Color Change in Animals
The color of an animal depends on the light that is reflected from its skin, fur, or feathers. Most animals are pretty much stuck with the color they have; however, some animals exhibit dramatic seasonal variations in color, while others have the ability to change color on the fly.
Many animals found in the far north undergo significant changes in the color of their fur or feathers to blend in with their surroundings during the winter. Animals like the snowshoe hare, arctic fox, weasels, and ptarmigan undergo a brownish phase during the growing season then they shed or molt their fur or feathers, and develop a white coloration during the winter. Blending in with the snow helps these creatures avoid predators while obtaining food to survive during the harsh winter months. Since hair and feathers are dead tissue, these animals must shed their old fur or molt their feathers to develop their winter coat.
There are a number of other animals that have multiple layers of skin that contain structures called “chromatophores,” which consist of distinct pigments that they can engage to change colors quickly. One of the most famous of these animals is the chameleon. The word “chameleon” loosely means “lion of the ground” in Greek; these smallish reptiles are some of the best hunters in the reptile world. Chameleons are mostly insectivorous, with long tongues that can lash out and grab insects even when the unsuspecting prey is in flight. Chameleons are found in warm climates in southern Europe, Africa, and Asia. They have become naturalized in parts of Florida and California, as well. Most species of chameleon have a clear outer layer of skin and at least four layers of skin below that contain yellow, red, blue, and brown pigments. The color that the chameleon projects at any given moment is due to the combinations of chromatophores that are activated. Up until recently, it was thought that chameleons change color in response to their surroundings, but it is now believed that color changes are in response to the mood of the individual or some external signal like the amount of daylight, or temperature. A chameleon changes color in response to hormones in the blood, or impulses in the nervous system. Depending on the location, a relaxed chameleon would be green, brown, or gray. Chameleons found in the dessert are darker during the evening and early morning turning lighter during the day in response to temperatures and sunlight. It is believed that these color changes help the chameleon regulate heat and camouflage themselves from predators. Chameleons in lush environments can show dramatic color changes with various shades of green, yellow, orange, red, brown, blue, or purple in response to the chromatophores that are activated. The relaxed chameleon in a lush setting is usually green. Chameleons also change color in response to various moods such as anger and fear, and to various activities such as stalking prey, or trying to impress a potential mate. Besides chameleons, other animals that display various colors include flounders, seahorses, some snails, octopus, and squids.
Article by FCFCDB member
Nature note for 2/9/20