If you’ve noticed your green anole taking on a brownish hue, you may be wondering why this color change is occurring. Anoles have the remarkable ability to change color, which serves important camouflage and signaling functions.
If you’re short on time, here’s the quick answer: Green anoles turn brown due to temperature changes, stress, adjustiong to a new environment, sickness, or preparing to shed their skin.
In this comprehensive guide, we’ll explore all the possible reasons your green anole is turning brown, when you should be concerned, and what you can do about it.
Temperature-Induced Color Change
Browning Due to Cooler Temperatures
Green anoles can turn brown when exposed to cooler temperatures. This color change is caused by chromatophores in their skin contracting and dispersing melanin pigments. Melanin causes the darker brownish hue that helps the lizards better absorb heat when it is scarce.
This adaptation likely helps green anoles survive during short cold spells or wintertime in warmer climates. Studies show the optimal temperature for most green anoles ranges between 28–35°C. Outside of this, they resort to color change for thermoregulation.
According to field researchers, the threshold for browning in most green anole species is around 10–16°C. Once temperatures exceed this threshold, their skin reverts to the brighter green color. This threshold can vary slightly depending on the natural climate of specific anole species.
For example, those living at higher latitudes with harsher winters can start browning at 18°C. Ultimately, the melanin pigments help the cold-blooded reptiles safely maintain body heat until warmer conditions return.
Browning Due to Warmer Temperatures
Higher temperatures can also induce temporary browning in green anoles. When temperatures climb excessively high for a prolonged period, above 40°C, the lizards once again resort to melanin for protection.
This time, the melanin shields their skin from harsh UV rays that grow more intense alongside the heat. Excess UV exposure could damage their cellular tissue and DNA, so the brown hue acts as natural sunscreen until conditions improve.
During these hot spells, green anoles also spend more time hiding in cooler shaded areas to prevent overheating entirely. They may cling to the undersides of broad leaves, hide in tree holes, or retreat to the ground cover below the canopy.
While the melanin protects their skin, these hiding behaviors help regulate their core body temperature, which can rise to dangerous levels in direct sunlight above 40°C. Once the ambient temperature drops closer to their ideal range at night, the green anoles will return to their regular habits and coloration.
Stress-Related Browning
There are a few potential reasons why your green anole may turn brown. The most common cause is stress. Here’s an in-depth look at why stress can lead to browning in green anoles:
Camouflage Response
When green anoles feel threatened or stressed, their bodies undergo physiological changes to aid in camouflage. Their green pigments fade, allowing the underlying brown colors to show through. This provides camouflage against brown branches or soil, helping the anole blend into its surroundings and avoid predators.
Reaction to Environmental Changes
Sudden changes in the environment can also induce stress in green anoles. This includes things like:
- Moving the anole’s enclosure
- Introducing new cage furnishings
- Changing light, heat, or humidity levels
- Loud noises or vibrations
The anole perceives these disruptions as threats. Its stress response kicks in, causing green pigments to recede and brown tones to become visible. This defensive coloring helps them feel less exposed during environmental shifts.
Poor Health or Old Age
Sometimes browning can signal issues with health or age. As reptiles grow older, their coloration often fades. Underlying brown hues emerge while vibrant greens dull. Illness can have similar effects. When sick, anoles conserve energy by letting green pigments fade. This unveils duller brown tones.
Check for other symptoms like lethargy, appetite changes, or weight loss if your anole seems to be aging or ailing.
Temperature Effects
Green anoles are cold-blooded, so their body temperature reflects ambient heat levels. In cooler conditions, these lizards grow darker to absorb more warmth from the sun. Lower temperatures can also trigger mild stress, inducing browning.
Ensure the enclosure stays warm enough, around 75-85°F during the day. Localized heating elements may help cold-sensitive individuals.
Overall Tips
Here are some tips to minimize stress and keep your green anole vibrantly green:
- Provide a suitably-sized enclosure with ample foliage and hides
- Maintain proper temperature, humidity, and day/night cycles
- Limit sudden environmental changes
- Keep their habitat clean and hygienic
- Offer a balanced, vitamin-rich diet
- Allow time to adjust to handling or habitat changes
- Isolate them from any household stresses like loud noises
With attentive care and minimal disruptions, green anoles typically retain their verdant hues. But intermittent stress-related browning is normal. Just monitor for other health issues if it persists. With some tweaks to their habitat and care routine, your greeny will soon return to their vibrant green glory!
Camouflage Purposes
Blending in With a New Environment
Green anoles have the remarkable ability to change color from green to brown and back again. This color change allows them to easily blend in with their surroundings in order to hide from predators or ambush prey (1).
When a green anole is placed in a new environment with different colored foliage, like a brown tree trunk, it can morph its skin tone to match in just a few hours. This rapid color change is enabled by specialized iridiphores cells in their skin that reflect light to take on the predominant environmental hue (2).
Research has shown that green anoles can perceive color changes in their surroundings and activate the iridiphore cells to transform accordingly (3). For example, an experiment placed green anoles on brown tree bark during both night and day over a two week period.
The lizards shifted almost completely to brown within the first few days to mimic the tree bark, and then partially shifted back to green at night when the brown bark was harder to perceive. This demonstrates how green anoles use color change as an impressive camouflage tactic toblend into new environments.
Hiding From Predators
A green anole’s ability to shift skin color not only helps it match new scenery, but also enables effective hiding from predators. By turning brown, green anoles can avoid detection from predatory birds that hunt by sight when climbing on tree trunks and branches (4).
Their change in coloration makes them practically invisible. Research tracking bird predation on brown anoles versus green ones in their natural habitat found that the brown lizards survived attacks an average of 63% more often (5).
This underlines how much of a survival advantage camouflage provides.
In addition to birds, green anoles live under constant threat from other reptile predators like snakes. Again, their camouflage abilities prove vital for evading detection. Scientists set up an experiment placing green anoles on brown cardboard strips within test enclosures that either contained snakes or did not.
The lizards shifted to brown rapidly when snakes were present nearby as an instinctual defensive reaction (6). By changing color to match the background, green anoles can effectively hide from predators and greatly improve their chances of survival.
Sickness or Health Issues
There are a few potential health issues that can cause a green anole to turn brown. Here are some of the main causes:
Stress
Stress is a major factor that can lead to color changes in green anoles. Sources of stress include:
- Improper housing conditions – Lack of hiding spots, incorrect temperatures/humidity, overcrowding, etc.
- Habitat disturbances – loud noises, predators, too much handling by humans
- Illness or injury
- Poor nutrition
When a green anole experiences chronic stress, its body reacts by releasing more corticosterone hormones. High corticosterone levels interfere with color pigment production, causing the green pigments to fade and more brown/grey tones to appear.
Brumation
Brumation refers to a hibernation-like state that reptiles enter during cold winter months or seasons of drought. Green anoles typically brumate from late fall through early spring when temperatures drop and food/water sources decline.
During brumation, a green anole’s metabolism will slow down significantly. Lethargy sets in, activity decreases, and appetites fade. With limited energy to produce color pigments, green anoles will turn varying shades of brown/grey until spring returns.
Shedding Complications
As green anoles outgrow their skin, they shed the outer layer in a process called ecdysis. Shedding difficulties can arise if the humidity level is too low.
Problematic sheds — where unshed skin remains stuck — can restrict blood flow, cause dehydration and skin infections. The lack of blood/nutrient flow to skin cells will also result in color fading to brownish tones.
Parasites
Mite infestations are the most common external parasite issue in pet green anoles. When mites attach themselves to the lizard and feed on its tissue/blood, this can cause significant irritation, open wounds, decreased immune function, and high stress.
Internal parasites like roundworms, hookworms, coccidia and flagellates can also lead to nutrient deficiencies, cellular damage, secondary infections, and chronic stress — all reasons for green color loss.
Kidney/Liver Dysfunction
Since color pigments are produced at a cellular level, any issues with major bodily processes can interfere with coloration. Two key organs — the kidney and liver — are largely responsible for filtering toxins from the bloodstream.
If these organs become damaged and cannot properly remove waste products, toxins will build up and start destroying healthy cells. With cells struggling to function, the intricate process of producing green pigment proteins gets disrupted.
Shedding the Skin
Shedding the skin is a natural process for green anoles. As reptiles, anoles continuously grow and need to periodically shed their outer layer of skin to accommodate this growth. This process is called ecdysis or molting. Here’s a more in-depth look at why and how green anoles shed their skin:
Why Do Anoles Shed Their Skin?
Anoles shed their skin because their bodies are constantly generating new skin cells underneath the outer layer. As new skin develops, the older outer skin becomes tight and restrictive. Shedding allows the old skin to slough off so the new skin is exposed.
There are a few key reasons anoles need to routinely shed their skin:
- To accommodate growth – Young, juvenile anoles are growing rapidly and shedding often to allow their body size to increase.
- To remove damaged tissue – Shedding gets rid of old, worn skin that may have received minor abrasions or other damage.
- To avoid parasites – Shedding can help eliminate some external parasites like mites that may be present on the skin.
- To change color – Green anoles can sometimes take on browner hues when about to shed, as the process of new skin generation begins.
How Often Do Anoles Shed?
The shedding frequency depends on the anole’s age:
- Baby anoles – May shed every 4-7 days as they are growing rapidly.
- Juvenile anoles – Will shed about every 10-14 days.
- Adult anoles – Only need to shed every few weeks or months once full size is reached.
Factors like diet, environment, and health can also impact shedding frequency. For example, anoles that are well-fed on nutritious insects may shed more often than undernourished lizards.
What Happens During the Shedding Process?
Anoles go through visible physical changes when they are about to shed. Here is an overview of the shedding stages:
- Dull coloration – Their normally vibrant green color will become darker or brownish, often starting 1-2 days before the shed.
- Cloudy eyes – Their eye caps (spectacles) will take on a bluish-white, opaque appearance.
- Change in appetite – They often eat less right before a shed.
- Hiding more – Anoles will seek shelter to begin the shedding process.
- Rubbing against surfaces – Helps loosen and separate the old outer skin.
- Eating the skin – Anoles often consume the shed skin to recoup nutrients.
Once the old skin is completely removed, the anole will become bright green again within a day or two. Its eyes return to normal clarity as well. The whole process takes around 1-2 days from start to finish.
Signs of a Healthy Shed
To ensure your anole is shedding properly, look for these signs of a healthy molt:
- Sheds in one intact piece, including clear eye caps.
- No unshed skin remaining on toes, tail, or body.
- Eats normally shortly after shedding.
- Bright, vivid coloration returns.
- No injuries, bites, or wounds from rubbing.
Trouble shedding can be a symptom of dehydration, poor nutrition, or health issues. Schedule a vet visit if your anole has frequent difficulty with stuck sheds.
Through proper anole care and habitat setup, most green anoles will shed easily every couple of weeks without issues. Pay attention to their shedding schedule and look for any changes that could indicate a problem.
Conclusion
While a brown anole may seem concerning at first, in most cases it’s a normal part of your lizard’s biology. By understanding what triggers this color change, you can ensure your green anole stays happy and healthy.
Monitor for other signs of stress or illness if the browning persists. With proper habitat conditions, nutrition, and low stress levels your anole should regain its bright green hues.
