Chameleons are well known for their ability to change color and blend into their surroundings. This color changing ability is one of the characteristics that make chameleons unique among lizards. But do chameleons really use their color changing ability to camouflage themselves from predators and prey? Keep reading to learn more about chameleons and their amazing color changing abilities.
An Overview of Chameleons
Chameleons belong to the family Chamaeleonidae, which includes over 200 species. They are found throughout Africa, southern Europe, and southern Asia. Chameleons are arboreal lizards, meaning they live in trees and bushes. They have several specialized adaptations that allow them to thrive in treetop habitats, including:
– Grasping hands and feet – Their toes are grouped into opposing bundles of 2 and 3 toes that allow them to firmly grasp branches.
– Prehensile tail – The tail can wrap around branches to give added support.
– Independently movable eyes – Their eyes can rotate and focus separately to allow for depth perception and scanning a wide visual field for prey and predators.
– Sticky tongue – The tongue can rapidly extend over twice the length of their body to catch prey. The end is a suction cup that adheres to prey.
The Color Changing Ability of Chameleons
The characteristic most associated with chameleons is their ability to change color. But how does this work exactly?
Chameleons can change their color and pattern by adjusting different layers of specialized skin cells called chromatophores. There are several types of chromatophores:
– **Melanophores:** Contain black and brown pigments
– **Xanthophores:** Contain yellow to red pigments
– **Iridophores:** Reflective pigments that create blue, green,yellow or reddish iridescent colors
– **Leucophores:** Reflective tissue that creates white colors
By adjusting the spacing and size of the chromatophores, chameleons can quickly change both the color and patterns displayed on their skin.
Functions of Color Change in Chameleons
The primary functions of chameleon color change include:
– **Camouflage** – Blending in with surroundings to avoid predators and conceal themselves from prey
– **Communication** – Bright displays to attract mates, threaten rivals, or warn predators
– **Thermoregulation** – Dark colors absorb heat, light colors reflect heat
– **Expression of Mood/Health** – Darker when cold, stressed or sick. Brighter when warm and healthy.
Do Chameleons Change Color for Camouflage?
Now to the main question – is camouflage really the primary reason chameleons change color? Research suggests camouflage is one reason for color change, but not the only or even primary reason.
Some key points:
– Chameleons do often show color and pattern changes that match their surroundings, providing camouflage from predators and prey. However, the changes are relatively slow, taking minutes to hours. This makes it ineffective against fast moving predators.
– Color change is complex and serves multiple functions beyond camouflage, including thermoregulation, communication, and expression of health/mood.
– Chameleons are very visually oriented and use excellent eyesight combined with slow, deliberate movements to hunt prey and watch for predators. Crypsis through camouflage is likely just one survival strategy.
– Chameleons change colors when alarmed or stressed even without any changes in their surroundings. This suggests color change is not simply a reflexive response to match backgrounds.
Scientific Studies on Chameleons and Camouflage
Controlled scientific studies have tested the camouflage color changing abilities of chameleons:
| Study | Methods | Results |
|---|---|---|
| Stuart-Fox et al. 2006 | Tested color change in veiled chameleons on different colored backgrounds over 20 minute periods. | Some color change ability demonstrated but not precise or complete background matching. |
| Stuart-Fox et al. 2008 | Tested veiled chameleons on patterned vs. plain backgrounds over 90 minute periods. | Better background matching demonstrated on plain backgrounds compared to patterned. |
| Tolley et al. 2013 | Tested dwarf chameleons on matching vs. non-matching substrates over several hours. | Some ability to match backgrounds shown, but effective camouflage patterns not maintained at night. |
These studies demonstrate chameleons do have some ability to change their appearance to match backgrounds, lending support to the idea of color change for camouflage. However, the camouflage effect appears incomplete and slow. Total background matching does not seem to be the primary driver of color change.
When Are Chameleons Most Likely to Use Camouflage?
Chameleons likely rely on camouflage in select circumstances when it can provide an advantage:
– When inertia lapses – A motionless chameleon is well camouflaged but once it moves the effect breaks down. After stopping they may need to re-establish camouflaging colors.
– When first spotting a predator – Quick color changes may help conceal position from an approaching predator.
– When ambient temperatures are incompatible with thermoregulation needs – They may sacrifice ideal thermoregulation colors for camouflage.
– At night – Many chameleons exhibit different patterns and colors at night that likely provide better camouflage when resting/sleeping in vegetation.
Conclusion
In conclusion, research shows that chameleons do have some ability to adjust their coloration to match their surroundings and provide camouflage from predators and prey. However, camouflage through color change seems to be just one of several functions of color change, and not necessarily the primary one. Chameleons rely more heavily on stealthy, slow movements and excellent eyesight to evade threats. Their color changing ability is complex and serves functions like communication, thermoregulation and expressing health/mood that likely take priority over camouflage in many circumstances. Chameleons probably utilize camouflage opportunistically when their surroundings provide a chance to conceal themselves from specific threats during activities like resting or hunting. So in summary – yes, chameleons do use color change for camouflage to some degree, but it is not the sole or even primary reason for their amazing color changing abilities.
