Why Frogs Change Color: Survival of the Fittest
Thanks to fairytales and children’s stories, a frog had been pictured for years as a slimy green creature with a long tongue that catches flies. Though frogs are really slimy and they really have long tongues that catch insects, most of the frog populace is not actually green. It is not often realized that natural colors, such as green is merely an easy way to blend in with the natural habitat of these slimy creatures.
Unlike humans whose melanin in skin cells is more or less fixed, frogs have the ability to camouflage themselves. Also, human change in skin color is triggered by an outer factor, usually sunlight. Frogs, however change their color at their own will as their mood or surroundings change as well.
Basically, frogs have three types of pigmentation or chromatophores. One is the melanophore (brown pigment), iridophore (highly reflective pigment), and xanthophores (yellow pigment). When needed, frogs could put these pigments into use. They could produce a wide variety of shades from brown to grey, and of course, green. In rare species, strong iridophore produces red and blue just the same. These chromatophores are controlled by the frog’s central nervous system and hormones.
That now answers how frogs change color. Knowing that is essential to finding out why exactly frogs camouflage. It has to be remembered first where frogs live. If it’s just like some old children’s story, the frogs would be comfortably living in the city. They would be bathing in marble bath tubs and climbing the Big Ben. But truth be told, frogs are far from that.
Frogs live in swamps, forests, and other places. These places are filled with the prey they need as food to live. More notably, these places are drowning in predators which need frogs as food to live.
There are some blessed ones as the blue Poison Arrow frog. The Poison Arrow need not blend in with its surrounding for its skin is covered with poisonous slime. Whatever touches the blue frog gets poisoned quickly enough for the naturally-gifted amphibian to escape its apparent end.
But since not all frogs are as blessed, they require a different approach of avoidance. Some frogs change their color to blend in to their surrounding. Being virtually invisible makes them avoid their predator. Some frogs take their color change to the next level.
Tropical colors like reds, oranges and blues that are so bright they could be seen from afar, signal to predators that they shouldn’t be eaten. Apparently, colors mark them as poisonous and inedible. So instead of avoiding predators through blending with the background, some frogs turn into reds or blues and oranges. That way, the predators no longer seek them, but avoid them.
This strategy of deception is more effective. The earlier approach, blending with the surroundings, is effective as well but it relies too much on invisibility. Some predators are talented and skilled enough to find camouflaged preys in time. The latter approach relies on scaring the predator—way more effective, even in non-tropical areas.
But as mentioned earlier, some frogs don’t have enough iridophores or reflective pigments to utilize so they could turn into tropical shades. With this, others use the surprise element in their attempt to flee or avoid their death traps.
Some frogs could only change their bottom half into a tropical color as the rest remain a subtle brown or grey with the rest of their body. When a predator approaches, the said frog turns over and exposes its “poisonous area.”
With that, two situations usually occur. One, the predator runs away or leaves in fear of its own life. Two, the predator is too taken aback and needs some ample time to think. It needs so much time to recover, the frog gets a chance to escape as it once more turns upright—blending in with the color of its surroundings.
There will always be tragic endings where changing colors would not be enough to deceive the predator. But frogs have remained to change their colors through the years, and this proves one thing: their camouflage have generally made them a superb creature that could escape death.
Predators aren’t the only the reasons for frogs to change colors. The other is natural survival. Remembering art class and the color palette, dark colors absorb heat more. Black, brown, gray and dark blues absorb heat more than yellows, oranges and white.
In tropical areas where temperatures tend to change every now and then, frogs change colors to adjust with the heat. In desert areas, frogs tend to be bright. In cold swamps, frogs tend to be dark blue or brown. Although there are other factors that come into play, like predator avoidance for example, temperature is a huge reason why frogs change color too.
Also, color change happens within a day. If its hot in the middle of the day, frogs turn ivory white or bright yellow to ward off heat. But when the rain suddenly comes or when the cool breeze of the night arrives, frogs turn a darker shade of brown or gray.
At the end of the day, one word packages the reason why frogs change color. It’s not leisure or mood swings or even hormones. It’s all about one word: survival.