Of course, the giraffe didn't evolve its long neck from stretching its neck muscles and passing on that trait to its offspring as the standard biology text refutation of Lamarckism points out. And it really isn't "silent." But there are some rather interesting and remarkable things about this "camel with leopard's spots."
The giraffe is a member of the Order Artiodactyla ("even-toed") and the Suborder Ruminantia. It is the tallest ruminant animal (and mammal, for that matter) and like the similarly ordered/subordered cow, it has a four-chambered stomach that allows digestion of its cellulose-rich diet. Its Family is Giraffidae (deriving from a word meaning "one who walks swiftly") which only includes two animals, the giraffe and the okapi.
The scientific name for the giraffe is Giraffa camelopardalis. The second part of the name meaning "a camel marked like a leopard" or, more simply, "spotted camel." That was the word used by the Romans to describe the animal. The word "camelopard" survived in English as a referent to the giraffe, though is rarely used today.
While the giraffe is the only species in its genus, there are at least nine subspecies (depending on the reference), designated by geographical location and spot patterns (which are unique like fingerprints). These are:
Angolan (G.c. angolensis)
Kordofan (G.c. antiquorum)
Masai (G.c. tippelskirchi)
Nigerian (G.c. peralta)
reticulated (G.c. reticulata)
Rothschild (G.c. rothschildi)
Thornicroft (G.c. thornicrofti)
South African or Cape (G.c. giraffa)
Where to spot a Camelopard, what it will be eating
Giraffes are found primarily in sub-Saharan east Africa on the savannas and open bush country. There are some populations more to the West and some more to the South. It tends to live in areas with a sufficient amount of trees, preferring Acacia and Combretum. While it seems to prefer the two types of tree, the giraffe has been known to eat over a hundred species of plants. Leaves and shoots, mostly, but also flowers, vines, herbs, even bird nestssometimes with young insideand has been seen chewing on bones (it is thought this might be to gain minerals). The giraffe can spend sixteen to twenty hours a day feeding and can eat over 34 kg (75 lb.) each day.
male: 4.6 to 5.5 m (15 to 18 feet)
female: 4 to 4.8 m (13 to 16 feet)
male: 800 to 1930 kg (1765 to 4255 lb.)
female: 550 to 1180 kg (1215 to 2600 lb.)
As can be seen, there is sexual dimorphism in the species, favoring the male. The horns on a female also tend to be smaller. Additionally, the reticulated subspecies tends to be smaller than others.
The giraffe is tall and lanky, topped with two to four horns (covered with skinreally bony masses and not true horns). Its face is long and narrow and its ears stick out to the side. It has long eyelashes that are helpful in foraging for food, as the trees it often feeds from can be home to colonies of ants and often have thorns. They function to keep both away from the animal's eyes. It has a short body, in comparison to its height, with its long neck and legs, that slopes somewhat from the shoulders back. The patterns are reddish or brown "spots" ("polygons," in one source) over a buff background which darken with age. The coloration functions as camouflage, mimicking the shadows and sunlight through the leaves of a tree.
Because the spots are more prominent so that the lighter color appears to be lines of a net over them, the subspecies G.c. reticulata was so namedderiving from the Latin reticulum, meaning "network." It also has a small mane and long tail with a bushy end.
Camelopards by the throat
The giraffe's most obvious feature is, of course, its neck. Despite its great length (up to 2.44 m or 8 feet), the giraffe has the same number of neck vertebrae as do almost all mammals (7). This adaptation allows it to reach parts of trees unavailable to other animals (with the exception of an elephant) so that competition for food is limited.
Even though it might appear unable to (or only with difficulty), the giraffe can bend over to eat or drink. On the other hand, most water is taken in from the vegetation in the diet (also from dew on the leaves) and the animal only drinks every two to three days (it can go over a week without drinking). When it does find a watering hole, it can drink up to 45.42 L (12 gallons) at one time.
This long neck and the height of the animal bring about some of its most amazing physical adaptations. Given the difference in height from standing upright and bending over to the groundmaking the heart pump the blood about 2.5 m (8.2 feet) either way to the brainone might expect that standing would cause a loss of pressure resulting in passing out and bending an increase that in one source described as would make the "brain explode" (i know, i know). How does the giraffe escape these potential problems?
It starts with one of the biggest hearts in the animal kingdom. It can weigh as much as 12 kg (26.45 lb.) and pumps as much as 61 l (16.11 gallons) of blood per minute and has pressure twice that of humans. It beats around 170 times per minute. Giraffes in captivity have hearts less than half the size due to less exercise and need for running, something the giraffe is quite good at, able to reach speeds up to 48.28 km per hour (30 mph) or more.
In addition to the heart, it has a special circulatory system that allows it to escape either fate. Just before the carotid arteries reach the brain, they divide into a network of many smaller vessels. These vessels have elastic walls and can hold excess blood if needed, to avoid too much rushing to the head, causing the "explosion." This also aids the animal when it is standing so that the blood can be retained, avoiding too little flow to the brain. There are also a connection between the carotid and the vertebral artery that allows excess blood to drain off if necessary. The majority of the veins near the skin surface coincide with the light "net" pattern. This is thought to help in maintaining body temperature.
Less obvious, but still fascinating, adaptations can be found to aid feeding. The pink and black tongue of a giraffe can be 45.7 to 55.9 cm (18 to 22 inches) long. It is prehensile and allows to (with the aid of its upper lip) strip the leaves from the trees on which it feeds. It also has a thick saliva and specially designed palate (which is also grooved, helping to strip the leaves) to deal with the thorns found on the trees.
They have exceptional eyesight (as well as smell and hearing) and the largest eyes of any land mammal. Other savanna-dwelling creatures (such as antelope, ostriches, and zebras) have been known to use giraffes as a means to be alerted about predators. Adults are not often subject to predation except from humans (one reason being giraffe hair bracelets, but also for meat and hides) but the young are at riskit is estimated that as many as 50 to 75 percent of calves are killed within the first few months. Particularly dangerous to them are lions (of course), hyenas, leopards (ironically), and wild dogs.
Not that there is no way to protect them. A parent will stand over a calf and fight even a lion, using its strong (recall the speeds it can reach) forelegs to viciously kick at the threat. Males will spar among themselves by swinging their necks at each other and butting heads as a way to establish dominance for mating purposes and the best feeding areas (they have thicker bone in their skulls for protection against injury). This is not used as a protective measure, however, and once a male has established his choice, they live together without conflict.
Camelopard society and where babies come from
Giraffes live in moderately sized herds of twelve to fifteen (though much larger ones, up to a hundred, have been observed) but the social structure is weak. In groups of twenty there is no leader as with many social groups. Their size makes it unnecessary to remain in a small group and they can spread out over 1.6 km (1 mile). Territory can be a large as 119.13 square km (46 square miles). Since they are so tall and can see each other over long distances, these arrangements are possible.
Giraffes reach sexual maturity at about three or four years of age, though males generally do not have the chance to breed for six to eight years because of the mating pecking order of older bulls. Females (cows) usually conceive in their fifth year. Breeding can take place year round but is more common during the rainy season. There is a long gestation of fourteen to fifteen months with a single calf born. Because of the mother's height, the calf actually drops 1.8 m (6 feet) to the ground when born.
At birth, the calf is already 47 to 70 kg (103 to 154 lb.) and 1.8 to 1.9 m (6 to 6.33 feet) tall. They grow quite fast and can walk within an hour of birth and run within a day. By age one, the calf will be about 3 m (9.84 feet) tall. They begin eating plants a few weeks after being born, though suckling may last up to a year. At about a year and a half, offspring will leave the protection of the mother. The life expectancy is ten to fifteen years in the wild and around twenty-five in captivity.
Nonsilent majority: talking Camelopards and another myth dispelled
The prevailing wisdom is that giraffes make no vocalizations. As is usually the case, the prevailing wisdom is wrong. It is true that they do not make sounds often, but they can be quite talkative when they choose. In the words of one source, they can "grunt, snort, growl, sneeze, snore, moo, bleat, and cough" (yeah, moo). Quite a repertoire for a supposedly mute mammal.
Another belief is that, because of their physical attributes, they never lie down. Another myth. The giraffe can, indeed, lie down. They will lie down to sleep for short periods of one to twenty minutes (granted, the brevity is probably due to the physical limitations of the animal). The giraffe will lie on its side with its neck and head across its flank. Also, during the first couple weeks after birth, the mother will often lie on her side, guarding the young.
A (very) Brief History of Camelopards
Awareness and appreciation of the giraffe goes back thousands of years. African cave paintings have been found that feature them (very likely as a food source) and the ancient Egyptians made jewelry with giraffe designs. Sandals and shields were make of its hide and some tribes supposedly treated nosebleeds with smoke from burning skin.
While a protected species, poaching does go on and as populations expand (especially agricultural), they are coming into conflict with man. In the years to come, territory is likely to continue to decrease and the possibility of giraffes being killed for damaging crops and competing with domestic herds will increase.
(Sources: www.zoo.org/educate/fact_sheets/savanna/giraffe.htm, www.oaklandzoo.org/atoz/azgiraf.html, www.thebigzoo.com/Animals/Reticulated_Giraffe.asp, www.chaffeezoo.org/zoo/animals/giraffeheart.html, www.seaworld.org/AnimalBytes/giraffeab.html, animaldiversity.ummz.umich.edu/accounts/giraffa/g._camelopardalis$narrative.html, www.britannica.com, 184.108.40.206/curator/WebOfLife/Kingdom/P_Chordata/ClassMammalia/ClassMammalia/OrderArtiodactyls/giraffe.htm;
the www.thebigzoo.com page turns your cursor into a giraffevery coolI took the quiz there and am now "certified" as a "Reticulated Giraffe Expert," so there....)