Credits: “Awake 1981 edition” correspondent in Nigeria
“WE WERE on safari in Kenya. Our eyes were darting everywhere, missing nothing. Or so we thought, until, suddenly, Runé held my arm and said, ‘James has seen something!’
“James, our Kenyan guide, was pointing to a sausage tree 400 feet (120 m) away. ‘There’s a leopard,’ he said.
“‘Where?’ asked Sören.
“I looked, changed the angle of my vision, rubbed my eyes and looked again. I saw nothing but leaves, branches and the sausage-shaped fruits.
“James chuckled. ‘Let’s go closer,’ he said. We approached to about 50 feet (15 m) from the tree and then I saw it. Spots and blotches, white and brown, now showed up in the solid shape of the leopard, distinct from similar spots and blotches and colors of the tree and sunlight.
“James said he might not have seen the leopard if the tail had not been hanging down with a curl at the end. The curl was an unusual shape in the tree, so he looked again and saw the animal.” Thus Gösta and his friends became aware of the impressive world of animal camouflage—a world that is evident all around us in the resemblance that animals have to their surroundings. Quite naturally, they, like most of us, desire to know how the camouflage works and who or what is to be given credit for this ability that animals have.
How the Camouflage Works
Camouflage in animals is essential for their survival. It serves as a means of concealment from predators, or helps the predators to remain inconspicuous while stalking, waylaying or baiting their prey. The principle is the achieving of invisibility by confusing the vision of other creatures.
Gösta’s experience with the leopard illustrates this. Like many other creatures, leopards have the mottled appearance of a forest that has sunlight filtering through the trees. They also have the ability to remain motionless and become invisible by merging with their surroundings.
This is true even of the zebra, which may seem to be the most obvious of wild creatures. The zebra’s stripes serve the same purpose as the leopard’s mottled coat. The pattern of contrasting shades and forms seems to break up the shape of the animal into irregular patches or stripes. This is because, when looking from a distance, the eye finds it difficult to fit a broken color scheme together into one solid form. It responds to the illusion created by the disruptive coloring and sees the pale background of the animal’s coat as the light spaces between trees and grass.
So the zebra merges with the slender tree trunks and stalks of grass, and the leopard “disappears” into a tree or bush. One marsh-dwelling bird, the bittern, also merges with the reeds in its habitat because of its striped russet and black coloring. But it increases its camouflage by standing immobile among the reeds with its neck and bill pointed straight up, whenever danger threatens. It even sways with the windblown reeds.
In addition, there is the countershading pattern in which the coloration of the upper parts of animals is darker than the undersides. This counteracts the effect of sunlight, which accentuates the three-dimensional appearance of an object by casting a shadow on its lower surface and on the ground. Because of the countershading, the shadow cast by the animal’s upper portion darkens the paler underside and, to all appearances, reduces its form.
By contrast, other creatures merge with the background because of color resemblance. The white polar bears, the green parakeets and grasshoppers, as well as the black, gray or dusky nocturnal creatures all resemble the color of their environment. This is also true of the delicate or gaudy colors of insects, frogs, lizards and birds that spend their lives among flowers and leaves.