Physical Characteristics

Male giraffes, known as bulls, can be 4.8 to 5.5 m (16–18 feet) tall at the horn tips, and weigh up to 1360 kg (1700–4200 lbs.). The largest bull on record was 5.87 m (19.2 ft.) tall and weighed approximately 2000 kg (4,400 lbs.). Females, known as cows, are one to two feet shorter and weigh several hundred pounds less than males.

The giraffes head is relatively small, at least in comparison with the large body size of these animals.
The head has a rather elongated profile, with a long, thin upper lip, which is prehensile and used along with the long (about 18 inches), blue-black (to protect from sunburn), mobile tongue to grasp and tear foliage while the animal is feeding. In Southern Africa, giraffes are partial to all acacias and possess a specially-adapted tongue and lips that appear to be immune to the vicious thorns. The giraffe’s canine teeth are splayed out in two or three lobes to comb the leaves off shoots . Giraffes have large eyes, with very long eyelashes. Their ears are short, but quite mobile, and both hearing and vision are acute.

The giraffe is one of the few ruminants born with horns. They are pressed against the skull at birth and slowly pop up over the first week. Both sexes have horns, although the horns of a female are smaller than the males. The prominent horns are called ossicones and are formed from ossified cartilage and are covered with skin. Males can sometimes have the appearance of up to three horns, these are caused by calcium deposits which form bumps on their skull as they age. These horns grow to be about 5 inches long. Each giraffes is covered with unique patterns of spots, except their underbellies, these spots act as camouflage amongst the trees.

Giraffes have long necks (up to 7 ft.), which possess seven vertebrae (the usual number for a mammal) and allow them to reach the leaves of tall trees. The male giraffe's neck continues to grow after sexual maturity has been reached, whereas the females' neck stops growing when maturity is reached at about 10 years of age. Giraffes also have slightly elongated forelegs that are about 10% longer than their hind legs. Their profile is also influenced by the extreme development of musculature on their shoulders and base of the neck. These large muscles are used to keep the heavy neck erect, and they give the animal a rather hunched appearance, with a steeply sloping back. Giraffes have a rather long tail, which ends in a dark tassel.

Horns

Both sexes have horns, although the horns of a female are smaller. The prominent horns are formed from ossified cartilage and are called ossicones. The appearance of horns is a reliable method of identifying the sex of giraffes, with the females displaying tufts of hair on the top of the horns, where as males' horns tend to be bald on top — an effect of necking in combat. Males sometimes develop calcium deposits which form bumps on their skull as they age, which can give the appearance of up to three further horns

Neck

Giraffes have long necks, which they use to browse the leaves of trees. They possess seven vertebrae in the neck (the usual number for a mammal) that are elongated. The vertebrae are separated by highly flexible joints. The base of the neck has spines which project upward and form a hump over the shoulders. They anchor muscles that hold the neck upright.

Legs and pacing

Giraffes also have slightly elongated forelegs, about 10% longer than their hind legs. The pace of the giraffe is an amble, though when pursued it can run extremely fast. It can not sustain a lengthy chase. Its leg length compels an unusual gait with the left legs moving together followed by right (similar to pacing) at low speed, and the back legs crossing outside the front at high speed. When hunting adult giraffes, lions try to knock the lanky animal off its feet and pull it down. The giraffe defends itself against threats by kicking with great force. A single well-placed kick of an adult giraffe can shatter a lion's skull or break its spine.

In addition to its great height, the giraffe is also one of the heaviest land animals. Exceptionally large males may weigh up to 1,900 kg (about 4,200 lb). Females are smaller, rarely reaching half that weight. Compared to other hoofed mammals the giraffe has a relatively short body, but its legs are disproportionately long. The front legs are marginally longer than the hind legs, a feature that contributes to the animal’s steeply sloping back. Mature giraffes have large hooves about the size of dinner plates.

Giraffes have two gaits—a loping walk and a gallop. When they walk, the animals move both feet on one side of their body in unison, followed by both feet on the other side. When they run, giraffes move the front feet together, then the back feet, swinging the hind feet up and planting them in front of the forefeet. While running, the neck of a giraffe moves backward and forward to keep the animal balanced. Giraffes have a top speed of about 56 km/h (35 mph), but because its legs are so long a galloping giraffe does not appear to be going very fast.

A giraffe’s neck can be over 1.5 m (5 ft) in length, but it contains only seven vertebrae—the same number as in most other mammals, including humans. These vertebrae are enormously elongated and are separated by very flexible joints. At the base of the neck, the thoracic vertebrae have spines that project upward, forming a hump over the shoulders. These bones anchor muscles that hold the neck upright, in the same way that cables hold up a construction crane.

The giraffe’s long neck and immense height help it eat leaves that are beyond the reach of other animals. A giraffe can extend its tongue for as much as 45 cm (18 in), wrapping it around leaves like a grasping hand, and the animal’s canine teeth have deep grooves for stripping foliage from twigs. The tongue and lips of giraffes are covered by hard growths called papillae—a vital adaptation for feeding on trees with vicious thorns. Compared to other mammals, giraffes have an unexceptional sense of smell, but their eyes are large and their vision acute. Combined with their lofty vantage point, this gives the animals a panoramic view of their surroundings.

For giraffes, bending down is an anatomical challenge. To reach ground level—for example, when drinking—a giraffe has to splay its front legs at an angle of almost 45 degrees. A giraffe’s circulatory system is also specially modified, because the high pressure needed to pump blood up to its head could cause brain damage when the head is lowered. To deal with this problem, giraffes have elastic blood vessels that relieve some of the excess pressure. They also have a series of valves in their neck veins that ensure that blood always flows from the head back toward the heart, even when this means going against gravity.

Giraffes have short, dense fur with an intricate pattern of dark patches that range from tannish-yellow to chestnut brown. This coloration helps giraffes blend in among trees and leaves, making them harder for predators to spot. Although no two giraffe skin patterns are exactly the same, some regional patterns are so common and distinct that zoologists have identified a number of giraffe subspecies based on the patterns. One of the most striking of these subspecies is the reticulated giraffe, which has large brown patches separated by thin contrasting lines, making a pattern that looks like broken paving. Another variety, the Masai giraffe, has patches with complex jagged outlines. In all giraffes, the coat color tends to become darker with age. In captivity giraffes have lived into their mid-30s, but their maximum lifespan in the wild is about 25 years.

The heads of both male and female giraffes have a pair of bony horns, permanently covered by skin and ending in a tuft of black hair. The horns of males are larger than those of females, growing up to 25 cm (about 10 in) long. The skulls of males continue to deposit layers of new bone throughout life. As a result, a male giraffe’s head becomes progressively heavier and more angular, with bony lumps that look like extra horns. This characteristic—found in no other mammal—is linked to the fights that male giraffes stage to establish dominance for mating.