Have you ever noticed that many of our backyard birds including juncos, titmice, mockingbirds, and a whole host of others are dark on top and a lighter shade on the underside? This contrast is known as “countershading.” The coloring can vary from shades of brown, gray, and black above with buff, light gray, and white below.
In nature, everything has a purpose and the purpose of countershading has to do with concealing the bird from predators. In the case of the Slate-colored Junco, for instance, the two-tone countershading breaks up the outline of the bird’s body as a sort of camouflage to help it blend into its surroundings. The top half of the junco is dark so when seen from above (perhaps by a hungry hawk), it blends in with the darker ground; when seen from below, the bird’s white belly blends in with the lighter coloring of the sky.
Even when viewed from the side, the two-tone coloring of the Tufted Titmouse disrupts the bird’s outline, helping to conceal it from predators.
Many hawks including the Red-tailed Hawk receive benefit from countershading. Although hawks are at the top of the food chain and so have few natural predators, other predatory birds, such as bigger hawks and eagles, will steal a kill from the Red-tail if they get a chance. Just as countershading helps conceal smaller birds from predators, it helps the Red-tail escape detection by competitors while he finishes his meal.
It’s interesting to look at the physical characteristics of birds not just from the standpoint of beauty, but from the perspective of how these traits help them to survive. When we understand that a bird’s coloring can help to attract a mate or avoid detection by a predator, it becomes clear that beauty is indeed as beauty does.
Nature is man’s teacher. She unfolds her treasures to his search, unseals his eye, illumes his mind, and purifies his heart; an influence breathes from all the sights and sounds of her existence.” ~ Alfred Billings Street.