology of this species, infer its phylogenetic position using morphological characters, and note the paucity of ecological data for this anole. Give it a read, it’s open access in Zootaxa!
New literature alert!
No longer in doubt: Discovery of a second specimen corroborates the validity of Anolis incredulus Garrido and Moreno 1998 (Reptilia, Iguania)
In Zootaxa
de Queiroz, Huie, and Langan (2023)
Abstract:
The species Anolis incredulus was proposed based on a single, poorly preserved specimen from the Sierra Maestra (mountain range) of southeastern Cuba. As its name suggests, this species was considered likely to raise doubts when it was first proposed, and it has been explicitly treated by some recent authors as a species inquirenda (a species of doubtful identity). Here we report on a second specimen of Anolis incredulus discovered in the amphibian and reptile collection of the National Museum of Natural History (Smithsonian Institution) that was collected more than 100 years before the holotype. We describe this specimen in detail and compare it both with the description of the holotype of A. incredulus and with presumed closely related Cuban species, providing evidence that it matches closely with the former and is distinct from the latter, thus corroborating the status of A. incredulus as a valid species. We also score and measure the specimen for sets of morphological characters to make inferences about its phylogenetic relationships and ecology (structural habitat use). Our results indicate that Anolis incredulus is likely a member of a clade of mostly Cuban twig-anole species and that it is a member of the twig ecomorph category, although its reported green coloration suggests either an erroneous ecomorph assignment or a difference in color from that of most other species of Cuban twig anoles.
Dear AA community,
I have just recently returned back home to Slovenia, where I started a research position at the Jovan Hadži Biological Institute, Research Centre of the Slovenian Academy of Sciences and Arts. Although I have thus far studied topics as diverse as sexual selection (nephilid spiders), phylogenetics (cuttlefishes) and visual gene expression (deep-sea fishes and cichlids), I have always had a keen interest in anole evolution. With the new position in hand and certain questions in mind, it seems that the time is ripe to finally, slowly but surely, delve into anole research.
Topics I am most interested in concern sexual selection and maternal effects, but also phenotypic plasticity in general; the latter also from a molecular (transcriptomic) point of view. Since AA brings together anole researchers of all scopes, I was thinking of asking here directly . . .
Would you be able to point me in the right direction and suggest colleagues and research groups that tackle questions within the scope of the aforementioned topics?
Please don’t hesitate to email me directly (nik.lupse@zrc-sazu.si) if willing to discuss in more detail. Many thanks!
Sincerely, Nik Lupše
MCZ 36138, the holotype of Anolis roosevelti. Laszlo Meszoly, del. From Mayer and Gamble 2019.
We recently reported on the new U.S. Fish & Wildlife Service review of the status of A. roosevelti (spoiler alert: not good). And we mentioned that we’ve had a lot of posts on this species before, including a number of recountings of previous attempts to find the elusive beast. In turn, this post prompted Ray Huey to recount his own efforts. Here goes:
During my first summer at Harvard (1971), I joined Ernest Williams (my advisor) and two grad students (Preston Webster, Joan Roughgarden) on a trip to the Caribbean. This was my first introduction to the amazing Anolis lizards. We went to the Dominican Republic, Guadeloupe (magnificent), Puerto Rico, and then Culebra–discovered by Columbus–off the east coast of Puerto Rico.
In 1939, the U.S. Navy started using Culebra as a target for bombing practice. But is also the island where Anolis roosevelti, a “giant” anole”–was found, but last seen in 1931. Williams thought we should try to find the beast, even though it had probably been blown to extinction.
We arrived at the tiny town of Culebra Pueblo in late afternoon. The only hotel was full, but we found a small rental house run by Frank Slaughter. Frank was colorful. He had been a boat captain and had ferried Richard Levins and Harold Heatwole around while they were doing biological surveys on small islands near Puerto Rico.
Slaughter had a way with words. He referred to Levins as a “strange duck”: “When I was in high school, people were counting the number of hairs on the asshole of fruit flies. And here was Richard Levins, a grown man, still counting the number of hairs on asshole of fruit flies.”
Given that Levins was one of the premier evolutionary theorists of his era, we all howled.
Back to the business of looking for Anolis roosevelti. Williams asked Slaughter whether he’d seen any big green lizards on Culebra. Slaughter replied, “How big is big? Do you have to reach up to milk it?” Williams (who was usually formal, especially with strangers) was speechless. The rest of us had to work to keep from laughing. All things are relative, but some are more relative than others.
View of the Andean scrubland, the main habitat of the lizards of the Anolis heterodermus group. Credits: Rafael Moreno.
Several years ago, when I began my biology studies, I was taking a walk in an Andean scrubland near my hometown, Bogotá, and while admiring the twisted shapes of the shrub branches, I noticed a small bright-green elongated spot on a branch, which stood out from the surrounding vegetation. The spot looked like an altered vision produced by entheogenic substances. As I approached the spot, my anxiety increased because it was slowly rotating around the small branch while I was getting closer. But when I was close enough to identify it, my anxiety ceased. It was not a hallucination, but a lizard, an Anolis heterodermus!
Some years later, my anxiety returned when I thought about the future of those lizards due to the advance of a gigantic city hungry for concrete. We decided to investigate it by trying to document the dynamics of populations in scrublands surrounding Bogotá. Even though the city continued its inexorable growth, it seemed that these lizards had several strategies to face the loss and fragmentation of their habitat, but only if the urban development onslaught was not too strong. Thus, my anxiety ceased, but only partially.
A small sample of the huge phenotypic diversity in A. heterodermus y A. richteri. Credits: Rafael Moreno.
The dewlap is probably the most noticeable thing about anoles. For me, the best way to spot an anole is by the flash of color from the dewlap as a lizard displays. Without that, many anoles would remain cryptic amongst the vegetation. This seems to be the case for the lizards themselves as well. The burst of color and movement as the dewlap is rapidly extended is a wonderful device for attracting the attention of rivals and mates. It’s possible that the dewlap originally evolved as an attention-grabbing flag to augment an existing sequence of elaborate headbob movements in forested environments. These days, the dewlap is a complex signal component in its own right, often with a dizzying array of colours and displayed using a variety of movements.
Anoles aren’t the only ones with a moveable dewlap. The Southeast Asian Draco lizards have a dewlap, and again to back up the headbob movements that make up their main channel of social communication. There are many other parallels between Draco and Anolis lizards, but the similarities in how they communicate is something that particularly fascinates me.
Early on in my fieldwork with Draco, I started discovering species that didn’t seem to use headbobs as part of their social display. It seemed these species had lost the headbob entirely and instead concentrated all of their communication through the dewlap display. These species are a minority, but not by much. It was a puzzle. These Draco had lost a central and complex element of their communication in favour of something that was seemingly more basic. Communication biologists are often fixated on trying to explain how animal communication becomes more elaborate over evolutionary time, but less attentive to why complexity subsequently becomes lost. These Draco lizards were an excellent case study.
Draco melanopogon (photo above) only communicates using the dewlap, whereas Draco sumatranus (opening banner photo) relies on both headbobs and the dewlap, just like anoles.
After nearly a decade of fieldwork on numerous species of Draco throughout Malaysia, Borneo and the Philippines, my trips stalled in 2020, as did the rest of the world. Celebrities had nothing better to do than write biographies, but my lockdown project was to focus on using the data I already had at hand to finally solve the curious case of the missing headbob.
It felt like an endless series of stay-at-home orders in Australia, and well into 2021 too. While the celebrities had gone on to finish their books and were now doing the zoom promotion circuit, my progress was hurdled by home-schooling two young children. We survived home-schooling in the end, and my attempt at figuring out why some Draco have lost the headbob has finally been published.
The evolutionary history of visual displays in agamid lizards
The first discovery is the headbob display is very ancient, evolving something like 130 million years ago or more. That’s before the evolution of Draco, and before the evolution of the anoles, in an evolutionary ancestor to both the iguanid (new world) and agamid (old world) lizard families. This was back in the age of the dinosaurs. Today, virtually all iguanid and agamid lizards use a headbob display or some variant of it in social communication. Which means the absence of the headbob in a handful of Draco species is very unusual.
The loss of the headbob from the social display of Draco is effectively a loss of complexity. A loss of complexity means a loss of “information potential.” Try writing a biography with half the alphabet. You might manage the following or something a little longer: “I was born. I paid taxes.” Thirteen unique letters in total. Obviously not the rich backstory you might hope for. Not because you hadn’t lived a fulfilling existence; rather you don’t have the language complexity to convey it in detail.
There are various reasons animals might lose complexity in their social signals. Perhaps the original need for a complex signal is no longer present. Perhaps the invasion of a new environment puts a brake on the level of complexity that can be accurately perceived. Or perhaps natural selection on other things, like body size, has made performing a complex signal too costly.
The beauty of having spent so much time in the field is the accumulation of a large library of data. By leveraging this information, I was able to test each of the above scenarios. The short of it is, Draco that have lost the headbob are unusually large species. Physically moving the head and body in a headbob display is more energetically expensive than pumping the dewlap in and out. It seems, then, that the physiological cost of performing the headbob became too great for these large species and they shifted to relying only on the dewlap for communication. This implies the communication system of these species is compromised, unless they have made up the loss of information potential somewhere else.
Draco without the headbob have more complex dewlap colour patterns. Each dot is a different species.
In fact, the dewlap itself tends to be more complex in Draco that have lost the headbob. Stealing a method for measuring complexity of anole displays, the dewlap of these Draco are more elaborately coloured than the average Draco. Unfortunately, this is unlikely to have been enough to fully cover the loss of the headbob. This means Draco that no longer use the headbob are relying on a constrained communication system.
The idea that the headbob is likely to be more energetically expensive than the dewlap was originally proposed for the anoles. It was used to explain the physiological basis for why Jamaican anoles might have evolved an innovation that allowed them to move away from a headbob-centred display in favour of one focussed on the dewlap. To be clear, the Jamaican anoles do still rely on headbobs in their social displays. But a rapid series of dewlap pumps features more prominently in their displays compared to the typical anole, like those on Puerto Rico for example.
It seems the dewlap has begun to supersede the headbob in anoles as well.
If you’d rather not slog through the paper itself, you can view a 12 minute video summary instead. If you would like to slog through the paper and can’t access it behind the paywall, drop me an email and I’ll forward you a free copy (t.ord@unsw.edu.au).
English translation now available!
Robert Hoogveld writes:
This year the Dutch society for Herpetology “Lacerta” celebrates its 80th anniversary. To celebrate, a lot of hard work has been done over the past year on a special edition of our journal, Lacerta, entirely aimed at anoles. We call it the Anolis special. It has become a 256-page book with contributions from Anolis enthusiasts and connoisseurs from the Netherlands, Belgium, Germany, Finland and Canada. It contains articles about, among other things, the study of anoles, behavior and welfare, travel reports with herpetological observations and species descriptions including the experiences of keeping in captivity.
At the moment the book can be ordered for anyone interested. website: https://nvht-lac
erta.nl/.On that website, everybody can order a copy for €20, including shipping world wide.