Many animals depend on camouflage to either hunt their prey or even hide from their predators for example, many types of frogs, butterflies, and owls are a small portion of the total number of animals that use camouflage. They most likely have evolved over time to help increase survival and reproduction rates. It’s interesting to see how their camouflage works, but I am focused on one animal in particular, the Chameleon. The chameleon is a special case because instead of having one color, their body changes color based on something else. Now that I mention that, do you wonder why they do and how?
After doing some research, chameleons skin color change is in fact not for camouflage, but to regulate their body temperature and to communicate with others. Mary Bates, author of the article How Do Chameleons Change Color? explains that chameleons actually can’t generate their own body heat. Changing their skin to a dark color allows the chameleon to warm up by absorbing the sun’s heat and with the opposite they can change to a light color to simply reflect the light to cool off. In addition to heat change, male chameleons can change their color to a dark bold color to show they are aggressive or to a bright color to assert their dominance.
So how does this actually happen? In the same article, Mary Bates writes that the outer layer of skin on the chameleon is transparent plus they have multiple layers of skin like humans. Beneath those layers are special cells called chromatophores. At each level of skin, these chromatophores contain small sacs of different kinds of pigments, which is basically the coloring matter for the animal’s skin. Now at the deepest level of skin, there are melanophores, which are star shaped cells that extend towards the surface of the skin. These melanophores are filled with brown melanin, similar to humans. Mary Bates says that on top of the skin are different types of cells correlating to different colors. For example, on the skin of the chameleon, there are cells called iridophores which reflects blue and white lights. In addition, other cells like xanthophores and erythrophores contain pigments like red and yellow which are then reflected off of the chameleon’s skin.
Now to change its color, the chameleon’s nervous system would take over and based on the chameleon’s behavior, certain chromatophores would begin to expand or contract allowing the change of color you would see in its skin. Overall, chameleons are not the only animal where this color change happens, in fact it happens to many others for similar reasons.