The giraffe (Giraffa camelopardalis
) is an African even-toed ungulate mammal, the tallest of all land-living animal species. Males can be 4.8 to 5.5 metres (16 to 18 feet) tall and weigh up to 1,360 kilograms (3,000 pounds). The record-sized bull was 5.87 m (19.2 feet) tall and weighed approximately 2,000 kg (4,400 lbs.). Females are generally slightly shorter and weigh less than the males do.
The giraffe is related to deer and cattle, but is placed in a separate family, the Giraffidae, consisting only of the giraffe and its closest relative, the okapi. Its range extends from Chad to South Africa.
Giraffes can inhabit savannas, grasslands, or open woodlands. They prefer areas enriched with Acacia growth. They often drink, and as a result, they can spend long periods of time in dry, arid areas. When searching for more food they will venture into areas with denser foliage.
The giraffe evolved from a 10-ft tall deerlike animal which roamed Europe and Asia 30-50 million years ago. Fossil records show that early giraffids had shorter necks and were more stout in structure. Some had a leg length 83% that of the modern giraffe. There seems to be no parallel increase in neck length in relation to other body parts. The modern giraffe first appeared 1 million years ago.
Evolution, however, did not prepare the giraffe for the dangers of lightning in the zoos where now many live. Wild giraffes presently range across the dry savannah and semi-desert south of Africa's Sahara--wherever trees grow. That must be a saving grace. In its natural home, the giraffe is not the tallest thing around. Trees are. What's more that region sees few lightning strikes (less than one cloud-to- ground flash per square kilometer per year), says Hugh Christian, Chief Scientist for NASA's satellite lightning detection system, which covers Earth.
In zoos, giraffes are frequently the tallest object, and draw lightning — especially in lands where frequent thunderstorms visit. A game reserve in South Africa is such a spot. Unusually high concentrations of dolomite rock draw 15 lightning strikes a month. In 1996, lightning struck and killed an 18-foot tall giraffe (5.5 m).
Male giraffes are around 16-19 feet (4.5-5.5 metres) tall at the horn tips, and weigh 1700-4200 lb. (770-1900 kg) Females are one to two feet (30-60 cm) shorter and weigh several hundred pounds less than males. Giraffes have spots covering their entire bodies, except their underbellies, with each giraffe having a unique pattern of spots.
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.
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.
Social structure and breeding habits
Female giraffes associate in groups of a dozen or so members, occasionally including a few younger males. Males tend to live in "bachelor" herds, with older males often leading solitary lives. Reproduction is polygamous, with a few older males impregnating all the fertile females in a herd. Male giraffes determine female fertility by tasting the female's urine in order to detect estrus, in a multi-step process known as the flehmen response.
Giraffes will mingle with the other herbivores in the African bush. They are benefical to be around because of their height. A giraffe is tall enough to have a much wide scope of an area and will watch out for predators.
Mating Angolan Giraffes at Chudop waterhole, Etosha, Namibia.Giraffe gestation lasts between 14 and 15 months, after which a single calf is born. The mother gives birth standing up and the embryonic sack usually bursts when the baby falls to the ground. Newborn giraffes are about 1.8 metres
tall. Within a few hours of being born, calves can run around and are
indistinguishable from a week-old calf; however, for the first two weeks, they
spend most of their time lying down, guarded by the mother. The young can fall
prey to lions, leopards, hyenas, and wild dogs. It has been speculated that
their characteristic spotted pattern provides a certain degree of camouflage.
Only 25 to 50% of giraffe calves reach adulthood; the life expectancy is between
20 and 25 years in the wild and 28 years in captivity.
As noted above, males often engage in necking, which has been described as having various functions. One of these is combat. Battles can be fatal, but are more often less severe. The longer the neck, and the heavier the head at the end of the neck, the greater the force a giraffe is able to deliver in a blow. It has also been observed that males that are successful in necking have greater access to estrous females, so the length of the neck may be a product of sexual selection.
After a necking duel, a giraffe can land a powerful blow with his head — occasionally knocking a male opponent to the ground. These fights rarely last more than a few minutes or end in physical harm.
Many animals when kept in captivity, such as in zoos, display abnormal behaviours. Such unnatural behaviours are known as stereotypic behaviours. In particular, giraffes show distinct patterns of stereotypic behaviours when removed from their natural environment. Due to a subconscious response to suckle milk from their mother, something which many human reared giraffes, and other captive animals do not experience, giraffes resort instead to excessive tongue use on inanimate objects.
Due to the obvious social and cultural discomfort associated with the addition of milk delivery devices, animal enclosures are often enriched with other stimulus, such as food and mental distractions (toys, scent markings etc). This operates as a distraction, removing the giraffe’s focus from its instinctual tendencies towards suckling, resulting in tongue lolling and licking of objects in close proximity.
Feeding and Cleaning
The giraffe browses on the twigs of trees, preferring trees of the genus Mimosa; but it appears that it can live without inconvenience on other vegetable food. A giraffe can eat 63 kg (140 lb) of leaves and twigs daily. As ruminants, they first chew their food, swallow for processing and then visibly regurgitate the semi-digested cud up their necks and back into the mouth, in order to chew again. This process is usually repeated several times for each mouthful.
A giraffe will clean off any bugs that appear on its face with its extremely long tongue (about 18 in/45 cm). The tongue is tough on account of the giraffe's diet, which can include thorns from the trees that they eat. In Southern Africa, giraffes feed on all acacias, especially Acacia erioloba, and possess a specially-adapted tongue and lips that are tough enough to withstand, or even ignore, the vicious thorns of this plant.
The giraffe has one of the shortest sleep requirements of any mammal, which is between 10 minutes and two hours in a 24-hour period, averaging 1.9 hours per day. This has led to the myth that giraffes cannot lie down and that if they do so, they will die.
Giraffes are thought to be mute; however, although generally quiet, they have been heard to make various sounds. Courting males will emit loud coughs. Females will call their young by whistling or bellowing. Calves will bleat, moo, or make mewing sounds. In addition, giraffes will grunt, snort, hiss, or make strange flute-like sounds. Recent research has shown evidence that the animal communicates at an infrasound level.
Giraffes are hunted for their hides, hair, and meat. In addition, habitat destruction also hurts the giraffe. In the Sahel trees are cut down for firewood and to make way for livestock. Normally, giraffes are able to cope with livestock since they feed in the trees above their heads. The giraffe population is increasingly shrinking in West Africa. However, the populations in eastern and southern Africa are stable and, due to the popularity of privately-owned game ranches and sanctuaries (i.e. Bour-Algi Giraffe Sanctuary), are expanding. The giraffe is a protected species in most of its range.
The total African giraffe population has been estimated to be at least 110,000 up to about 150,000, of which Kenya (45,000), Tanzania (30,000), and Botswana (12,000), have the most.