Hippopotamus amphibius

(Jrt)

Hippopotamus
The hippopotamus (hippopotamus in Latin, Greek ἵππόποταμος hippopotamos, literally "horse of the river") is a herbivorous mammal of Africa, which weighed up to 4 tons.

The hippopotamus also said spends his days in groups of about twenty people in freshwater and muddy. Indeed, it transpires much more than most animals, and is very vulnerable to sunburn. It can close its nostrils and remain completely submerged up to ten minutes. It fleet and is very agile in the water. It also feeds on dry land, there aventurant especially at night. It eats up to 50 kg of vegetation a day.

Despite its air village, it is among the most dangerous animals to humans. Its canines measured 50 inches long, and it can load to 45 km / h.

Males demarcate their territory by projecting several metres away their excrement, urine and feces, accompanying their rapid evacuation of a circular movement of their tail-shaped brush.

This is the 3rd mammal (land) in weight after the elephant and rhinoceros. His height at is approximately 1.5 m, and it can measure 5 m long, for a hippopotamus.

Characteristics
The hippos are gregarious animals, living in groups of up to 40 warheads. Their life span is usually 40 to 50 years. Females reach sexual maturity at 5 or 6 years and have a gestation period of 8 months.

The hippos measure averaged 3.5 metres long and 1.5 metres tourniquet to a mass of 1500 kg to 3200 kg. They have roughly the same size as the white rhino and experts to discuss which of the two is the largest land animal after the elephant. Males seem to continue to grow throughout their lives, while females reach their maximum weight to the age of 25, they are also smaller than the males and do not normally weigh more than 1500 kg. It often gives 3200 kg as the upper limit for the mass of a male hippopotamus. Yet, there were copies of the greatest, one of whom was almost 5000 kg. Despite their heavy, they can run faster than a man on the mainland. It is estimated that their speed can range from 30 km / h to 40 km / h, or 48 km / h. However, they can not support such a speed that a few hundred meters.

The eyes, ears and nostrils of the hippopotamus are high. This allows them to spend most of the day with their bodies submerged in the waters of tropical rivers, to stay cool and prevent sunburn. To further protect from the sun, their skin secretes a kind of natural sunscreen reddish. This secretion is sometimes called "sweat blood", but this is actually neither blood nor sweat. First colorless, it turned orange-red after a few minutes, and finally becomes brown.

Two different pigments were identified in the secretions, a red and orange pigments two extremely acidic. It calls the red pigment hipposudorique acid and acid orange pigment norhipposudorique. It was found that the red pigment inhibits the growth of pathogenic bacteria, which leads to believe that the secretion has an antibiotic effect. The absorption of light by these two pigments is maximal in the ultraviolet range, which is equivalent to the effect of a sunscreen. As hippos secrete these pigments anywhere in the world, it does not seem that it is the foods that are the source. Rather animals can synthesize pigment from precursors such as tyrosine, which is an amino acid. (Saikawa et al. 2004)

As its name indicates, the ancient Greeks saw the hippo a sort of horse. Until 1985, naturalists included hippos with pigs, based on the peculiarities of the molars. Yet, the study of blood proteins, and of molecular systematics and more recently of fossils has shown that their genetic parents are closest cetaceans: whales, porpoises and related animals. The hippos have more in common with the whales they have with other hoofed animals such as pigs. Thus, the common ancestor of hippos and whales existed after the line was separated from ruminants, which separated itself occurred after the divergence from the rest of artiodactyls hoofed animals, including pigs. While the whale and the hippo are the closest living relatives of each other, the separation of their lineages occurred shortly after their divergence from the rest of ungulates artiodactyls.

Habitat
Before the last ice age, hippopotamus was widespread in North Africa and Europe, because it can live in colder climates provided that the water does not freeze in winter. It is now extinct in Egypt, where it was common to see him in the Nile during historical times. Pliny the Elder wrote that in his day the best place to Egypt for the capture was appointed to Saïs (NH 28121), and we could always find the long arm of Damietta after the Conquest Arabic (639). Even on the island of Malta, at Għar Dalam (the Cave of Darkness), hippopotamus bones were found, dating to about 180000 years. The hippos still exist in the rivers of Uganda, Sudan, in the north of the Democratic Republic of Congo and in northern Ethiopia, in the west of Gambia as well as in Southern Africa (Botswana, South Africa, Zimbabwe, Zambia). A separate population lives in Tanzania and Mozambique.

Less common, the pygmy hippopotamus of West Africa, Hexaprotodon (Choeropsis) liberiensis, is represented by two populations. The first Guinea, Sierra Leone, Liberia and Cote d'Ivoire. The other population, with a different shape of the skull, lived until recently in the Niger Delta, but now needs to be extinguished.


Lifestyle
The hippos are extremely territorial, a male hippo often marks its territory along a river bank where he keeps his harem of females, it defends against other males. The male hippopotamus challenge with yawning threatening. Their canines measured 50 centimetres long and they use their head as a battering ram, especially against rival males when they are fighting for their territory. The hippo does not attack humans, but extremely territorial, he defends his field against them vigorously and, as its habitat is often invaded by farmers and by tourists, it is among the most dangerous animals in Africa . They say it causes more deaths in humans than any other mammal.

The hippos almost always live in shallow water, often in deep water. Most of the hippos that have air buoyancy are actually standing or lying on the bottom. They feed mainly on land during the night, consuming up to 50 kg of vegetation a day. It has been observed that they consume from time to time of the meat found in trash near their habitat, but they are not really of carnivores.

The hippos adults generally do not float. In deep water, they propel usual jumps, pushing on the merits. It was noted that they travel at 8 km / h in the water. Young hippos swim more likely, by propelling through kicked their legs back. A young hippopotamus survived after being thrown into the sea during the tsunami generated by the earthquake in the Indian Ocean in 2004 and was raised on a nearby island.

Babies born hippos under water and weigh between 27 and 50 kg, they must rise to the surface for its first breath. Young people are often on the backs of their mothers when the water is too deep for them to immerse themselves and suckle.


The adult hippos usually surface to breathe every 3-5 minutes. Young people must breathe every 2-3 minutes. The process of rising surface and breathing is automatic and even a hippo sleeping and boost respirera without awakening. There has been hippopotamus remaining submersion up to 30 minutes. In this situation it is closing its nostrils.

Extinction
Three species of hippos have disappeared in Madagascar during the Holocene, one of which there are only a thousand years. A dwarf species, Phanourios minutis, lived on the island of Cyprus, Aetokremnos but disappeared in the late Pleistocene. Discussions over whether to criminalize human intervention.

In 2005, the population of hippos Virunga National Park in the Democratic Republic of Congo had fallen to 800 or 900 people when it had about 29000 in the mid-1970's, causing concern about the survival of the population . This decline is attributed to the damage caused by the Second War of the Congo. It is believed that poachers are former Hutu rebels, poorly paid Congolese soldiers and local militia. Poachers hunt for food, but also for financial profit. A three-ton hippopotamus is worth thousands of dollars. The sale of meat from hippo is illegal, but when she arrived unexpectedly in the markets, it is selling so fast that it is difficult for staff to intervene WWF. The environmentalists warn that the hippo will soon have disappeared from Congo. The slaughter of animals in the park has long been backed by the Rwandan army in the natural parks in Congo.


Status of conservation and research
It was suggested that the hippopotamus population of the whole of Africa is between 125000 and 150000, which the Zambia (40000) and Tanzania (20000 -30 000) have the largest populations.

It described five sub-species of hippos on the basis of morphological differences (Ha amphibius, kiboko Ha, Ha capensis, tschadensis Ha, Ha constrictus; Lydekker 1915). However, the existence of these alleged sub-species had not been confirmed by genetic analysis, this was done by a recent study Okello et al. (2005).

By using mitochondrial DNA from skin biopsies taken from 13 sampling sites, the authors reviewed the diversity and genetic structure among populations of hippos across the continent. They find that the genetic differentiation is low but significant among 3 groups of 5 suspects - Ha Amphibius, H.a. Capensis, H.a. Kiboko. If these conclusions are correct, it would mean that the common hippopotamus in Kenya and Somalia (kiboko), South Africa (capensis from Zambia to South Africa) and the rest of sub-Saharan African countries (amphibius ) represent three distinct sub-species, with Ha Amphibius as ancestral group. Okello et al. Have established that the common hippopotamus in Africa have experienced a significant population growth during the Pleistocene and later expansion which they attribute to an increase in water bodies at the end of that time.

These findings have important implications for conservation. The hippopotamus populations across the continent are threatened by the loss of their habitat and the uncontrolled hunting. And it will not be enough to combat these threats, we must also preserve the genetic diversity of these three distinct sub-species. The hippopotamus was placed on the so-called "Red List" established by the Union for the World Conservation (IUCN) in May 2006. That shows that the common hippopotamus is now in serious danger of extinction.

Myths & literatures
The animal, familiar Nile, lends his face massive Tawaret ( "The Great"), the goddess of hippopotamus Egyptian pantheon, but also the monster Behemoth of the Hebrews (hippopotamus being feared for his aggressiveness).

Thereafter scholars Greek Herodotus and Aristotle who do know him only through hearsay, were the affubler advises of hooves and mane of a horse he would keep in the representations of zoologists to the Renaissance.

It was not until Pierre Belon who sees a hippo in Constantinople to be denied fables passed by the writings of the ancients. An ancient statue of the Nile, in the gardens of the Belvedere Pope, who represents the zoologist assured that this is the same animal.

The scientific expeditions make the following centuries hippopotamus familiar to naturalists, before the colonial expansion of Western nations do not enter the bestiary common to the West.

Citation
"I adorais because it looked like a big beast, I am the figurais simply as a hippopotamus, and the table ravissait me because of his candor and accuracy, because without friends with a bad influence, he had to expect any adverse climates, and is tantamount Indies or Sumatra, or wherever. "
Arthur Cravan, Oscar Wilde is alive!, 1913 (now No. 3, No. sp. 1)

Read also Hippopotamus

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