I wanted to share an observation of communal basking of the Green Anole (Anolis carolinensis) from the western Highland Rim of Tennessee. The locality is near the northern extent of their range in middle Tennessee. On a warm January day this winter, I observed six (6) individuals basking in close proximity along an exposed tree branch. The overwintering habitat was a south-facing road cut.
Has anyone else observed this type of “communal” basking of anoles, either in the Green Anole (Anolis carolinensis) or other species?
Latest posts by Anthony Brais (see all)
- Communal Basking of Anoles - January 18, 2019
- Hair-like Features on Green Anole (Anolis carolinensis) - July 28, 2018
James T. Stroud
Very cool! This is a common behaviour in most reptiles that brumate, but the first picture I have seen of it occurring in anoles. Those branches look more like exposed roots – do you think those lizards emerged from over-wintering in the root balls under a tree? Thanks for sharing, James
Dave
Tree root balls are definitely among the places I have observed green anoles spending longer cold spells [see my comment below].
Dave
I’ve observed communal basking by green anoles for decades, most often in early a.m. or on ‘warm’ winter days as you observed but sometimes also at optimum temperatures in summer.
In most cases the anole ‘community’ had formed around coveted nighttime/winter shelter, often house siding and metal objects like unused grills and junked cars. In warmer conditions they do seem to actually be socializing, if only to have arguments [generally females] ;}
This in Charlotte, NC and I’m fascinated to learn there are green anoles anywhere in Tennessee. Their range here seems to stop just north and west of Charlotte. Could the Tennessee populations be more cold tolerant and are they migrants from the Gulf coast?
Thanks for your post, and what a great website this is.
Anthony Brais
I do not know where the Tennessee population of anoles originated from. Their range in this part of Tennessee stops somewhere southwest of Nashville. This winter I have been looking to better define the northern range limit in this part of the state. Average January highs / lows in this part of Tennessee (Nashville) are about 47 / 28 degrees Fahrenheit compared to 51 / 30 degrees Fahrenheit for Charlotte. Anoles living on the Cumberland Plateau of Tennessee or in the East Tennessee mountains likely survive in an even harsher climate than the rural areas southwest of Nashville due to increased elevation.
Anthony Brais
There were numerous holes / crevices on the exposed soil face beneath the tree. I suspect those are over-wintering locations. I saw one individual basking just outside of a burrow to the left of the tree root. I want to re-visit this site to observe when the anoles emerge from their over-wintering burrows to bask.
Dave
Replying to both your replies [thanks for these],
I imagine there’s plenty of literature on the origins of given green anole populations, likely on this very site, I just haven’t searched yet. Too much time commenting, not enough researching I guess.
Anyhow your first comment supports what I suspected – some groups may be considerably more cold tolerant than others, and these in turn may be specific to areas west of the Appalachians. I’ve often wondered how other species like cottonmouth snakes occur much farther north and in much colder local climates in the Mississippi region than they do along the east coast.
Whatever the case there, the Appalachian barrier and Tennessee anole distribution you describe suggest a Gulf origin for their ancestors.
“Law of the Lizard”, the Smithsonian documentary this site alerted us to, deals almost entirely with tropical anoles but offers fascinating revelations on anole adaptability and evolution. I have no doubt our North American species is quite similar, right down to noticeable morphology differences in isolated populations less than a mile distant from each other.
The soil/tree root environment you describe sounds exactly like one I observed over a three year period. Absent human artifacts with better heat trapping and insulating properties, green anoles do seem to favor these combinations.
James (Skip) Lazell
Wow! I spent 4 years at The University of the South in Sewanee, TN, 1957-1961. Anoles were fairly common, but I never saw this. I went off 4every summer to collect anoles in the West Indies, sponsored by the MCZ, Harvard…. Of course, never saw this there either. Thanks! Skip
Chris Thawley
Recent research has shown that anoles do indeed experience selection for increased cold resistance due to cold winters, so it’s likely that northern populations of green anoles are adapted to the climate in these areas. Pop sci summary here: https://harvardmagazine.com/2017/08/green-anole-polar-vortex-lizards-evolution
Paper here: http://science.sciencemag.org/content/357/6350/495
Dave
Many thanks!
Chris Thawley
Another cool instance of communal basking in green anoles in a manmade structure here: https://www.inaturalist.org/observations/20113186
I count nine within 2 ft of each other!
Laurie
I live in coastal SC. The green anoles in my backyard often bask in large clusters. They overwinter behind my shutters, today I just counted 9 basking on one set of shutters. It is unusually warm today- 70 degrees. The lizards are loving it!
Mary Loucks
My question is, do they brumate when it’s too hot and dry outside as it is in Austin, Texas right now? I had a family of anoles living in my lantana, which were very active, but now they have disappeared. I keep hoping they will emerge again?