Check out this green anole photographed at the Archbold Biological Station in Florida by Nick Fletcher, participating in a Cornell University field trip led by Harry Greene.
Green anole. Photo by Nick Fletcher.
Photo by Nick Fletcher.
And here’s one more by Nick, taken a day later.
Photo by Nick Fletcher.
Spring is the season for spotting crown-giant anoles in Miami!
I was hosting (recently graduated Lacertid-ophile, although closet anologist) Dr. Robert Heathcote for a few days this week, and after his failed attempt at catching a Cuban knight anole (A. equestris) a fortnight previous, I had promised to deliver him another! Now, I imagine many AA readers may chuckle at someone foolish enough to promise a crown-giant observation (myself included). Much to my relief luck was on our side and we managed to spot not one, but TWO species practically on top of each other!
A Cuban knight anole (A. equestris) and Jamaican giant anole (A. garmani) perched within 1-2m of each other in Miami FL – April 2nd 2014, JStroud
Cuban knight anoles (A. equestris) and Jamaican giant anoles (A. garmani) are both non-native introduced species to south Florida.
A. equestris (left) and A. garmani (right) – habitat overlap in Miami FL, JStroud
St.Lucian Anole
I was recently in St.lucia travelling around photo-documenting the local Anolis luciae which seem to be rapidly being displaced by the invasive A. wattsi from Antigua. While exploring the southwestern town of Soufriere, I came upon a few specimens of this species in the backyard workshop of the sculptor host of mine.
I have showed the photos to a few herpetologists at UWI (St. Augustine) and they are as baffled as I am; for the closest-looking possibility, A. richardi, native to Grenada and the Grenadines, is not noted to have migrated this far north.
Any takes on what species it could possibly be?
From the pages of Sports Illustrated, 25 years ago today
That’s my thumb! Ain’t she a beauty?
A few months ago, I ran into Nicholas Dawidoff, the author of the fabulous new book Collision Low Crossers: A Year Inside the Turbulent World of NFL Football. Seeing Nicholas reminded me of the article he wrote for Sports Illustrated at the very dawn of his writing career, 25 years ago today. The article was on the then developing field of performance studies, measuring the sprinting, jumping, clinging and other capabilities of small ectotherms, and featuring none other than yours truly, as well as Ray Huey, Al Bennett, and Sharon Emerson. Written tongue-in-cheek, but accurately and respectfully, the article was a very nice overview of that emerging field of study. It’s worth checking out the article just to see the wacky pictures taken by the SI photographer sent out on assignment to Seattle and Berkeley.
Inexplicably, the article didn’t make the cover
If you followed the barrage of blogposts we wrote from SICB 2014, you might recall some discussion of the information actually conveyed by anole displays and dewlaps (1, 2). The upshot of these studies is that anole displays are complex. We see unexpected relationships between various traits and the probability of success in male-male competition, and different traits correlate with different measures of male success. A recent study by Steffen and Guyer (2014) adds to our growing knowledge of the information conveyed by different dimensions of multimodal anole displays. When viewed together with previous research, this study presents us with an even messier picture than before of how Anolis lizards communicate with each other.
Steffen and Guyer (2014) set up paired competitions between size-matched male Anolis sagrei in a lab setting, implementing two treatments–males either compete for access to a single perch, or for mating access to a single female. All interactions were recorded, and display behaviours–headbobs, push-ups, dewlap extensions–were quantified. Further, the spectral reflectance of both the centre and the margin of the dewlap (which can be strikingly different in A. sagrei) was also measured. The question asked by the paper was straighforward: which display and dewlap traits are related to an individual lizard’s status as a winner or loser of competitions?
In both competitive contexts, only two traits seem to be important–a composite axis of behavioural variation, and one of three composite axes describing the colour of the margin of the dewlap. Lizards who headbob, push-up, and extend their dewlaps more during competitive interactions are more likely to win than lizards who display less. Curiously, lizards with lower UV reflectance of the dewlap margin are more likely to win than lizards with brightly UV-reflecting dewlap margins.
Of the two variables, display behaviour was more highly correlated with the probability of success than dewlap margin UV-reflectiveness. I’m curious about how the two variables are themselves related–do lizards that display more also have less bright dewlap margins? The authors propose that a dewlap’s reflectance might relate to its conspicuousness, and it would be interesting to know if different individuals are conspicuous in different ways.
Each of the studies conducted so far on how anoles convey information to each other has examined different dewlap and display variables, studied different competitive contexts, and used different measures of male quality. It therefore isn’t surprising that we seem far from reaching a consensus on what the dewlap says.
Book cover from the Animorphs series book 1, The Invasion by K.A.Applegate.Published 1996
Photo from wikipedia
Recognize that Lizard?
I actually read this book a long time ago, I loved the series; basically the premise was that a bunch of children were given a space cube by an alien that allowed them to change into any animal for two hours. The kids would then use the abilities of these animals to thwart the various plans of a race of alien, mind-controlling parasitic slugs.The idea was original and the books were an interesting read too.
The picture on the cover is of one of the main characters morphing into a Cuban (specifically mentioned) green anole; unfortunately, I don’t remember what it was that he did with this morph.
A common concept in ecology is that predators have a strong influence on the behaviour of prey species. Anolis lizards have been used as a classic model system to investigate the effect of predator presence on the behavioural response of prey species. On small experimental islands in the Bahamas the manipulated introduction of curly-tailed lizards (Leiocephalus carinatus), a large terrestrial anole-predator, has resulted in brown anoles (Anolis sagrei) shifting higher up in the vegetation, presumably in an understandable effort to avoid being eaten (1, 2, 3). However, predator-prey interactions such as these which may shape community structure are often difficult to observe.
Here in Miami FL we have a rich and diverse, although largely non-native, lizard community. There are two species of “crown-giant” anoles, the Cuban knight anole (A. equestris) and the Jamaican giant anole (A. garmani), that could be potential predators of smaller anoles in the canopy of trees and upper half of tree trunks (although see Giery et al. 2013 for an empirical analysis that suggests this may not be the case). Additionally, there are several large, terrestrial lizards present which may be filling a similar role to curly-tails in the Bahamas.
Potential lizard predators in south Florida:
– *Red-headed agama (Agama agama)
– *Cuban knight anole (Anolis equestris)
– Jamaican giant anole (Anolis garmani)
– *Brown basilisk (Basiliscus vittatus)
– Spiny tailed iguana (Ctenosaura similis)
– Curly-tail lizard (Leiocephalus carinatus)
– Giant day gecko (Phelsuma grandis)
– Black and white tegu (Tupinambis merianae)
*Present at Fairchild Tropical Botanical Gardens
Earlier this afternoon, while taking a break from my office at Fairchild Tropical Botanical Gardens (a hot spot for any anologist visiting Miami; 1, 2, 3, 4) in a typical graduate student effort to put off work that I should be doing instead, fellow lab member Evan Rehm and I noticed some scuffling in a nearby bush. At around 2.5m, and admittedly on relatively precarious branches by this stage, sat an adult female African red-headed agama (A. agama) around 30cm from an adamantly motionless adult male Cuban brown anole (A. sagrei)! As we moved towards the bush the agama was quick to ungraciously thump itself to the floor, while the brown anole remained still. On closer inspection, it soon became apparent why both lizards were so high.
Adult male Cuban brown anole (A. sagrei) found ~2.5m high in Miami FL, supposedly following a predation attempt from an African red-headed agama (A. agama) – JStroud
The significance of tail loss/damage in a population is still debated. The classical view argues that high proportions of tail damage indicates high predation pressure, therefore prey populations are under high predation stress (1). Alternatively, high proportions of tail damage could indicate low predator efficiency, which would suggest prey populations are experiencing low predation stress (1, 2). But the debate doesn’t stop there! Having already lost a tail, a lizard may experience either a resulting increase or decrease in predation depending on the predator species and its associated foraging tactic (1).
The extent of tail damage is clearer in this photo. The lizard had autotomised the lower half of it’s tail however a secondary half-completed break is also evident – JStroud
African red-headed agamas (A. agama) are similar morphologically to curly-tailed lizards (L. carinatus), although are taxonomically distinct (Agamidae and Leiocephalidae, respectively). Predation of anoles by agamas in Miami has not previously been officially recorded, and the impact of these large predators remains unclear. Unlike in the Bahamas, there are multiple predators in the same geographic vicinity that anoles need to be aware of. For example, at Fairchild, brown anoles (A. sagrei) could be eaten from below by agamas, eaten at intermediate levels by basilisks and eaten from above by knight anoles!
South Florida is a tough place to be an anole!
Adult male African red-headed agama (A. agama) at Fairchild Tropical Botanical Gardens, Miami FL. The population of agamas is localised to the botanical gardens; the source remains unclear but is likely an introduction from the pet trade – JStroud
A juvenile Anolis bartschi scampers up a limestone boulder.
Recently, frequent Anole Annals contributor Martha Muñoz and I had the opportunity to visit Cuba as part of a licensed trip through the Harvard Museum of Natural History. During our two weeks on the island, we visited many localities and had the opportunity to photograph and observe some of Cuba’s most beautiful anoles. In the coming weeks, I’ll be spotlighting some of our favorites. All images presented are © Shea Lambert 2014.
First up: Cuba’s Western cliff anole, Anolis bartschi.
Photo courtesy Marissa Pierce
Anolis carolinensis. Photo taken by Kathleen Foster.
Anoles are the indisputable poster children of ecomorphology. Morphological, behavioral, and performance data support classification of Anolis species into discrete ecomorphs on the Greater Antilles islands. In a large part, the basis of this classification is due to variables (e.g. limb length) that relate to differing locomotor abilities (i.e. speed and/or stability) on the various substrates that comprise the different areas of the arboreal habitat. However, until recently, we knew nothing about how the muscles that power locomotion in these species relate to their ability to cope with the challenges of moving in these different microhabitats.
In a recent paper in Proceedings of the Royal Society B, we used a combination of electromyography and 3D high-speed video to examine the impact of perch diameter and incline on limb kinematics and muscle activity in Anolis carolinensis. Our previous study in the Journal of Experimental Biology found a number of kinematic changes (e.g. increased limb flexion and depression) associated with increased stability on narrow surfaces, and we hypothesized increased recruitment in the muscles associated with those movements. Interestingly, this was not the case. Despite considerable kinematic modulation with change in perch diameter (63% of the 32 kinematic variables were significantly affected by perch diameter), there was very little change in muscle activity (2% of the 100 muscle activity variables). This decoupling of kinematics and muscle function raises a number of very interesting questions relating to the sensitivity of these muscles to changes in operating length and the degree to which this species is specialized for a particular microhabitat. It also highlights the complexity of the physiological basis of animal locomotion and emphasizes the need for caution when attempting to infer motor control from kinematics and vice versa.
An additional result that may significantly impact identification of habitat preference in Anolis lizards relates to the importance of variability, as opposed to magnitude, of muscle activity in describing the differences in how this species handled the different substrate conditions. Specifically, the muscles examined were less variable on the broad perch compared to the narrow perch and on the vertically, as opposed to horizontally, inclined perch. Locomotor stereotypy is generally believed to reflect locomotor specialization, although reduced variation of in muscle activity may also be achieved as a byproduct of near-maximal muscle recruitment. However, we have little support for this second option, as the muscles were neither approaching maximal stimulation nor vastly different in overall magnitude or recruitment. Therefore the greater stereotypy of muscle activity seen in the green anole as it moved on the broad, vertical condition may reflect a physiological preference for tree trunks, rather than the narrower and shallower substrates that comprise (on average) the trunk-crown region to which it is traditionally assigned.
It is clear that there remains a wealth of knowledge waiting to be unearthed in the Anolis system and this paper barely scratches the surface. It emphasizes how little we understand about the complex nature of animal locomotion and the relationship between the muscles that power locomotion and the movements we observe in the field. And the possibility that variability of muscle activity might be a useful tool to identify functional preference for microhabitat is tantalizing and deserves further attention, especially if it can be applied usefully to mainland Anolis species. The remainder of my dissertation will focus on fleshing out these and other aspects of muscle function through the comparison of ecomorphs of the Greater Antilles.
Kathleen L. Foster & Timothy E. Higham. (2012). How forelimb and hindlimb function changes with incline and perch diameter in the green anole, Anolis carolinensis. Journal of Experimental Biology 215: 2288-2300. (DOI: 10.1242/jeb.069856)
Kathleen L. Foster & Timothy E. Higham. (2014). Context-dependent changes in motor control and kinematics during locomotion: modulation and decoupling. Proceedings of the Royal Society B 281: 20133331. (DOI: 10.1098/rspb.2013.3331)
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