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Why Do Green Anoles Turn Brown? (5 Simple Reasons)

Why Do Green Anoles Turn Brown? (5 Simple Reasons)

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The purpose of this blog is to share general information and is written to the author's best knowledge. It is not intended to be used in place of veterinary advice. For health concerns, please seek proper veterinary care. In addition, as an Amazon Associate I earn from qualifying purchases.

Green anoles (Anolis carolinensis) are considered the most popular lizard species in the southern states.

Known for their color-changing abilities, green anoles are commonly, but inaccurately, referred to as American chameleons.

Make no mistake, anoles come from a different family than the Old World lizards. They’re actually closer to iguanas than they are to true chameleons.

Chameleons change colors to match their surroundings, green anoles don’t. So, why do green anoles turn brown?

In this article, we’ll discuss several factors that may cause green anoles to change color. We’ll also share some tips to help your anole return to its original color.

Let’s get started!

Why Do Green Anoles Turn Brown?

Crested Puerto Rican Anole Showing Off It's Dewlap

Green anoles are able to turn from light green to brown. There is hardly any variation between the colors, which is different from what true chameleons display.

Most true chameleon species are able to display a wide range of color changes. This process is usually slow and aimed at matching the color of the background.

Green anoles, on the other hand, can change colors in less than 30 seconds!

At this point, scientists know exactly how green anoles change color. What remains a mystery is why they do it.

What We Know So Far

Fortunately, there’s one consistently supported hypothesis that links color change with stress. Green anoles change color depending on how stressed they are. This stress could be psychological, physical, or environmental.

Another widely supported theory claims that green anoles change color due to social signaling. This becomes apparent when male anoles are about to fight or during behavioral displays between male and female anoles.

Some scientists say they do it for thermoregulation, too. However, most studies have largely debunked this theory.

5 Reasons Why Green Anoles Turn Brown

Brown Anole Profile

Here are five of the most common reasons green anoles turn brown.

1 – Unfamiliar Territory

One of the most common reasons anoles turn brown is unfamiliar territory. Green anoles can become distressed when introduced to a new enclosure.

This can be made worse if the terrarium isn’t suitable for their habitat. Anoles are tree-climbing lizards. They enjoy high enclosures with vertical branches and live plants.

Once you set up the terrarium, anoles will still take time to adjust to the new surroundings.

Even with repeated efforts to make the anole feel comfortable, expect it to be doubtful. Remember, to anoles, you’re just one giant predator.

Anoles aren’t as smart as other lizards. You should be patient and rest assured that your anole will eventually get used to the new environment.

2 – Parasites

Anoles aren’t known to get ill. However, they’re usually riddled with parasites when you capture them from the wild. Some are also infected when you buy them from the pet store.

Once you get a green anole, make sure you find a good reptile vet. This will help you quickly diagnose and treat any parasitic infections.

Roundworm, pinworm, and hookworm are the most common types of intestinal parasites. They cause weight loss, vomiting, diarrhea, and low appetite.

Anoles with a parasitic infection will almost always turn brown. If left untreated, it could cause more complications.

In order to prevent parasitic infections, make sure the terrarium is always clean. Don’t forget to take new anoles to the vet before introducing them to the enclosure.

3 – Mood

Anoles are active and inquisitive reptiles that love to climb. If they have no climbing areas in the enclosure, they’ll quickly get bored.

Boredom causes stress, and your anole will likely start turning brown and not move as often.

Even if there are some climbing areas, you still need to be mindful of the landscape of the terrarium.

Green visuals, live plants, and branches can mimic the anole’s natural habitat. This will make the anole feel more at home and less stressed out.

4 – Territorial Aggression

It’s best to keep your anole alone if you’re a beginner. However, anoles can also live in groups if the rest of the anoles are all females.

If another male is introduced to the enclosure, this will cause territorial aggression between the two males.

The males will attempt to display dominance and chase the other male away. If the other male chooses to face his rival, a fight will break out.

This immense stress will cause the anoles to turn brown. You’ll notice that a fight is about to break out if you see the males flaring their dewlaps and bobbing their heads.

Interestingly, scientists noticed that the victorious anole is usually back to green by the end of the battle. The defeated anole, on the other hand, remains brown.

This was one of the most significant observations that tied color changes to the level of stress.

5 – Temperature

Anoles are often seen green in the summer and brown in the winter.

This was originally associated with thermoregulation. Scientists believed that anoles turn brown on cold days to regulate their temperature.

However, this was debunked and contradicted in several new studies. The reason green anoles turn brown in the winter is simply that they feel cold.

Keep in mind that anoles prefer humid environments and warm temperatures. Experts say you should keep the top of the enclosure warm (85ºF – 90ºF) and the bottom cool (75ºF – 85ºF).

The correct temperature in the enclosure will allow your anole to become more active and easily regulate its temperature throughout the day.

How Do I Make My Anole Green Again?

Carolina Anole

Anoles turning brown is generally an indication of stress or mood changes. To make your anoles turn back green, you can try the following:

Expanding the Enclosure

It’s a common mistake for new owners to place the anole in a small enclosure. A small terrarium will immediately put your anole through fear and stress.

As a general rule, you should have an enclosure that’s no less than ten gallons. Ten gallons will also be suitable for two anoles, although the bigger the better.

If you’re getting three or more anoles, consider 15 or 20-gallon terrariums.

Another thing to keep in mind is the height of the enclosure. Like we said before, anoles love to climb. Terrariums should be around 20 inches high, with climbing areas reaching the top of the enclosure.

Finally, don’t forget to add a screened lid to cover up the enclosure. Anoles can easily make their way to the top and escape.

Improving the Environment

A terrarium with greenery and climbing areas isn’t enough to keep anoles relaxed. If your terrarium is missing one of these things, it may affect their quality of life.

  • Basking area
  • UV lamps
  • Heating lamp (cold climates)
  • Hygrometer
  • Thermometer
  • Tropical substrate (bark, soil, coconut husk…etc)

Removing Hostilities

As we mentioned above, two male anoles can’t live together unless you have a huge terrarium with two basking spots and many females.

If you add two males in a small enclosure, they’ll be in a constant state of stress. The submissive male will always be in the “fight or flight” mode.

Even if the submissive male doesn’t die from fighting, he’ll die from the constant stress he’s enduring.

Finally, cats and dogs frighten anoles. Make sure the pets don’t try to enter the enclosure or stick their faces too close to the terrarium.

Immunity Boosters

Since stress seems to be the leading cause of color change, immunity boosters can help keep your anole green.

You can try Reptaid to boost the anole’s immunity. These herbal blends usually contain antioxidants and other purifiers that rid the body of harmful contaminants.

If you’ve recently brought a green anole home, giving it an immunity booster can promote vitality and reduce physiological stress.


Here are some of the most frequent questions we received.

Can brown anoles turn green?

Bark Anole

Green anoles tend to change colors for a variety of reasons. If a green anole turns brown, it can switch back to green.

Brown anoles, on the other hand, can’t change their color to green. They can only change to darker shades.

Can green anoles change into colors other than brown?

No. The combination of pigment cells in green anoles allows it to change from green to brown and vice versa.

However, there are a few exceptions. Blue-phased green anoles lack xanthophores. This results in a baby blue or pastel blue hue. These anoles are rare and generally don’t change colors.

Another rare specimen is the yellow-phased green anole. These anoles lack cyanophores, so they’re typically yellow with brown patches.

Why is my green anole always brown?

If you’ve tried everything and your green anole is still brown, you should take it to the vet for further inspection.

The brown color is generally an indication of stress, but it can also mean your anole is severely ill.

Other than parasitic infections, anoles are usually hardy lizards that don’t get sick often. However, they can develop metabolic bone diseases, mouth rot, or respiratory issues.

If your anole is brown and you notice black spots behind the eyes, take your anole to the vet immediately.

Final Thoughts

Green anoles can morph from green to brown depending on their mood. Other factors can also make anoles change colors, including temperature changes and social signaling.

If your anole turns brown, it’s most likely going through heightened stress. Try expanding its enclosure, removing hostile males, or taking it to the vet to check for other health problems.

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