Green anoles (Anolis carolinensis) don’t hibernate over the winter.
If you search for this info online, you’ll find conflicting opinions from educational resources.
This leads to confusion as if you’re an owner of a pet anole and you’re wondering if it’ll go dormant during the cold winter.
For instance, the Savannah River Ecology Lab at the University of Georgia states:
Yes, green anoles hibernate in colder regions of their geographic range, which extends from the Carolinas, throughout Georgia and Florida, to Alabama through Texas.
But a research paper done by ILAR at Oxford Academic says:
During autumn and winter, green anoles (adults and juveniles alike) are relatively inactive. They do not hibernate but may spend days or weeks, sometimes clumped together in large groups, in locations with protection from the weather (e.g., in tree cavities, under fallen logs).
Both of these sources are reputable, so what gives?
Here’s what I think.
Note that this article is opinion. Your views may vary. I’d love to hear your thoughts- please leave a comment on what you think!
Green anoles are popular in the pet trade and owners have experienced brumation, but full out dormancy? It’s somewhere between that and normal behavior. It’s like sleepwalking- not exactly active, but not fully dormant either.
But the majority don’t. Why is this?
It’s likely due to the ambient temperature not being cold enough to go completely into “full hibernation” mode.
Green anoles tend to become inactive and slow rather than completely hibernate and shut down, as you’d imagine with toads, or snakes.
This is called brumation. It’s not full out hibernation where they’re dormant. But they slow down their activity in all ways- eating, basking, hunting, etc. Torpor, sluggishness, slowness. Whatever you want to call it.
When grown in captivity, they have artificial lighting and heat, plus a food source to keep them going throughout the winter.
They don’t need to conserve their energy by going inactive since everything they need is provided. Thus, green anoles will rarely go dormant during the winter.
However, in the wild, green anoles need to prepare themselves for the cold season.
They feed throughout the summertime and will stop eating when the winter comes. This is because reptiles, in general, need sunlight to properly digest their food.
If the temperature drops, they can’t properly digest their meal.
So naturally, they won’t eat when the winter comes. They’re ectothermic and eaten food that’s not digested will rot inside their digestive system.
This is bad. And they know to avoid this.
In the winter, anoles will stop eating even if a meal is available.
They decrease their metabolic activity (running, foraging, walking, etc.) to conserve energy because of the lower caloric intake. Less moving around means less energy expenditure, which is necessary if they’re eating less.
See how it all makes sense?
This is probably why there’s confusion over whether or not they do indeed hibernate. It CAN happen, but it’s rare and will completely depend on the lizard and environment.
In a terrarium controlled by artificial sustenance, they probably will never hibernate.
Or at least, not completely. In the wild? They can go dormant or become extremely inactive since that’s their natural pattern.
This explains the reason behind the two perspectives.
What do green anoles do in the winter?
Green anoles slow down their metabolism by becoming inactive.
They don’t run around, hunt, or bask as much and will find a place to hide for many weeks.
Sometimes they’re doing this for extended periods as a large cluster of lizards. Other times it is just one anole.
They hide and expend as little energy as possible to conserve it because wintertime has minimal food as insects hide for the winter. There are also fewer sunlight hours for the lizard to thermoregulate.
So they do what they can to utilize little energy (calorie burn).
What happens when anoles get cold?
Green anoles will huddle up in large groups when they’re cold. They go dormant together and stop feeding around the same time.
This usually starts in the fall and both adults and juveniles will become inactive. If they’re running solo, they can find a location that protects them from the weather and become inactive for weeks.
When there are communal anoles, they may all go dormant together in large numbers. Both have been observed in the wild.
Green anoles run on a cycle and will exhibit the same behavior every season. If grown in captivity, they likely won’t enter this period of inactivity.
Do green anoles turn brown when cold?
Green anoles turn brown when stressed.
Being cold is stressful, especially when they’re hungry or don’t have enough light/UVB. They can’t eat right. They can’t digest food.
And they’re forced into hiding and conserving their energy until they can find a source of heat again. Turning brown for extended periods could mean that something is off in your tank.
Check the temperatures on both the “hot end” and the “cold end.” Check the humidity. Make sure there’s a small place for them to bathe and get water.
Oftentimes, the UVB light is the culprit behind a brown anole.
UVB lights are often placed at the wrong distance (the farther from the basking area, the weaker the UV).
They also get much weaker as they’re used, so they need to be replaced when the UV they emit is too weak.
Incandescent UVB (AKA compact incandescent or coil bulbs) which self-ballasts by screwing into fixtures or domes is also not as efficient as the standard T5 or T8 florescent bulbs. Mercury bulbs are excellent, but pricey.
So if your green anole is brown and not changing back, check the lighting first.
The small UVB bulbs don’t emit as much as the strip.
There may also be inadequate heat. Just like UVB, the distance of the bulb makes a difference.
When you take the temperature of your terrarium setup, use an in-tank probe that sits on the place the lizard basks- driftwood, branches, decor, etc.
Don’t use sticky ones that are on the outside and don’t use gauges that stick on the inside either.
The reading should be taken directly on the basking site. Or else it’s highly inaccurate.
probe on the area that the lizard basks (driftwood, branch, etc.).
Don’t rely on stick-on thermometers. The reading should be taken ON the surface where the lizard spends its time, or else it’s highly inaccurate.
These two reasons could be why your green anole is brown from the cold.
Do anoles hibernate in captivity?
This bearded dragon is going through brumation. Your anole should be similar in behavior:
As mentioned earlier, probably not.
The artificial lighting and heat you provide them in your tank are enough to keep them from entering dormancy.
This is what allows you to keep feeding them throughout the autumn and winter without hurting them.
Remember that they NEED UVA/UVB/HEAT to properly eat and digest their food.
NEVER feed your lizard when the temperatures are too low. The food won’t digest and will rot inside them.
What happens when a lizard gets too cold?
It’ll become sluggish and inactive. If it’s too cold, it’ll stop eating and enter “hibernation” as we discussed earlier on this page.
They can’t generate their heat- they must collect it from the sun, which is why providing adequate heating in the tank is a necessity.
When the temperatures are too cold, they go dormant and hide for weeks until food or light is available.
So always set up your tank with all the necessary supplies for your lizard.
No hibernation means more playtime
Since green anoles don’t go dormant during the winter, this means more time that could be used to enjoy it, right?
Rather than leaving it alone for a few months every year, you can now feed it, interact with it, or just watch it?
Do you have any questions?
Would you rather have a lizard that hibernates every winter? Post a comment and let us know your thoughts!