Giraffes презентация

Giraffe

The giraffe is an African artiodactyl mammal, the tallest living terrestrial animal and the largest ruminant. It is traditionally considered to be one species, Giraffa camelopardalis, with nine subspecies. However, the existence of up to nine extant giraffe species has been described, based upon research into the mitochondrial and nuclear DNA, as well as morphological measurements of Giraffa. Seven other species are extinct, prehistoric species known from fossils.
The giraffe's chief distinguishing characteristics are its extremely long neck and legs, its horn-like ossicones, and its distinctive coat patterns. It is classified under the family Giraffidae, along with its closest extant relative, the okapi. Its scattered range extends from Chad in the north to South Africa in the south, and from Niger in the west to Somalia in the east. Giraffes usually inhabit savannahs and woodlands. Their food source is leaves, fruits and flowers of woody plants, primarily acacia species, which they browse at heights most other herbivores cannot reach.
Giraffes may be preyed on by lions, leopards, spotted hyenas and African wild dogs. Giraffes live in herds of related females and their offspring, or bachelor herds of unrelated adult males, but are gregarious and may gather in large aggregations. Males establish social hierarchies through "necking", which are combat bouts where the neck is used as a weapon. Dominant males gain mating access to females, which bear the sole responsibility for raising the young.

Fully grown giraffes stand 4.3–5.7 m tall, with males taller than females. The average weight is 1,192 kg for an adult male and 828 kg for an adult female. Despite its long neck and legs, the giraffe's body is relatively short. The skin of a giraffe is mostly gray, or tan, and can reach a thickness of 20 mm. The 80–100 centimetres long tail ends in a long, dark tuft of hair and is used as a defense against insects.
The coat has dark blotches or patches (which can be orange, chestnut, brown, or nearly black in colour) separated by light hair (usually white or cream in colour). Male giraffes become darker as they age. The coat pattern has been claimed to serve as camouflage in the light and shade patterns of savannah woodlands. When standing among trees and bushes, they are hard to see at even a few metres distance. However, adult giraffes move about to gain the best view of an approaching predator, relying on their size and ability to defend themselves rather than on camouflage, which may be more important for calves. Each individual giraffe has a unique coat pattern. Giraffe calves inherit some coat pattern traits from their mothers, and variation in some spot traits are correlated with neonatal survival. The skin underneath the blotches may serve as windows for thermoregulation, being sites for complex blood vessel systems and large sweat glands.
The fur may serve as a chemical defence, as its parasite repellents give the animal a characteristic scent. At least 11 main aromatic chemicals are in the fur, although indole and 3-methylindole are responsible for most of the smell. Because the males have a stronger odour than the females, the odour may also have sexual function.

Giraffes usually inhabit savannahs and open woodlands. They prefer Acacieae, Commiphora, Combretum and open Terminalia woodlands over denser environments like Brachystegia woodlands. The Angolan giraffe can be found in desert environments. Giraffes browse on the twigs of trees, preferring trees of the subfamily Acacieae and the genera Commiphora and Terminalia, which are important sources of calcium and protein to sustain the giraffe's growth rate. They also feed on shrubs, grass and fruit. A giraffe eats around 34 kg of foliage daily. When stressed, giraffes may chew the bark off branches. Giraffes are also recorded to chew old bones.
During the wet season, food is abundant and giraffes are more spread out, while during the dry season, they gather around the remaining evergreen trees and bushes. Mothers tend to feed in open areas, presumably to make it easier to detect predators, although this may reduce their feeding efficiency. As a ruminant, the giraffe first chews its food, then swallows it for processing and then visibly passes the half-digested cud up the neck and back into the mouth to chew again. The giraffe requires less food than many other herbivores because the foliage it eats has more concentrated nutrients and it has a more efficient digestive system. The animal's faeces come in the form of small pellets. When it has access to water, a giraffe drinks at intervals no longer than three days. Giraffes have a great effect on the trees that they feed on, delaying the growth of young trees for some years and giving "waistlines" to trees that are too tall. Feeding is at its highest during the first and last hours of daytime. Between these hours, giraffes mostly stand and ruminate.

Kordofan giraffe

The Kordofan giraffe is a subspecies of giraffe found in northern Cameroon, southern Chad, Central African Republic and possibly western Sudan. Historically some confusion has existed over the exact range limit of this subspecies compared to the West African giraffe, with populations in e.g. northern Cameroon formerly assigned to the latter. Genetic work has also revealed that all "West African giraffe" in European zoos are in fact Kordofan giraffe. It has been suggested that the Nigerian giraffe's ancestor dispersed from East to North Africa during the Quaternary period and thereafter migrated to its current Sahel distribution in West Africa in response to the development of the Sahara desert. Compared to most other subspecies, the Kordofan giraffe is relatively small at 3.8 to 4.7 meters, with more irregular spots on the inner legs. Its English name is a reference to Kordofan in Sudan. There are around 2,000 individuals living in the wild.
The Christian Science Monitor lists only 38 individuals being alive in the embattled Garamba National Park in The Democratic Republic of Congo due to poaching; their skin is used for luxury goods and they are said to produce enough meat to feed poachers for weeks. Recent genetic studies also shows distinct genetic populations of giraffes that makes conservation of these subspecies even more important.

Northern giraffe

The northern giraffe, also known as three-horned giraffe, is the type species of giraffe native to North Africa.
In the current IUCN taxonomic scheme, there is only one species of giraffe with the name G. camelopardalis and nine subspecies, but alternative taxonomic hypotheses have proposed two to eleven species.
Once abundant throughout Africa since the 19th century, it ranged from Senegal, Mali and Nigeria from West Africa to up north in Egypt. The West African giraffes once lived in Algeria and Morocco in ancient periods until their extinctions due to the Saharan dry climate. It is isolated in South Sudan, Kenya, Chad and Niger.
All giraffes are considered Vulnerable to extinction by the IUCN. In 2016, around 97,000 individuals from all subspecies were present in the wild. There are currently 5,195 northern giraffes.
The northern giraffe has two horn-like protuberances known as ossicones on their foreheads. The northern giraffe's are longer and larger than that of the southern giraffes', though bull northern giraffes have a third cylindrical ossicone in the center of the head just above the eyes which are from 3 to 5 inches long.

The Northern giraffes live in the savannahs, shrublands and woodlands. After local extinctions in various places, the Northern giraffes are the least numerous species and the most endangered. In East Africa, they are mostly found in Kenya and southwestern Ethiopia, though rarely in northeastern Democratic Republic of the Congo and South Sudan. There are about 2,000 in the Central African Republic, Chad and Cameroon of Central Africa. Once widespread in West Africa, a few hundreds of Northern giraffes are confined at the Dosso Reserve of Kouré, Niger. They are common both in and outside of protected areas.
The earliest ranges of the Northern giraffes were in Chad during the late Pliocene. were once abundant in North Africa. They lived in Algeria since early Pleistocene during the Quaternary period. They lived in Morocco until their extinction around the year AD 600, as the dry climate of the Sahara made conditions impossible for the giraffes. They are also extinct in Libya and Egypt.

Nubian giraffe

The Nubian giraffe is the nominate subspecies of giraffe. It is found in Ethiopia, Kenya, Uganda, South Sudan and Sudan. It is currently extinct in the wild of the Democratic Republic of Congo, Egypt and Eritrea. The Nubian giraffe used to be widespread everywhere on Northeast Africa. The subspecies was listed as Critically Endangered by the IUCN in 2018 for the first time due to a 95% decline in the past 3 decades.
Giraffes occurred everywhere in Africa; the Nubian giraffe was widespread throughout North Africa, from Kenya to Egypt. The giraffe lives in savannahs and woodlands. The Nubian giraffe currently lives in eastern South Sudan and southwestern Ethiopia, and isolated pockets in Uganda and Kenya. It was estimated in 2010 that fewer than 250 live in the wild, although this number was uncertain. However, as of 2016, it was recently estimated that 2,150 Nubian giraffes live in the wild, 1,500 of those of the Rothschild's ecotype. Fewer than 200 now live in western Ethiopia and about 450 in eastern South Sudan. There are 800 in Kenya and more than 1,550 in Uganda.

Rothschild's giraffe

Rothschild's giraffe is a subspecies of the Northern giraffe. It is one of the most endangered distinct populations of giraffe, with 1,669 individuals estimated in the wild in 2016.
The Rothschild's giraffe is easily distinguishable from other subspecies. The most obvious sign is in the coloring of the coat or pelt. Whereas the reticulated giraffe has very clearly defined dark patches with bright-whitish channels between them, Rothschild's giraffe more closely resembles the Masai giraffe. However, when compared to the Masai giraffe, the Rothschild's ecotype is paler, the orange-brown patches are less jagged and sharp in shape, and the connective channel is of a creamier hue compared to that seen on the reticulated giraffe. In addition, Rothschild's giraffe displays no markings on the lower leg, giving it the impression of wearing white stockings.
Another distinguishing feature of Rothschild's giraffe, although harder to spot, is the number of ossicones on the head. This is the only Giraffa phenotype to be born with five ossicones. Two of these are the larger and more obvious ones at the top of the head, which are common to all giraffes. The third ossicone can often be seen in the center of the giraffe's forehead, and the other two are behind each ear. They are also taller than many other populations, measuring up to 5.88 metres tall. They can weigh up to 2,500 pounds.

Males are larger than females by a few hundred pounds and their two largest ossicones are usually bald from sparring. They usually tend to be darker in colour than the females, although this is not a guaranteed sexing indicator.
Isolated populations of Rothschild's giraffes live in savannahs, grasslands, and open woodlands of Uganda and Kenya. They are possibly regionally extinct from South Sudan and northeastern Democratic Republic of the Congo.
Rothschild's giraffes mate at any time of the year and have a gestation period of 14 to 16 months, typically giving birth to a single calf. They live in small herds, with males and females (and their calves) living separately, only mixing for mating. The Rothschild's giraffes are tolerant of other animals around them as long as they don't feel threatened. For the most part, they are very friendly, but the males are known to engage in fights for mating. Since this species can mate all year long, those battles seem to be frequent.

West African giraffe

The West African giraffe, Niger giraffe or Nigerien giraffe, is a subspecies of the giraffe distinguished by its light colored spots, which is found in the Sahel regions of West Africa.
In the 19th century it ranged from Senegal to Lake Chad, yet in 2011 this subspecies only survives in a few isolated pockets containing about 400 individuals in total. Its last self-sustaining herd is in southwest Niger, supported by a series of refuges in Dosso Region, and the tourist center at Kouré, some 80 km southeast of Niamey. All captive so-called "West African giraffe" are now known to be the Kordofan giraffe.
The Nigerien giraffe population relies upon seasonal migration between the relatively drought-resistant lowlands of the Niger River valley and the drier highlands near Kouré. In this area, Tiger bush habitat allows for bands of trees to thrive in climates which might otherwise become more typical desert.
The West African giraffe survive primarily on a diet of leaves from Acacia albida and Hyphaene thebaica as well as Annona senegalensis, Parinari macrophylla, Piliostigma reticulatum, and Balanites aegyptiaca. In the late 1990s, an anti-desertification project for the area around Niamey encouraged the development of woodcutting businesses. An unintended effect of this was the destruction of much Tiger bush and giraffe habitat within the region. The Nigerien government has since moved to limit woodcutting in the area.

Reticulated giraffe

The reticulated giraffe, also known as the Somali giraffe, is a species of giraffe native to the Horn of Africa. It lives in Somalia, southern Ethiopia, and northern Kenya. There are approximately 8,500 individuals living in the wild. The reticulated giraffe was described and given its binomial name by British zoologist William Edward de Winton in 1899, however the IUCN currently recognizes only one species of giraffe with nine subspecies.
Reticulated giraffes can interbreed with other giraffe species in captivity or if they come into contact with populations of other species in the wild.
Together with the Rothschild's giraffe, it is by far the giraffe that is most commonly seen in zoos. Its coat consists of large, polygonal, liver-colored spots outlined by a network of bright-white lines. The blocks may sometimes appear deep red and may also cover the legs. Giraffes are the tallest mammals in the world.
Reticulated giraffes historically occurred widely throughout Northeast Africa. Their favored habitats are savannas, woodlands, seasonal floodplains, and rainforests.

Southern giraffe

The southern giraffe, also known as two-horned giraffe, is a proposed species of giraffe native to Southern Africa. However, the IUCN currently recognizes only one species of giraffe with nine subspecies.
Southern giraffes have rounded or blotched spots, some with star-like extensions on a light tan background, running down to the hooves. They range from South Africa, Angola, Namibia, Botswana, Zambia, Zimbabwe, Mozambique. Their approximate population is composed of 44,500 individuals.
The Cape subspecies of the southern giraffe has dark, somewhat rounded patches "with some fine projections" on a tawny background colour. The spots extend down the legs and get smaller. The median lump of bulls is less developed.
The southern giraffes live in the savannahs and woodlands of northern South Africa, Angola, southern Botswana, southern Zimbabwe, Zambia and south-western Mozambique. After local extinctions in various places, the South African giraffes have been reintroduced in many parts of Southern Africa, including in Swaziland. They are common in both inside and outside of protected areas.
Southern giraffes usually live in savannahs and woodlands where food plants are available. Southern giraffes are herbivorous mammals. They feed on leaves, flowers, fruits and shoots of woody plants such as Acacia.

South African giraffe

The South African giraffe or Cape giraffe is a subspecies of giraffe ranging from South Africa, Namibia, Botswana, Zimbabwe, Mozambique. It has rounded or blotched spots, some with star-like extensions on a light tan background, running down to the hooves.
The South African giraffe has dark, somewhat rounded patches "with some fine projections" on a tawny background colour. The spots extend down the legs and get smaller. The median lump of males is less developed.
The South African giraffe is found in northern South Africa, southern Botswana, southern Zimbabwe, and south-western Mozambique. After local extinctions in various places, the South African giraffes have been reintroduced in many parts of Southern Africa, including in Eswatini. They are common in both in and outside of protected areas. South African giraffes usually live in savannahs and woodlands where food plants are available. Giraffes are herbivorous animals. They feed on leaves, flowers, fruits and shoots of woody plants such as Acacia.
South African giraffes live in a fission-fusion society system based on things such as sex, age, season, and kinship. This allows them to adapt better to environmental changes around them.

Masai giraffe

The Masai giraffe, also spelled Maasai giraffe, also called Kilimanjaro giraffe, is the largest species of giraffe. It is native to East Africa. The Masai giraffe can be found in central and southern Kenya and in Tanzania. It has distinctive, irregular, jagged, star-like blotches that extend to the hooves. A median forehead lump is usually present in bulls.
The Masai giraffe is distinguished by jagged spots on its body, geographic range including southern Kenya and all of Tanzania, and genetic evidence. It is the largest-bodied giraffe species, making it the tallest land animal on Earth.

Rhodesian giraffe

The Rhodesian giraffe, more commonly known as Thornicroft’s giraffe, is a subspecies of giraffe. It is sometimes deemed synonymous with the Luangwa giraffe. It is geographically isolated, occurring only in Zambia’s South Luangwa Valley. An estimated 550 live in the wild, with no captive populations. The lifespan of the Rhodesian giraffe is 22 years for males and 28 years for females. The ecotype was originally named after Harry Scott Thornicroft, a commissioner in what was then North-Western Rhodesia and later Northern Rhodesia.
Rhodesian giraffes are tall with very long necks. They have long, dark-colored tongues and skin-colored horns. Giraffes have a typical coat pattern, with regional differences among subspecies. The pattern consists of large, irregular shaped brown to black patches separated by white to yellow bands. Male giraffes' coats darken with age, particularly the patches. The darkening of the coat has not been studied extensively enough to indicate absolute age, however it can estimate relative age of male Rhodesian giraffes.
Giraffes occur in arid and dry-savannah zones in sub-Saharan Africa, provided trees are available as a food source (IUCN). The Rhodesian giraffe is endemic to Zambia. Giraffes are herd animals with an extremely flexible social system.