Hippopotamus amphibius Linnaeus, 1758, Nile River, Egypt. Five subspecies have been described, although it’s uncertain that they’re legitimate. No exterior variations between them have been famous.
OTHER COMMON NAMES
English: River hippopotamus; French: Hippopotame; German: Grossflusspferd; Spanish: Hipopotamo.
The frequent hippo has a shoulder peak of 54–60 in (137–152 cm), size up to 106 in (270 cm), and weighs up to 4,000 lb (1,800 kg). It has a rotund physique with disproportionately quick legs. The thick purple-brown pores and skin seems hairless, with just a few bristles across the mouth and on the tail, however there’s a masking of very effective hairs at low density over the entire of the physique.
The head is giant with a large mouth that opens to a gape of practically 180°. The variety of tooth is barely diminished within the frequent hippo to (I2/2, C1/1, P3/3, M3/3) 2 36, though generally the fourth milk premolar is retained within the grownup jaw.
The frequent hippopotamus happens in some 35 sub-Saharan international locations, however many populations are extraordinarily small, particularly in West Africa, the place the hippos are fragmented into remoted teams every containing a number of dozen on the most. Countries with substantial populations are located within the japanese and southern elements of the continent of Africa and embrace Zambia, Democratic Republic of the Congo (Zaire), and Tanzania.
During the day, the hippo is present in shallow freshwater aquatic habitats, which can be rivers, lakes, wallows, or any wetland that retains the pores and skin moist. Wet mud is appropriate, and hippos typically happen in wallows which might be drying out. At evening, the hippo leaves the water to graze in grasslands which may be a mile (1.6 km) or extra from its daytime retreat. It reaches the grazing areas by following well-worn trails.
There have been few investigations into the habits of the hippo as it’s a troublesome species to research and conclusions about its actions will not be of common applicability. The most detailed research, set in Uganda, reported that though the hippo is very colonial within the water, it exhibits little in the way in which of a social life and is basically solitary when grazing at evening. The solely social bond is that between a feminine and her dependent calves. Males are territorial within the water and preserve mating rights over the females inside a defended size of shoreline. It isn’t a harem system, nevertheless, for the females don’t essentially return to the identical territory on daily basis. The territory could comprise bachelor teams, that are tolerated by the territorial male supplied they behave submissively on assembly. Fierce combating could happen if a bachelor challenges the territory holder and the loss of life of one of many combatants could observe. Hippos usually are not territorial on land. The spraying of bushes with feces happens when the hippo vigorously wags its tail whereas defecating, thus spreading the droppings far and broad. The function isn’t clear however it could have a social operate as a dominance show or probably the deposits could serve to orientate the hippo throughout its nocturnal wanderings.
The bellows of hippos are well-known, although their function in communication isn’t clear. In addition to the aerial sounds, hippos vocalize underneath water, producing a minimum of three sorts of name, together with tonal whines, pulsed croaks, and clicks, all of which seem to be related to communication. Some calls are amphibious and go via the air and water concurrently.
FEEDING ECOLOGY AND DIET
The frequent hippopotamus is predominantly a grazer. It plucks the grass with its lips, nipping it off shut to the bottom thereby creating short-grass patches generally known as hippo lawns. Relative to its weight, the hippo consumes much less food than different herbivores, probably reflecting its decrease metabolic charge. The hippo is in a position to lengthen its grazing vary within the moist season by making use of non permanent wallows for daytime resting thus obviating the necessity to trek again to everlasting water on daily basis. However, it doesn’t feed on aquatic vegetation to any extent. Carnivory, primarily via scavenging, has been reported a number of occasions, together with a case of cannibalism.
Common Hippo is polygamous. The hippo mates within the water with the feminine remaining submerged aside from when she breaks floor to breathe. The gestation interval of 240 days is brief for such a big animal. The feminine withdraws from the herd earlier than giving start, which normally takes place within the water. The weight of the neonate is about 110 lb (50 kg). Normally, just one calf is produced at a time, although twins do happen at a low charge, which in Uganda was discovered to be 0.7%. The intercourse ratio at start is 1:1.
Births happen all year long on the equator, however there are peaks related to rainfall, with most births going down firstly of the moist season. Away from the equator, the place rainfall is extra seasonal, there are some dry season months when there are not any births in any respect.
The period of lactation is unknown; it’s in all probability of the order of 1 12 months. The calf stays with its mom after the second calf is born, however leaves earlier than the onset of puberty, which in Uganda was estimated to be at about 7.5 years of age within the male and 9 years within the feminine.
The frequent hippo is placed on Appendix II of CITES. It isn’t in rapid hazard over a lot of its vary in southern and east Africa, however the outlook in West Africa is bleak. The whole quantity is low, and the remaining animals are scattered in small teams wherein genetic Challenges ensuing from inbreeding could also be anticipated.
SIGNIFICANCE TO HUMANS
The hippo is a harmful animal that’s liable for quite a few human deaths annually, significantly of fishermen. It additionally raids crops, significantly rice. It is, in flip, hunted for meat and ivory; a number of the human deaths happen throughout makes an attempt to harpoon the animal. The hippo options in African folklore.