Some species of birds like ptarmigans change color every spring giving up their white winter feathers and growing a brown summer plumage. Since feathers cannot heal themselves when damaged, they have to be completely replaced. The replacement of all or part of the feathers is called a molt. Some birds molt again in fall. In contrast to such slow color changes, chameleons and a number of other animals do quick change of colors.
The pigment cells in the skin are the agents of change. An animal taking on the color of its background is not making a conscious decision. The color change is built-in, reflex action over which the animal has no voluntary control.
By expanding and contracting its color cells, certain species of fish (especially flounders) can vary the amount of pigment that shows on the skin. They can imitate a light sandy bottom; a dark, muddy bottom. Octopuses, squids, chameleons, certain lizards, shrimps and crabs also have the ability to change color rapidly. Most of them however change color when they experience emotions like anger and fear. Frogs and toads change color not only with mood but with temperature and humidity. Occasionally they also attempt to change color to match their backgrounds.
attemptNwin.com, the complete site for children.
Bring out the leader in children by making them inquire, innovate and be creative.
Click for more articles.