Struthio camelus massaicus
Ostrich males can be up to 8 feet tall. Females are somewhat shorter. They may weigh up to 160 pounds. The ostrich is the largest living bird, and also the heaviest. The head is small in relation to the size of the bird, but its huge eyes, protected by long, black eyelashes, are the largest of any terrestrial vertebrate, with a diameter of 2 inches. The feathers are unusual in that the barbs are loose, due to the absence of hooks on the barbules, and the plumage is soft and smooth. They are unable to water-proof their feathers, which tend to become sodden in rain. There are only two toes, the inner of which is thick and strong. This is an adaptation for running, and helps make the ostrich the fastest runner in the bird world. It also has great stamina, and can keep up a speed of 31 miles per hour for over 30 minutes. They use the wings for balance at high speeds. The male is mostly black, but the wings and tail are nearly pure white. The female is much more drab. Her body feathers are brown with pale fringes, with the wings and tail a dirty white. Juvenile plumage is similar to the female’s. During the breeding season the pink of the male’s neck becomes much brighter.