Bonnie Kircher found this image inside the cover of Florida’s Fabulous Reptiles and Amphibians. Pay close attention to the last lines of the quotation and you will realize that this is a most well-placed anole photograph. 
Battling brown anoles. Photo by Karen Cusick
Over on Daffodil’s Photo Blog, Karen Cusick has documented a knock-down, drag out fight between two brown anoles (which we have elsewhere suggested should be re-branded as “festive” anoles). Check out the dorsal and nuchal crests!
Game: find the snake (Elaphe sp) and the lizard (male Anolis sagrei)
Snake (Elaphe sp.) versus lizard (Anolis sagrei)
Last April and May, I was in Florida… not for holiday but in order to discover the “lizard word” during a field session with Ambika Kamath. For her Ph.D. project in the Losos lab, we collected data on the spatial use of male and female Anolis sagrei to determine the reproductive system of this species. I was surprised when I realized how easy it is to observe these little guys directly in the field! I was really excited to see them mate, fight, display and eat: it was incredible! But the more impressive memory is when I saw a male A. sagrei being eaten by a baby rat snake. I wondered whether this was a really common sight… but I was told I was lucky that day!
The scene happened during a survey, when I saw this unmarked male displaying on a branch… but not on any tree: a tree occupied by a baby rat snake! It was thrilling to see the snake stalking the lizard in a sit-and-wait foraging strategy (as far as a snake can sit…). Even though five long minutes passed where the lizard had time to look around (photo 1), it still jumped on the very branch where the snake was waiting. A great occasion for the predator, who directly started to bite and wrap his body around the lizard whose helpless bites and dewlappings had no effect on the outcome of the fight (photo 2 & video).
After this, I wondered what the mechanisms of predatory detection and avoidance in lizards (including the tail loss ability) could be. Indeed, during predator-prey encounters, there is a transfer of information between them in the form of signals (e.g. auditory, chemical, visual) which may directly modify the outcome of the encounter. Anolis lizards possess a large and complex behavioral repertoire which consists mainly of visual signals (e.g. dewlapping, push-up, head-bobbing) that are used during social interaction, but also in encounters with a predator.
Leal and Rodriguez-Robles in 1997 showed that Anolis cristatellus may rely more on behavioral signals than on flight to avoid predation. It is indeed what I saw: the male lizard displayed to the predator… But I still wonder why this little guy suddenly jumped directly on the snake! Is it possible that he displayed to me and that in front of two potential “predators,” the lizard focused only on the first (or biggest) one that he saw? Apparently, this lizard was more afraid of me than of the snake… wrong choice, I was not going to eat him!
Then, the last day of my field work, I also saw a female cardinal with a big A. sagrei male in her beak… really strange… but I think that the “lizard world” has not finished to surprise me!
Leal, M. & Rodriguez-Robles, J. (1997). Signalling displays during predator-prey interactions in a Puerto Rican anole, Anolis cristatellus. Animal Behaviour 54(5), 1147–54. doi:10.1006/anbe.1997.0572
Parallel evolution and convergent evolution are big themes within anole biology, so our lab was excited to discuss a new paper by Thorpe et al looking at these concepts in Lesser Antillean anoles. The paper focused on evidence for parallel evolution across seven small islands that contained both xeric and montane habitats with at least one species of anole split between the two habitats. Xeric habitats tend to occur along island coasts and are hotter, drier, and have less canopy cover, while montane habitats occur in the interior of islands and are cooler and wetter. There are many physical differences consistently found between the anoles associated with each type of habitat, even within a species; perhaps the most obvious examples are the repeated differences in skin color and pattern between habitats, beautifully illustrated in the first figure of the paper.
Figure 1 from Thorpe et al, showing the repeated evolution of characteristic xeric and montane color patterns in the Lesser Antilles
Thorpe et al. set out to conduct tests of parallel evolution among seven anole species using 18 phenotypic traits that vary between habitats, including both morphological and pattern measurements. In addition, they used mitochondrial DNA sequencing to produce a new phylogeny of these species and control for phylogenetic interference in their comparisons. The authors first used a principal components analysis to confirm that the major source of climatic variation is found within each island and between different habitats, rather than across different islands. The authors found convincing evidence for parallel morphological evolution in multiple phenotypic traits, especially those associated with skin pattern and hue: anole populations in xeric habitats consistently converge on a grey skin color and those in montane habitats converge on green. Thorpe et al. also go on to suggest that divergence in coloration may be the result of signal optimization in environments with different chromatic backgrounds (characterized by variance in background vegetation or sun exposure). The authors describe a possible evolutionary scenario in which an anole population first colonizes the coastal areas of each island after a dispersal event, and then rapidly expands into the interior montane areas of the island and adapts to new conditions there. Given the constant concern of climate change, repeated evolution in response to different climatic conditions may offer hope that anole populations can respond to rapid environmental change.
The most famous story of parallel evolution in anoles is the convergent evolution of ecomorphs across the islands of the Greater Antilles. This paper offers the tantalizing possibility of another type of convergent evolutionary pattern, this time within species but across habitat types. The smaller islands of the Lesser Antilles may be too constrained to allow for speciation driven by ecomorph specialization, but could still promote significant population divergence across habitats. More information on the adaptive differences between these xeric and montane populations, along with characterization of their genetic structure, could shed light on these possibilities. Based on these results in the Lesser Antillean populations, there is also the possibility that this type of xeric and montane divergence exists within species in the Greater Antilles, and fine-scale studies of population structure could reveal another level of convergent evolution in those species.
Thorpe, R. S., Barlow, A., Malhotra, A. and Surget-Groba, Y. (2015), Widespread parallel population adaptation to climate variation across a radiation: implications for adaptation to climate change. Molecular Ecology, 24: 1019–1030. doi: 10.1111/mec.13093
And you’ll never guess what happened next! Something that I’ve never experienced in all my years. But I don’t know how to paste a video from Twitter into WordPress, so you’ll have to go to casa martin’s Twitter page to find out.
People pay a lot of attention to the color of a anole’s dewlap, but it’s often forgotten that the perceived color of the dewlap is not just a function of the light that reflects off of it, but also the light that at least sometimes shines through it!
These are two views of the brown anole taken minutes apart from opposite sides of the tree (the lizard was in the same spot, the photographer (me) moved.
For more on this topic, see what Manuel Leal had to say a while back on Chipojolab.
Photo by Jill Davidson-Guillen.
Jill Davidson-Guillen of Boca Raton, Florida, had an unexpected guest when she went swimming in her backyard pool last week. She said that she routinely finds curly-tailed lizards in the pool, but this was the first knight anole.
Ms. Ann-Ole thanks local herpetologists. From the Wild Amelia Facebook Page: Many thanks to herpetologists Mark Beshel (far left) and Caleb Bress (far right) of the Jacksonville Zoo and Gardens for their entertaining and informative presentation on the green anole at the last of the Wild Nites this Festival year. Who knew the green anole could be sooo much fun? Thanks also to our own Ms-Ann-ole! Photo–Scott Moore
The just completed Wild Amelia Nature Festival this year featured the green anole as its mascot. AA‘s friend, anole author Karen Cusick, attended and filed this report:
“The Wild Amelia Facebook page has photos and some info on a lot of the activities–releasing sea turtles, ecotours on foot, by kayak, and by segway, learning about bats with the Bat Lady, sunrise yoga on the beach, etc., so I hope that helped.
Although the green anole was the Critter of the Year, the main things specifically related to green anoles were: the green anole presentation by the people from the zoo (along with the person in the anole suit); a couple of booths at the expo that featured some pictures and books about anoles and other lizards; the kids’ activity where they got prizes for going around answering questions about anoles; and the festival tee shirts with the anole logo. I noticed that the person in the anole costume was also on hand to congratulate two children for becoming Seashore Junior Naturalists.”
Karen also nabbed two photography awards for the photos below. Congratulations, Karen!
Award-winning photo by Karen Cusick. First place in “Other Fauna” category for non-professional photographers.
Another award-winning photo by Karen Cusick. First place in “Bird” category
Here’s yet another three-legged lizard. This is a male brown anole (Anolis sagrei) from Abaco, Bahamas Despite missing most of its right leg (yes, the image is reversed), the little guy was fat and sassy and got around just fine. When he was let go, he even crouched down as if about to jump, before thinking better of it.
We’ve had plenty of previous postings on these three-leggers [for the full list, type “three-legged lizard” into the search bar on the right]. Always looking for more examples!
A good investment in the future. Photo by David Delaney
What moms eat and how much they eat can affect their reproduction, as well as many characteristics of their offspring – this has been shown in many different animals. But are these effects found in anoles as well? Two recently published papers from my lab address this topic in Anolis sagrei. In the first paper (coauthored with Matt Lovern), we housed reproductive females under two diet treatments (low vs. high amounts of food) for about four months in the lab. After quantifying reproductive variables (e.g., egg production, egg size, yolk steroid hormones) and offspring phenotypes, we showed that diet treatment had no effect on how many eggs a female produced and on allocation of steroid hormones to yolk, but females in the high-food treatment consistently produced larger eggs (resulting in larger offspring) than those in the low-food treatment. Also, regardless of maternal feeding treatment, egg size and the concentration of yolk testosterone increased over successive eggs that females produced.
We then incubated the eggs and raised the offspring under controlled conditions in the lab. Offspring produced by mothers in the high-food treatment had increased growth rates and survival; these patterns were driven by offspring size (larger size offspring in the high-food maternal treatment). We then performed a complementary study where we reduced maternal yolk investment by experimentally extracting yolk from eggs in order to determine if the effects of maternal diet were mediated by the amount of yolk invested into eggs. The effect of experimental yolk reduction on egg/offspring size, growth and survival mirrored the effects of maternal diet. These findings suggest that the maternal effects of diet on offspring growth and survival are likely mediated by how much yolk females allocate to eggs. This study provides evidence for a functional mechanism of diet-mediated maternal effects and demonstrates that there are fitness consequences of maternal diet.
Whether these effects of maternal diet are adaptive was the topic of the second study (coauthored by three undergraduate students in my lab). This “follow-up” study (conducted a few years later) was also a controlled lab-based study, where we housed mothers under similar “high” versus “low” diet treatments as described above (but the treatments were not entirely the same for logistical reasons). The resultant offspring were then raised reciprocally under the same two diet treatments that their mothers experienced. This experimental design (two levels of maternal diet and two levels of offspring diet) enabled us to test whether low food availability to mothers “prepares” offspring for low-food environments, and likewise, whether high-food maternal environments “prepare” offspring for environments with plenty of food.
Surprisingly, the effect of diet treatment on maternal reproduction was the opposite of that found in the first study. This time the number of eggs produced by females in the low-food treatment was half that produced by females in the high-food treatment; egg size was not affected at all by diet treatment. These contrasting results could be explained by the slightly different feeding regimes – in the first study, all lizards were given the same amount at each feeding, but the feeding frequency per week differed between treatments, whereas in the second study the feeding frequency was the same between treatments and the quantity of food provided differed between treatments.
Despite this, the primary finding of the study was that offspring survival was relatively high when there was plenty of food available to them (not surprising). However, offspring also survived comparatively well under poor food conditions, but only when their mothers also had little amounts of food during reproduction. These findings suggest that poor maternal environments might ‘prepare’ offspring for environments with little food resources.