Majestic giants of the African savanna, giraffes' unusual bodies are similar across their nine subspecies. Their long necks, which are often used as an example of the effects of natural selection, enable them to graze higher than most other animals, but they have several other body parts that are also special and interesting, such as their tongues, eyes and horns. Giraffes' unusual -- and in some cases unique -- features reveal aspects of their lives and behavior.
Giraffe necks are their most noticeable feature. Despite their length, they contain only seven vertebrae, the same as humans, but each one can be more than 10 inches long. Giraffe legs are even longer than their necks, so that when they bend down to drink they must spread their forelegs wide or bend them to reach the water. Their neck veins contain a series of valves to prevent blood flooding their brains when they lower their heads. Male giraffes use their long necks when fighting, swinging their heads to club their opponents.
Giraffe tongues are essential to enable them to graze. They eat acacia tree foliage, which is well-protected with sharp thorns. Giraffes' 18- to 20-inch tongues can grip and sort the succulent leaves from the thorns. Their tongues are also tough-skinned and their mouths produce thick saliva which may help protect them from injury. The roofs of their mouths are grooved, enabling them to strip leaves from trees. The front half of their tongues, which are exposed while eating, is dark blue, purple or black, which may help protect from sunburn.
Protection from predators and harsh weather conditions are important for giraffe survival. Their large, bulging eyes are set on each side of their heads and held high above the ground, which gives them a nearly 360 degree field of vision. Their long, fine eyelashes protect their eyes from hot, sandy wind and can also keep out ants and sense thorns on branches as they feed, preventing damage to their eyes. Giraffes have the largest eyes of all land mammals.
Giraffe horns, called ossicones, are unique among mammals. At birth, all giraffes have knobs of cartilage on their skulls, covered by skin and hair. As the animals grow, their horns grow larger and turn into bone. Used for fighting, male horns grow thickest and add weight to their heads when butting other males. The hair on top is often worn away by sparring contests. Older males in some subspecies grow a second pair behind the first.
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