This prototype video from a nature center in Bellaire, Texas has a degree of charm and entertainment, but a few factual errors and some unexpected historical/geopolitical statements. Still, it’s nice to see anoles chosen as the subject of their first video in what could be a series of micro-documentaries. More on the video and anoles at this website.
No, Ze Frank hasn’t created a True Facts about Anoles video–though surely that’s in the works (check out his list of videos). But he does have a very good one on camouflage and mimicry, and anoles make numerous appearances. For the record, my favorite True Facts is the one on chameleons.
Anolis allisoni, Photo by breslauer iNaturalist
Cities are hot. Because of the urban heat island effect, urban environments tend to be significantly warmer than nearby non-urban environments. For ectothermic organisms, like lizards and insects, elevated urban temperatures create thermally stressful conditions. It might be unsurprising then that researchers have documented an increase in thermal tolerance in urban animals (e.g., City Ants Adapt to Hotter Environment). These studies point to the ability to cope with elevated urban temperatures as a critical aspect of persisting in urban environments.
Although there is evidence that the urban environment shapes adaptive thermal tolerance in Anolis lizards at the genomic level, it is also possible that anole species that thrive in hot urban environments have an innate ability to do so due to local adaptation in their ancestral habitat (i.e., forests). In fact, an analysis of patterns of urban tolerance across Caribbean anoles found that species that experience hotter and drier temperatures in their native ranges and those that maintain higher field body temperatures tended to be the ones that do well in urban environments (Winchell et al. 2020). And when researchers looked at genomic variation in Cuban species not found in urban areas, they identified genes associated with thermal sensitivity (Akashi et al. 2016), suggesting tolerance of different thermal environments may be encoded at the genomic level. But does this mean that some anoles are predisposed to tolerate hot urban temperatures based on the climate of their ancestral forest homes?
Kanamori et al. (2021) — “Detection of genes positively selected in Cuban Anolis lizards that naturally inhabit hot and open areas and currently thrive in urban areas” — set out to answer this question by examining the transcriptome of nine species of Cuban anoles that occupy different thermal microhabitats. Cuba is home to the largest number of anole species, with species diversifying to occupy distinct thermal and structural microhabitats. In their study, the researchers attempted to identify genomic signatures of selection in non-urban populations of species that thrive in urban environments in order to understand if there was something unique about the genetic background related to thermal tolerance in these species that enables urban colonization.
Of the nine species Kanamori and colleagues studied, three are found in naturally hot and open environments: A. allisoni, A. porcatus, and A. sagrei, representing two different branches of the Cuban anole radiation. These three species (and several of their close relatives) also thrive in urban environments both in Cuba (e.g., Havana) and in their non-native range (e.g., Miami, Florida).
Five other species are found in cool and deeply shaded forests: A. alutaceus, A. isolepis, A. garridoi, A. allogus, and A. mestrei. The last species, A. homolechis, is common in the shaded areas of forest margins.
Kanamori and colleagues examined a total of 5,962 genes and found genomic signatures of selection in 21 genes in the two main branches of species that contain urbanophilic species (A. porcatus & A. allisoni, and A. sagrei), but did not identify selection in the same genes across the two lineages. In other words, these closely related species have found unique genomic pathways to deal with the hot and dry forest environments in which they thrive. This finding suggests that the predisposition to tolerate hot urban environments is determined by different genes in different anole species, and raises the possibility that further local adaptation to urban thermal environments may also be lineage specific.
When the researchers looked at the functional associations of the genes under selection in each species, they found that they were related to stress responses, epidermal tolerance to desiccation, and cardiac function. All three of these biological functions are implicated in maintaining appropriate acclimation responses to thermal stress in anoles. These findings implicate ancestral selection on stress responses, perhaps in response to thermal or ultraviolet radiation, as potential factors influencing tolerance of anoles in urban environments. Further exploring the importance of these functions will shed light on their role in the initial tolerance of urban environments upon urban colonization and adaptive modification as urban lineages persist.
Read the full paper here:
This post was cross-posted on the blog “Life in the City” — check it out if you want to learn more about urban evolution!
Photo by Alan Franck, iNaturalist
Hello again! Thank you so much for coming back. I know the post times have been a little bit off, but I’ve been working on some things and hopefully will be able to share one of those soon.
Anyway! I decided to pick another crown-giant for today and it is Anolis garmani, the Jamaican Giant anole. This anole is native to Jamaica, but has been recently introduced to the Cayman Islands and, (say it with me) Florida. Male Jamaican Giant anoles have an SVL of 131 mm, usually closer to 100 mm and females, 80 mm.
Photo by Tom McLellan
They are bright green with yellow dewlaps, and males have a dorsal crest of pointed scales. Unlike other crown-giant anoles, the Jamaican Giant anole has a proportional head size and shape to its body.
Photo by J. Burke Korol, iNaturalist
Smaller males are allowed to share and occupy the territory of larger male Jamaican Giant anoles. The larger males may even mate with the smaller ones, but once they grow over ~104 mm, they have to find their own tree. Mating, from beginning to end, takes about 25 minutes (Trivers 1976).
A set of observations, recently published in Austral Ecology, noted six different species of day gecko (Phelsuma spp.) using artificial light at night (ALAN) to engage in nocturnal activity (e.g., foraging, courtship, and agonistic behavior). Lizards of this genus are widely believed to be primarily diurnal, however, their propensity to colonize both urban and highly-modified habitats, as well as establish invasive populations within novel landscapes, suggests they are a taxon that is quite flexible and adaptable.
A blue‐tailed day gecko, Phelsuma cepediana, foraging for insects under a fluorescent light in Mauritius. Photo credit J. L. Riley.
Keen readers of the Anole Annals will recall several posts about the effect ALAN can have on anoles, including its impact on physiological stress, metabolism, invasive potential, and reproductive output. With many accounts noting the costs and benefits of shifting diel cycles and daily activity period, but also the general impact light pollution may have. No doubt, there remains a lot of research potential to examine similar questions for the many Phelsuma species across their native and invasive ranges.
Reunion ornate day geckos, Phelsuma inexpectata, engaging in nocturnal activity under a fluorescent light inside a bathroom in Manapany-Les-Bains, Reunion (A,B), including courtship behavior (C). Photos credits C. Baider and F.B.V. Florens.
The observations that led to this note came from nine researchers working in various sites, locations, and projects across a number of archipelagos spanning the Indian Ocean and over several years. As with many natural history observations, most of these accounts began with a researcher – who was no doubt occupied with an entirely different task – seeing something out of the ordinary, snapping a picture and jotting down some quick details, and carrying on with their work. A great reminder to never leave home without your trusty notebook; digital or otherwise. Then later on, sometimes much later, this information regarding “something weird you saw” is shared between colleagues, sometimes met with an “oh ya, I saw that too, different species, different location, but the same thing,” and from there, patterns emerge and collaborations bear fruit.
Over the years, Anoles Annals has featured a number of posts related to day geckos, with some keener anolologists expressing the feeling that these colorful, charismatic, and adaptable geckos could be seen as “honorary anoles.” A compliment, surely, the geckos would appreciate and reciprocate toward anoles, if given the chance. Despite their stunning appearance, long history of public awareness, and ability to sell car insurance, there remains a lot of information we do not know about day gecko behavior, biology, and ecology. We hope this natural history note will prompt further research interest into this enigmatic group of lizards.
Table 2 from Hsu et al. showing the survival rates of lizard eggs exposed to saltwater
In PLOS ONE
Hsu, Lin, Liao, Hsu, and Huang
Dehydration and hypersalinity challenge non-marine organisms crossing the ocean. The rate of water loss and saltwater tolerance thus determine the ability to disperse over sea and further influence species distribution. Surprisingly, this association between physiology and ecology is rarely investigated in terrestrial vertebrates. Here we conducted immersion experiments to individuals and eggs of six lizard species differently distributed across Taiwan and the adjacent islands to understand if the physiological responses reflect the geographical distribution. We found that Plestiodon elegans had the highest rate of water loss and the lowest saltwater tolerance, whereas Eutropis longicaudata and E. multifasciata showed the lowest rate of water loss and the highest saltwater tolerance. Diploderma swinhonis, Hemidactylus frenatus, and Anolis sagrei had medium measurements. For the eggs, only the rigid-shelled eggs of H. frenatus were incubated successfully after treatments. While, the parchment-shelled eggs of E. longicaudata and D. swinhonis lost or gained water dramatically in the immersions without any successful incubation. Combined with the historical geology of the islands and the origin areas of each species, the inferences of the results largely explain the current distribution of these lizards across Taiwan and the adjacent islands, pioneerly showing the association between physiological capability and species distribution.
Photo by Jorge Velez-Juarbe, iNaturalist
Happy Anole Day!
Here’s another crown-giant anole, Anolis cuvieri, the Puerto Rican Giant anole.
The Puerto Rican Giant anole is, as the name suggests, native to Puerto Rico. These anoles typically have an SVL of 132 mm, and both sexes have large tail crests. While these bright green anoles can turn darken and turn brown, this species also has a rare brown morph! Juvenile cuvieri are grey-brown with striping and shift to their signature green when they mature.
Photo by Graham Reynolds
They eat insects, mainly beetles, moths and butterflies, and also occasionally fruit, snails, birds and of course, other anoles.
Photo by sas103, iNaturalist
Puerto Rican Giant anoles prefer rainforest and can be found where there are lots of large trees together.
It’s invasive eat native time again here in Florida, where this poor but brave male green anole somehow found himself in a battle with a giant invasive gecko, Phelsuma grandis. Check out the video on ladywildbones’ Instagram page.
Phelsuma grandis is native to Madagascar, but has been introduced to South Florida as well, where several breeding populations exist in the Florida Keys.
They eat insects, fruit, nectar, and any animal that will fit into their jaws, including anoles! Like anoles, Phelsuma are aggressive, territorial, and fast-growing. They are the ultimate Florida invader, though rivaled in success by the green iguana.
We can probably expect to see more Day Gecko/Anole confrontations as the geckos increase their population.
Photo by Lindsey Swierk
Although most people use “personality” to describe human characteristics, animals also exhibit personality traits, which behavioral ecologists categorize as aggressiveness, exploration, activity, sociability, and boldness. Each personality trait is linked to inherent trade-offs that could affect one’s overall fitness, and may differ between the sexes due to different life history strategies. Boldness is a personality trait that includes behaviors such as risk-taking, response to predators, and resistance to being handled. It is assumed that bolder individuals are more likely to “take chances” and forage under predation risk compared to less bold individuals, whereas less bold individuals may spend more time scanning for predators and less time foraging.
Austin Carriere (The University of Oklahoma), Dr. Lindsey Swierk (Binghamton University – SUNY), Dr. Bree Putman (California State University San Bernardino) and I investigated the sex differences in the trade-offs between boldness and predator avoidance in water anoles (Anolis aquaticus), using the voluntary shedding of the tail (tail autotomy) as a proxy for predation risk. This project involved a two-year mark-recapture study, morphological data collection, and behavioral trials. We conducted and recorded boldness trials in the field for all captured adult anoles, and we analyzed the video footage in the lab. We quantified boldness as the latency for a lizard’s head to emerge from a refuge into a novel environment.
Fig 1. Adjusted survival curves showing how tail break (yes or no) affected time to head estimated from the Cox proportional hazard model in a) female and b) male water anoles. Survival rate is the proportion of individuals still in the refuge.
We found that there were sex-differences in the costs of boldness, as tail autotomy was positively associated with boldness in males but not in females. Tail autotomy has been shown to have serious fitness consequences in lizards; therefore males likely suffer a higher cost of boldness. We also found that males tended to be more likely to show evidence of tail autotomy. Our results could be due to the fact that lizards exhibit a polygynous mating system, wherein males defend territories to acquire mates, and so males may exhibit bolder behavior to increase their reproductive success. However, the trade-off of boldness in males is the higher probability of tail autotomy, probably due to increased exposure to predators or more involvement in aggressive encounters with conspecifics. Our study contributes to the understanding of sex differences in behavior within an ecological context.
Source: Talavera, J.B., Carriere, A., Swierk, L., Putman B.J. Tail autotomy is associated with boldness in male but not female water anoles. Behav Ecol Sociobiol 75, 44 (2021). https://doi.org/10.1007/s00265-021-02982-w
Photo by Karl Guyton II
Hi!
Welcome back. I lost a family member and took a break, but I’m back now and thank you for coming back.
I picked the Cuban Knight Anole for today because there’s just so much anole to love.
Anolis equestris are crown-giant anoles and the largest known species of anole with an SVL of 10-20 cm in males and 9-17 cm in females. Their tails can be about twice their body length. They are territorial and will gape and display at perceived threats, while raising its body.
Cuban Knight anoles are native to Cuba, but have since been introduced to places like Turks and Caicos, Florida, Hawaii and the Canary Islands.
Photo by Ultra Violet
These large anoles eat pretty much whatever they want to, including the usual anole fare like insects, nectar, other smaller lizards, and fruit and plant matter. They are actually able to pass on viable seeds! Cuban Knights have also been seen eating other animals that are smaller than themselves, like birds, scorpions, and frogs.
Photo by Paul Richards
Both males and females have dewlaps, which for this species have no pattern and are pale pink. There are 11 subspecies of the Cuban Knight anole, including A. equestris poitor, also called the Blue Beauty for its blue colouring that becomes more prominent and overt in its dark phase. These are only found in Cayo Santa María, an island off Cuba’s north central coast.
Photo by Jesús Reina Carvajal
Thanks for reading!
Here’s a video of a female digging a possible nesting site for your time.
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