As I photographed an A. carolinensis displaying high on a tree trunk, an A. sagrei popped out about 5 feet below and countered with a display. Before he could advance on the green anole male above, another male A. sagrei advanced to challenge. The two A. sagrei got in each other’s faces, but did not actually lock in combat. Suddenly the first A. sagrei broke off and advanced up the tree to confront the male green anole. There was a lot of counter displaying but not as fierce as just performed by the two brown anoles. Eventually the green male retreated further up the trunk, stopped to display once before disappearing around the other side.
As an evolutionary biomechanist that is half in the Losos lab, I naturally dabbled in studying anoles during my first semester. I never presented my research, and have since moved on to other animals, but I thought you might like to see what I found.
Thom’s work on head shape shows a great amount of variation in the jaw length and width among anoles, and we wondered if the shape had an effect on jaw function. I was looking for differences in feeding behavior between the short-snouted Anolis sagrei and the pointy-snouted Anolis carolinensis. I placed a cricket on a leash, put it on a wooden perch inside a plexiglas container, put the lizard on the perch at the other end, and filmed the result.
Here are some videos of one sagrei attack:
sagrei- Front view
And here is a video of a carolinensis:
carolinensis- Side view
Based on my limited dataset, it looks like the sagrei keep their heads low on the perch while they make an attack-dash consisting of 1 chomp. They hold the prey in their mouths for a while before they begin chewing. Carolinensis get very close to the prey, pause, raise their heads up, and stab their jaws downwards without moving their hind legs.
By the way, if you need ideas on how to study anole biomechanics, I’d love to chat!
New minor color variants appear every once in a while, but it’s always interesting to find something completely different. This, to the best of my knowledge, is something completely different. I’ve found a few of these guys running around, and most had very similar colors. Considering their size (and presumptive age) I wonder if they were from the same clutch, or if a single breeding pair yielded this Punnett square anomaly.
Both of the males I had time to annoy/photograph (and the one female that was slightly less photogenic) exhibited the usual traits of A. sagrei. From the heavier build and shorter snouts, as well as the bolder attitude than our native carolinensis (I think the dewlap display was more for me than anything else; even when I was three feet away with a rather bulky camera, both males stood their ground), they would definitely fit the profile. But they’re not structurally an exact match to sagrei’s either. I don’t have a great head-on shot, but they’re narrower. Considering the insect population in the area I can’t say it’s from undernourishment. They move and jump more like carolinensis as well. They just don’t seem to be a differently-colored sagrei. Maybe there’s a little A. cristatellus in there.
I’m not the first one here to wonder what hybridization would yield and what cool little recessive traits could come from it, but I haven’t seen nearly enough specimens to suggest it’s a morph that may stick around- whatever it’s source.
“You’ve gotta see this!” my fiancé Mark called to me one morning. He was outside, which could mean only one thing: a wildlife encounter was underway. Living in a semi-rural neighborhood in Florida, you never knew what you would see, from a mated pair of Sandhill Cranes walking down the street with their young, to Gopher Tortoises excavating burrows in the front yard.
I walked downstairs to the concrete area under our elevated house where Mark was staring at something on the ground. I looked down to see a frog (Cuban Treefrog) with the tail of an A. carolinensis protruding from its gullet.
“I knew that lizard,” Mark said forlornly. Continue reading A Highly Anecdotal Account of a Most Remarkable Anole
Anoles have served as great model organisms in studies of adaptive radiation and how form and function are molded by selection, but they have also been the center-piece for some of the most interesting (and classic) research on how the brain modulates aggression to determine dominance. For example, work by Cliff Summers and his laboratory (among others) over the years has provided great detail concerning how adrenal catecholamines and glucocorticoids, produced during “stressful” aggressive interactions, interact with serotonergic activity in the hippocampus to determine social rank. These neuroendocrine processes are outwardly expressed, in a sense, by the familiar eyespot seen prominently during male green anole (Anolis carolinensis) interactions. The formation of the eyespot is stimulated by catecholamines, and the latency of eyespot formation is dependent on serotonergic activity, which is influenced by glucocorticoid secretion. Males that develop the eyespot sooner tend to be dominant, and once eyespots have appeared in one combatant, aggression in the rival tends to be inhibited. At least that’s the way it seems to work in A. carolinensis.
I will admit here that I used to be a little jealous of other anole catchers. This twinge of want was not necessarily due to any perceived greater intellectual merit of the research, nor to collecting successes in terms of sheer numbers of lizards. My envy stemmed from the fact that the stories were exotic, involving international travel to islands in the Caribbean both great and small, where supposedly the anoles practically fall out of the trees and astonish you with their diversity and abundance.
I would think to myself how comparatively boring my field work must sound: driving in a blue van with New York plates, weaving across state lines, searching for A. carolinensis, the lone species that lives on the continent — the Drosophila melanogaster of an otherwise thrillingly diverse genus. Can there be a more boring species than a lizard with the word “green” in its common name? Even the folks I meet while traveling in the field hint at mundaneness when I tell them what I am looking for: “Where you really need to look is on my aunt’s patio!” Yes sir, I know they often pop up in the begonias, but will they be there when I need them to be (because they never are)? Plus, I have to be in southern Georgia by tomorrow afternoon so I need anoles from this latitude today! Continue reading Anoles, American Style
It turns out that Anole Annals isn’t the only member of the WordPress.com stable that has a thing for our favorite lizard. While recently doing some tag surfing, we came across the following posts.
Catholic mom tells the gripping (or not) story of a green anole that went for a ride on the minivan windshield. You can probably guess the outcome, but the photos are nifty. Continue reading Anoles in the Blogosphere