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117-522: The Upper West Region is one of the 16 regions of Ghana. It is located at the northwestern corner of Ghana at latitude 9.8°- 11.O° North and longitude 1.6°- 3.0 West, bounded by Burkina Faso to the North. It covers a geographical area of 18,476 square kilometres, representing 12.7% of the total land area of Ghana. The northern Ghana-Burkina Faso is bordered on the east by the Upper East region and Northern regions, on

234-408: A tapetum lucidum ; these adaptations allow for large amounts of light to pass through the eye and, therefore, a very clear image of the surrounding area. They also have glands on the eyelids and outer corneal layer that act as protection for the cornea. The olfactory lobes are absent in toothed whales, suggesting that they have no sense of smell. Some whales, such as the bowhead whale , possess

351-485: A vomeronasal organ , which does mean that they can "sniff out" krill. Whales are not thought to have a good sense of taste, as their taste buds are atrophied or missing altogether. However, some toothed whales have preferences between different kinds of fish, indicating some sort of attachment to taste. The presence of the Jacobson's organ indicates that whales can smell food once inside their mouth, which might be similar to

468-431: A US$ 73 million exhibit to house three adult hippos, featuring a 250,000 L (55,000 imp gal; 66,000 US gal) tank. Modern hippo enclosures also have a complex filtration system for the animal's waste, an underwater viewing area for the visitors, and glass that may be up to 9 cm (3.5 in) thick and capable of holding water under pressures of 31 kPa (4.5 psi). In Egyptian mythology ,

585-628: A ballerina hippo dancing to the opera La Gioconda . The film Hugo the Hippo is set in Tanzania and involves the title character trying to escape being slaughtered with the help of local children. The Madagascar films feature a hippo named Gloria . Hippos even inspired a popular board game, Hungry Hungry Hippos . Whale Whales are a widely distributed and diverse group of fully aquatic placental marine mammals . As an informal and colloquial grouping, they correspond to large members of

702-733: A different reason for it, for example, the killer whale was named "Ballena asesina" 'killer whale' by Spanish sailors. The term "Great Whales" covers those currently regulated by the International Whaling Commission : the Odontoceti family Physeteridae (sperm whales); and the Mysticeti families Balaenidae (right and bowhead whales), Eschrichtiidae (grey whales), and some of the Balaenopteridae (Minke, Bryde's, Sei, Blue and Fin; not Eden's and Omura's whales). The whales are part of

819-614: A factor in their eventual extinction. Isolated individual Malagasy hippos may have survived in remote pockets; in 1976, villagers described a living animal called the kilopilopitsofy , which may have been a Malagasy hippo. Hippopotamus gorgops from the Early Pleistocene to the early Middle Pleistocene of Africa and West Asia grew considerably larger than the living hippopotamus, with an estimated body mass of over 4,000 kg (8,800 lb). Hippopotamus antiquus ranged throughout Europe, extending as far north as Britain during

936-570: A form of tourism around the world. The word "whale" comes from the Old English hwæl , from Proto-Germanic *hwalaz , from Proto-Indo-European *(s)kwal-o- , meaning "large sea fish". The Proto-Germanic *hwalaz is also the source of Old Saxon hwal , Old Norse hvalr , hvalfiskr , Swedish val , Middle Dutch wal , walvisc , Dutch walvis , Old High German wal , and German Wal . Other archaic English forms include wal, wale, whal, whalle, whaille, wheal , etc. The term "whale"

1053-455: A great distance across South Africa . The hippo is considered to be extremely aggressive and has frequently been reported charging and attacking boats. Small boats can easily be capsized by hippos and passengers can be injured or killed by the animals, or drown in the water. In one 2014 case in Niger , a boat was capsized by a hippo and 13 people were killed. Hippos will often raid farm crops if

1170-425: A high-pitched squeal followed by a deeper, resonant call. The animals can recognise the calls of other individuals. Hippos are more likely to react to the wheeze honks of strangers than to those they are more familiar with. When threatened or alarmed, they produce exhalations, and fighting bulls will bellow loudly. Hippos are recorded to produce clicks underwater which may have echolocative properties. They have

1287-524: A long snout. Their skeletal structures are graviportal , adapted to carrying their enormous weight, and their dense bones and low centre of gravity allows them to sink and move along the bottom of the water. Hippopotamuses have small legs (relative to other megafauna ) because the water in which they live reduces the weight burden. The toes are webbed and the pelvis rests at an angle of 45 degrees. Though chubby-looking, hippos have little fat. The eyes, ears, and nostrils of hippos are placed high on

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1404-599: A presiding member elected from among the members themselves. The current list is as follows: Prominent and famous citizens of Upper West Region include: Festivals that take place in the Upper West Region include: 10°20′N 2°15′W  /  10.333°N 2.250°W  / 10.333; -2.250 Hippopotamus The hippopotamus ( Hippopotamus amphibius ) ( / ˌ h ɪ p ə ˈ p ɒ t ə m ə s / ; pl. : hippopotamuses ; often shortened to hippo ( pl. : hippos ), further qualified as

1521-420: A small bulge sitting on top of its skull, whereas a sperm whale's head is filled up mainly with the melon. The whale eye is relatively small for its size, yet they do retain a good degree of eyesight. As well as this, the eyes of a whale are placed on the sides of its head, so their vision consists of two fields, rather than a binocular view like humans have. When belugas surface, their lens and cornea correct

1638-456: A strong desire on behalf of the whales to communicate with humans, as whales have a very different vocal mechanism, so imitating human speech likely takes considerable effort. Whales emit two distinct kinds of acoustic signals, which are called whistles and clicks: Clicks are quick broadband burst pulses, used for sonar , although some lower-frequency broadband vocalizations may serve a non-echolocative purpose such as communication; for example,

1755-429: A two- to three-chambered stomach that is similar in structure to those of terrestrial carnivores. Mysticetes contain a proventriculus as an extension of the oesophagus ; this contains stones that grind up food. They also have fundic and pyloric chambers. Whales have two flippers on the front, and a tail fin. These flippers contain four digits. Although whales do not possess fully developed hind limbs, some, such as

1872-432: A variety of plants if presented with them in captivity, but their diet in nature consists almost entirely of grass, with only minimal consumption of aquatic plants. Hippos spend most of the day in water to stay cool and hydrated. Just before night begins, they leave the water to forage on land. A hippo will travel 3–5 km (1.9–3.1 mi) per night, eating around 40 kg (88 lb) of grass. By dawn, they are back in

1989-815: Is Lu the Hippo, from the Ellie Schiller Homosassa Springs Wildlife State Park . As of 2024, he is 64 years old. Hippopotamus amphibius arrived in Europe around 560–460,000 years ago, during the Middle Pleistocene. The distribution of Hippopotamus amphibius in Europe during the Pleistocene was largely confined to Southern Europe, including the Iberian Peninsula, Italy, and Greece, but extended into northwestern Europe, including Great Britain (as far north as North Yorkshire ),

2106-611: Is an example of mutualism , in which the hippo benefits from the cleaning while the fish receive food. Hippo defecation creates allochthonous deposits of organic matter along the river beds. These deposits have an unclear ecological function. A 2015 study concluded hippo dung provides nutrients from terrestrial material for fish and aquatic invertebrates, while a 2018 study found that their dung can be toxic to aquatic life in large quantities, due to absorption of dissolved oxygen in water bodies. The parasitic monogenean flatworm Oculotrema hippopotami infests hippopotamus eyes, mainly

2223-524: Is around 1,480 kg (3,260 lb) for bulls and 1,365 kg (3,009 lb) for cows. Exceptionally large males have been recorded reaching 2,660 kg (5,860 lb). Male hippos appear to continue growing throughout their lives, while females reach maximum weight at around age 25. It is 2.90 to 5.05 m (9 ft 6 in to 16 ft 7 in) long, including a tail of about 35 to 56 cm (14 to 22 in) in length and 1.30 to 1.65 m (4 ft 3 in to 5 ft 5 in) tall at

2340-571: Is attributed to the disruptions caused by the Second Congo War . The poachers are believed to be Mai-Mai rebels, underpaid Congolese soldiers, and local militia groups. Reasons for poaching include the belief hippos are harmful to society, as well as financial gain. As of 2016, the Virunga hippo population appears to have increased again, possibly due to better protection from park rangers, who have worked with local fishermen. The sale of hippo meat

2457-411: Is capable of running 30 km/h (19 mph) over short distances. Hippos inhabit rivers, lakes, and mangrove swamps. Territorial bulls each preside over a stretch of water and a group of five to thirty cows and calves. Mating and birth both occur in the water. During the day, hippos remain cool by staying in water or mud, emerging at dusk to graze on grasses. While hippos rest near each other in

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2574-515: Is characterized by the presence of baleen, a sieve-like structure in the upper jaw made of keratin , which it uses to filter plankton , among others, from the water. Odontocetes (toothed whales) are characterized by bearing sharp teeth for hunting, as opposed to their counterparts' baleen. Cetaceans and artiodactyls now are classified under the order Cetartiodactyla , often still referred to as Artiodactyla, which includes both whales and hippopotamuses . The hippopotamus and pygmy hippopotamus are

2691-473: Is common among small mammals such as rodents). Calves no longer need to suckle when they are a year old. Hippos coexist alongside a variety of large predators in their habitats. Nile crocodiles , lions , and spotted hyenas are known to prey on young hippos. Beyond these, adult hippos are not usually preyed upon by other animals due to their aggression and size. Cases where large lion prides have successfully preyed on adult hippos have been reported, but it

2808-809: Is generally rare. Lions occasionally prey on adults at Gorongosa National Park and calves are sometimes taken at Virunga. Crocodiles are frequent targets of hippo aggression, probably because they often inhabit the same riparian habitats; crocodiles may be either aggressively displaced or killed by hippos. In turn, very large Nile crocodiles have been observed preying occasionally on calves, "half-grown" hippos, and possibly also adult female hippos. Groups of crocodiles have also been observed finishing off still-living male hippos that were previously injured in mating battles with other males. Hippos occasionally visit cleaning stations in order to be cleaned of parasites by certain species of fishes. They signal their readiness for this service by opening their mouths wide. This

2925-437: Is helpful for a 100-ton whale), protection to some extent as predators would have a hard time getting through a thick layer of fat, and energy for fasting when migrating to the equator; the primary usage for blubber is insulation from the harsh climate. It can constitute as much as 50% of a whale's body weight. Calves are born with only a thin layer of blubber, but some species compensate for this with thick lanugos. Whales have

3042-406: Is home to elongated spindle neurons that, prior to 2007, were known only in hominids. In humans, these cells are involved in social conduct, emotions, judgement, and theory of mind. Whale spindle neurons are found in areas of the brain that are homologous to where they are found in humans, suggesting that they perform a similar function. Brain size was previously considered a major indicator of

3159-482: Is illegal, but black-market sales are difficult for Virunga National Park officers to track. Hippo meat is highly valued in some areas of central Africa and the teeth may be used as a replacement for elephant ivory. A population of hippos exists in Colombia , descended from captive individuals that escaped from Pablo Escobar 's estate after his death in 1993. Their numbers grew to 100 by the 2020s and ecologists believe

3276-442: Is in their feeding adaptations and subsequent behaviour. Balaenopterids are the rorquals. These animals, along with the cetotheriids, rely on their throat pleats to gulp large amounts of water while feeding. The throat pleats extend from the mouth to the navel and allow the mouth to expand to a large volume for more efficient capture of the small animals they feed on. Balaenopterids consist of two genera and eight species. Balaenids are

3393-404: Is mostly purplish-grey or blue-black, but brownish-pink on the underside and around the eyes and ears. Their skin secretes a natural, red-coloured sunscreen substance that is sometimes referred to as "blood sweat" but is neither blood nor sweat. This secretion is initially colourless and turns red-orange within minutes, eventually becoming brown. Two highly acidic pigments have been identified in

3510-492: Is powered by huge masseter and digastric muscles which give them large, droopy cheeks. The jaw hinge allows the animal to open its mouth at almost 180°. A folded orbicularis oris muscle allows the hippo to attain an extreme gape without tearing any tissue. On the lower jaw, the incisors and canines grow continuously, the former reaching 40 cm (16 in), while the latter can grow to up to 50 cm (20 in). The lower canines are sharpened through contact with

3627-438: Is sometimes used interchangeably with dolphins and porpoises , acting as a synonym for Cetacea . Six species of dolphins have the word "whale" in their name, collectively known as blackfish: the orca , or killer whale, the melon-headed whale , the pygmy killer whale , the false killer whale , and the two species of pilot whales , all of which are classified under the family Delphinidae (oceanic dolphins). Each species has

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3744-442: Is taken in and expelled. They are warm-blooded , and have a layer of fat, or blubber , under the skin. With streamlined fusiform bodies and two limbs that are modified into flippers, whales can travel at speeds of up to 20 knots , though they are not as flexible or agile as seals . Whales produce a great variety of vocalizations, notably the extended songs of the humpback whale . Although whales are widespread, most species prefer

3861-611: Is the genus Kenyapotamus , which lived in Africa from 15 to 9 million years ago . Hippopotamid species would spread across Africa and Eurasia, including the modern pygmy hippo. From 7.5 to 1.8 million years ago , a possible ancestor to the modern hippo, Archaeopotamus , lived in Africa and the Middle East. The oldest records of the genus Hippopotamus date to the Pliocene (5.3–2.6 million years ago). The oldest unambiguous records of

3978-401: Is then expelled through the baleen, leaving their prey trapped inside. This is an efficient method of hunting, in which the whale has no major competitors. Odontocetes are known as toothed whales; they have teeth and only one blowhole. They rely on their well-developed sonar to find their way in the water. Toothed whales send out ultrasonic clicks using the melon . Sound waves travel through

4095-706: Is typically 40 to 50 years. Donna the Hippo was one of the oldest living hippos in captivity. She lived at the Mesker Park Zoo in Evansville, Indiana , in the US until her death in 2012 at the age of 61. The oldest hippo ever recorded was called Bertha; she had lived in the Manila Zoo in the Philippines since it first opened in 1959. When she died in 2017, her age was estimated to be 65. The oldest living hippopotamus in captivity

4212-562: The Indohyus , an extinct chevrotain -like ungulate, from which they split approximately 48 million years ago. Primitive cetaceans, or archaeocetes , first took to the sea approximately 49 million years ago and became fully aquatic 5–10 million years later. What defines an archaeocete is the presence of anatomical features exclusive to cetaceans, alongside other primitive features not found in modern cetaceans, such as visible legs or asymmetrical teeth. Their features became adapted for living in

4329-584: The Bouri Formation and dated to around 160,000 years ago. 4,000–5,000 year art showing hippos being hunted have been found in the Tassili n'Ajjer Mountains of the central Sahara near Djanet . The ancient Egyptians recognised the hippo as ferocious, and representations on the tombs of nobles show humans hunting them. The hippo was also known to the Greeks and Romans . The Greek historian Herodotus described

4446-551: The Early and Middle Pleistocene epochs, before being replaced by the modern H. amphibius in Europe during the latter part of the Middle Pleistocene. The Pleistocene also saw a number of dwarf species evolve on several Mediterranean islands, including Crete ( Hippopotamus creutzburgi ), Cyprus (the Cyprus dwarf hippopotamus , Hippopotamus minor ), Malta ( Hippopotamus melitensis ), and Sicily ( Hippopotamus pentlandi ). Of these,

4563-710: The IUCN Red List drawn up by the International Union for Conservation of Nature (IUCN) lists the species as vulnerable , with a stable population estimated between 115,000 and 130,000 animals. The hippo population has declined most dramatically in the Democratic Republic of the Congo. By 2005, the population in Virunga National Park had dropped to 800 or 900 from around 29,000 in the mid-1970s. This decline

4680-468: The Monodontidae (belugas and narwhals), Physeteridae (the sperm whale ), Kogiidae (the dwarf and pygmy sperm whale), and Ziphiidae (the beaked whales), as well as the six families of dolphins and porpoises which are not considered whales in the informal sense. Whales are fully aquatic, open-ocean animals: they can feed, mate, give birth, suckle and raise their young at sea. Whales range in size from

4797-541: The beluga and the narwhal . They both reside in the frigid arctic and both have large amounts of blubber. Belugas, being white, hunt in large pods near the surface and around pack ice, their coloration acting as camouflage. Narwhals, being black, hunt in large pods in the aphotic zone, but their underbelly still remains white to remain camouflaged when something is looking directly up or down at them. They have no dorsal fin to prevent collision with pack ice. Physeterids and Kogiids consist of sperm whales . Sperm whales consist

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4914-433: The blowhole , forming an upward, steamy spout, followed by inhaling fresh air into the lungs; a humpback whale's lungs can hold about 5,000 litres (1,300 US gal) of air. Spout shapes differ among species, which facilitates identification. All whales have a thick layer of blubber . In species that live near the poles, the blubber can be as thick as 11 inches (28 cm). This blubber can help with buoyancy (which

5031-426: The common hippopotamus , Nile hippopotamus , or river hippopotamus , is a large semiaquatic mammal native to sub-Saharan Africa . It is one of only two extant species in the family Hippopotamidae , the other being the pygmy hippopotamus ( Choeropsis liberiensis or Hexaprotodon liberiensis ). Its name comes from the ancient Greek for "river horse" ( ἱπποπόταμος ). After elephants and rhinoceroses ,

5148-436: The fossil record , show their closest living relatives are cetaceans ( whales , dolphins , and porpoises ). The common ancestor of hippos and whales branched off from Ruminantia and the rest of the even-toed ungulates; the cetacean and hippo lineages split soon afterwards.   Tylopoda   Suina        Ruminantia   Hippopotamidae   Cetacea The most recent theory of

5265-405: The marine environment . Major anatomical changes included their hearing set-up that channeled vibrations from the jaw to the earbone ( Ambulocetus 49 mya ), a streamlined body and the growth of flukes on the tail ( Protocetus 43 mya), the migration of the nostrils toward the top of the cranium ( blowholes ), and the modification of the forelimbs into flippers ( Basilosaurus 35 mya), and

5382-417: The photic zone . Ziphiids consist of 22 species of beaked whale . These vary from size, to coloration, to distribution, but they all share a similar hunting style. They use a suction technique, aided by a pair of grooves on the underside of their head, not unlike the throat pleats on the rorquals , to feed. As a formal clade (a group which does not exclude any descendant taxon ), odontocetes also contains

5499-424: The porpoises (Phocoenidae) and four or five living families of dolphins: oceanic dolphins ( Delphinidae ), South Asian river dolphins ( Platanistidae ), the possibly extinct Yangtze River dolphin ( Lipotidae ), South American river dolphins ( Iniidae ), and La Plata dolphin (Pontoporiidae). Whales are descendants of land-dwelling mammals of the artiodactyl order (even-toed ungulates). They are related to

5616-758: The wet season . Male hippos always have mobile spermatozoa and can breed year-round. After becoming pregnant, a female hippo will typically not begin ovulation again for 17 months. Hippos mate in the water, with the cow remaining under the surface, her head emerging periodically to draw breath. Cows give birth in seclusion and return within 10 to 14 days. Calves are born on land or shallow water weighing on average 50 kg (110 lb) and at an average length of around 127 cm (50 in). The female lies on her side when nursing, which can occur underwater or on land. The young are carried on their mothers' backs in deep water. Mother hippos are very protective of their young, not allowing others to get too close. One cow

5733-484: The 2.6 metres (8.5 ft) and 135 kilograms (298 lb) dwarf sperm whale to the 29.9 metres (98 ft) and 190 tonnes (210 short tons) blue whale , which is the largest known animal that has ever lived. The sperm whale is the largest toothed predator on Earth. Several whale species exhibit sexual dimorphism , in that the females are larger than males. Baleen whales have no teeth; instead, they have plates of baleen, fringe-like structures that enable them to expel

5850-420: The 2.6-metre (8.5 ft) and 135-kilogram (298 lb) dwarf sperm whale to the 34-metre (112 ft) and 190-metric-ton (210-short-ton) blue whale. Overall, they tend to dwarf other cetartiodactyls; the blue whale is the largest creature on Earth. Several species have female-biased sexual dimorphism, with the females being larger than the males. One exception is with the sperm whale, which has males larger than

5967-483: The Congo , Uganda , Tanzania , and Kenya , north through to Ethiopia , Somalia , and Sudan , west to The Gambia , and south to South Africa . Genetic evidence suggests common hippos in Africa experienced a marked population expansion during or after the Pleistocene , attributed to an increase in water bodies at the end of the era. These findings have important conservation implications, as hippo populations across

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6084-454: The Cyprus dwarf hippo survived until the end of the Pleistocene or early Holocene. Evidence from the archaeological site Aetokremnos continues to cause debate on whether or not the species was driven to extinction or even encountered by humans. The hippopotamus is a megaherbivore and is exceeded in size among land animals only by elephants and some rhinoceros species. The mean adult weight

6201-752: The Elder , in his time, the best location in Egypt for capturing this animal was in the Saite nome ; the animal could still be found along the Damietta branch of the Nile after the Arab Conquest in 639. Reports of the slaughter of the last hippo in Natal Province were made at the end of the 19th century. Hippos are still found in the rivers and lakes of the northern Democratic Republic of

6318-550: The Inuit and the coastal peoples of Vietnam and Ghana, who sometimes hold whale funerals. Whales occasionally feature in literature and film. A famous example is the great white whale in Herman Melville 's novel Moby-Dick . Small whales, such as belugas , are sometimes kept in captivity and trained to perform tricks, but breeding success has been poor and the animals often die within a few months of capture. Whale watching has become

6435-750: The Netherlands, and western Germany during interglacial periods, such as the Last Interglacial (130–115,000 years ago). The youngest records of the species in Europe are from the Late Pleistocene of Greece, dating to around 40–30,000 years ago. Archaeological evidence exists of its presence in the Levant , dating to less than 3,000 years ago. The species was common in Egypt 's Nile region during antiquity , but it has since been driven out. According to Pliny

6552-479: The Upper West Region is agriculture . Crops grown include corn , millet , peanuts , okra , shea tree , and rice . Sheep , goats , chickens , pigs and guinea fowl are raised for meat and eggs. Because the region's dry season is long, extending roughly from October to May, many people leave the region to work in the southern part of Ghana for at least part of the year. -Basketball(Unicorns Basketball Team), Football,Tennis, Volleyball Some popular schools in

6669-666: The Yoruba. Hippo masks were also used in Nyau funerary rituals of the Chewa of Southern Africa. According to Robert Baden-Powell , Zulu warriors referred to hippos in war chants. The Behemoth from the Book of Job , 40:15–24 is thought to be based on the hippo. Hippos have been the subjects of various African folktales . According to a San story, when the Creator assigned each animal its place in nature,

6786-414: The animal's skin from cracking if it stays out of water too long. The testes of the males do not fully descend and a scrotum is not present. In addition, the penis retracts into the body when not erect . The genitals of the female hippos are unusual in that the vagina is ridged and the vulval vestibule has two large, protruding diverticula . Both of these have an unknown function. A hippo's lifespan

6903-447: The baleen whales (Mysticetes) and the toothed whales (Odontocetes). Whales have torpedo-shaped bodies with non-flexible necks, limbs modified into flippers, non-existent external ear flaps, a large tail fin, and flat heads (with the exception of monodontids and ziphiids ). Whale skulls have small eye orbits, long snouts (with the exception of monodontids and ziphiids) and eyes placed on the sides of its head. Whales range in size from

7020-475: The closest living relatives of cetaceans are the hippopotamuses ; these share a semi-aquatic ancestor that branched off from other artiodactyls some 60 mya. Around 40 mya, a common ancestor between the two branched off into cetacea and anthracotheres ; nearly all anthracotheres became extinct at the end of the Pleistocene 2.5 mya, eventually leaving only one surviving lineage – the hippopotamus. Whales split into two separate parvorders around 34 mya –

7137-690: The colder waters of the Northern and Southern Hemispheres and migrate to the equator to give birth. Species such as humpbacks and blue whales are capable of travelling thousands of miles without feeding. Males typically mate with multiple females every year, but females only mate every two to three years. Calves are typically born in the spring and summer; females bear all the responsibility for raising them. Mothers in some species fast and nurse their young for one to two years. Once relentlessly hunted for their products, whales are now protected by international law. The North Atlantic right whales nearly became extinct in

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7254-425: The completely aquatic cetaceans . The other branch became the anthracotheres , a large family of four-legged beasts, the earliest of which in the late Eocene would have resembled skinny hippos with comparatively smaller, narrower heads. All branches of the anthracotheres, except that which evolved into Hippopotamidae , became extinct during the Pliocene , leaving no descendants. A rough evolutionary lineage of

7371-404: The concentration of myoglobin than haemoglobin. Before going on long dives, many whales exhibit a behaviour known as sounding; they stay close to the surface for a series of short, shallow dives while building their oxygen reserves, and then make a sounding dive. The whale ear has specific adaptations to the marine environment. In humans, the middle ear works as an impedance equalizer between

7488-585: The continent are currently threatened by loss of access to fresh water. Hippos are also subject to unregulated hunting and poaching . The species is included in Appendix II of the Convention on International Trade in Endangered Species (CITES) meaning international export/import (including in parts and derivatives) requires CITES documentation to be obtained and presented to border authorities. As of 2017,

7605-613: The described morphological differences were small enough that they could have resulted from simple variation in nonrepresentative samples. A study examining mitochondrial DNA from skin biopsies taken from 13 sampling locations found "low, but significant, genetic differentiation" among H. a. amphibius , H. a. capensis , and H. a. kiboko . Neither H. a. tschadensis nor H. a. constrictus have been tested. Until 1909, naturalists classified hippos together with pigs based on molar patterns. Several lines of evidence, first from blood proteins, then from molecular systematics , DNA and

7722-553: The females. Odontocetes, such as the sperm whale, possess teeth with cementum cells overlying dentine cells. Unlike human teeth, which are composed mostly of enamel on the portion of the tooth outside of the gum, whale teeth have cementum outside the gum. Only in larger whales, where the cementum is worn away on the tip of the tooth, does enamel show. Mysticetes have large whalebone , as opposed to teeth, made of keratin. Mysticetes have two blowholes, whereas Odontocetes contain only one. Breathing involves expelling stale air from

7839-458: The god Set takes the form of a red hippopotamus and fights Horus for control of the land, but is defeated. The goddess Tawaret is depicted as a pregnant woman with a hippo head, representing fierce maternal love. The Ijaw people of the Niger Delta wore masks of aquatic animals like the hippo when practising their water spirit cults, and hippo ivory was used in the divination rituals of

7956-604: The ground) when they move fast enough. Hippos are reported to reach 30 km/h (19 mph) but this has not been confirmed. They are incapable of jumping but can walk up steep banks. The hippopotamus sleeps with both hemispheres of the brain resting, as in all land mammals, and usually sleeps on land or in water with the nostrils exposed. Despite this, it may be capable of sleeping while submerged, intermittently surfacing to breathe without waking. They appear to transition between different phases of sleep more quickly than other mammals. Because of their size and their habit of taking

8073-632: The hippo can thus be traced from Eocene and Oligocene species: from Anthracotherium and Elomeryx to the Miocene species Merycopotamus and Libycosaurus and finally the very latest anthracotheres in the Pliocene . These groups lived across Eurasia and Africa. The discovery of Epirigenys in East Africa, which was likely a descent of Asian anthracotheres and a sister taxon to Hippopotamidae, suggests that hippo ancestors entered Africa from Asia around 35 million years ago . An early hippopotamid

8190-729: The hippo had to jump into a nearby pool. The hippo lost most of his hair and was too embarrassed to leave the water. Hippopotamuses were rarely depicted in European art during the Renaissance and Baroque periods, due to less access to specimens by Europeans. One notable exception is Peter Paul Rubens ' The Hippopotamus and Crocodile Hunt (1615–1616). Ever since Obaysch inspired the "Hippopotamus Polka", hippos have been popular animals in Western culture for their rotund appearance, which many consider comical. The Disney film Fantasia featured

8307-565: The hippo in The Histories (written circa 440 BC) and the Roman naturalist Pliny the Elder wrote about the hippo in his encyclopedia Naturalis Historia (written circa 77 AD). The Yoruba people called the hippo erinmi , which means "elephant of the water". Some individual hippos have achieved international fame. Huberta became a celebrity during the Great Depression for trekking

8424-673: The hippopotamus is the next largest land mammal . It is also the largest extant land artiodactyl . Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, the closest living relatives of the hippopotamids are cetaceans ( whales , dolphins , porpoises , etc.), from which they diverged about 55 million years ago. Hippos are recognisable for their barrel-shaped torsos, wide-opening mouths with large canine tusks, nearly hairless bodies, pillar-like legs, and large size: adults average 1,500 kg (3,300 lb) for bulls (males) and 1,300 kg (2,900 lb) for cows (females). Despite its stocky shape and short legs, it

8541-404: The hippos wanted to live in the water, but were refused out of fear they might eat all the fish. After begging and pleading, the hippos were finally allowed to live in the water on the condition they would eat grass instead of fish, and fling their dung so it can be inspected for fish bones. In a Ndebele tale, the hippo originally had long, beautiful hair, but it was set on fire by a jealous hare and

8658-524: The huge mouthfuls of water they take in while retaining the krill and plankton they feed on. Because their heads are enormous—making up as much as 40% of their total body mass—and they have throat pleats that enable them to expand their mouths, they are able to take huge quantities of water into their mouth at a time. Baleen whales also have a well-developed sense of smell. Toothed whales, in contrast, have conical teeth adapted to catching fish or squid . They also have such keen hearing—whether above or below

8775-819: The infraorder Cetacea , i.e. all cetaceans apart from dolphins and porpoises . Dolphins and porpoises may be considered whales from a formal, cladistic perspective. Whales, dolphins and porpoises belong to the order Cetartiodactyla , which consists of even-toed ungulates . Their closest non-cetacean living relatives are the hippopotamuses , from which they and other cetaceans diverged about 54 million years ago. The two parvorders of whales, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have had their last common ancestor around 34 million years ago. Mysticetes include four extant (living) families : Balaenopteridae (the rorquals), Balaenidae (right whales), Cetotheriidae (the pygmy right whale), and Eschrichtiidae (the grey whale). Odontocetes include

8892-567: The intelligence of an animal. Since most of the brain is used for maintaining bodily functions, greater ratios of brain-to-body mass may increase the amount of brain mass available for more complex cognitive tasks. Allometric analysis indicates that mammalian brain size scales at approximately the ⅔ or ¾ exponent of the body mass. Comparison of a particular animal's brain size with the expected brain size based on such allometric analysis provides an encephalisation quotient that can be used as another indication of animal intelligence. Sperm whales have

9009-946: The largely terrestrial mammalian clade Laurasiatheria . Whales do not form a clade or order ; the infraorder Cetacea includes dolphins and porpoises , which are not considered whales in the informal sense. The phylogenetic tree shows the relationships of whales and other mammals, with whale groups marked in green. ( carnivorans and allies) [REDACTED] ( horses , rhinos , tapirs ) [REDACTED] ( camels, llamas ) [REDACTED] ( pigs, hogs, peccaries ) [REDACTED] ( cattle , sheep , antelopes ) [REDACTED]  ( hippos ) [REDACTED] ( † Ambulocetus , † Protocetus , † Basilosaurus ) ( right whales , grey whales , rorquals ) ( dolphins , porpoises , beluga whales , narwhals ) ( river dolphins ) ( sperm whales ) ( beaked whales ) Cetaceans are divided into two parvorders. The larger parvorder, Mysticeti (baleen whales),

9126-399: The largest and smallest odontocetes, and spend a large portion of their life hunting squid. P. macrocephalus spends most of its life in search of squid in the depths; these animals do not require any degree of light at all, in fact, blind sperm whales have been caught in perfect health. The behaviour of Kogiids remains largely unknown, but, due to their small lungs, they are thought to hunt in

9243-549: The modern H. amphibius date to the Middle Pleistocene , though there are possible Early Pleistocene records. Three species of Malagasy hippopotamus became extinct during the Holocene on Madagascar , the last of them within the past 1,000 years. The Malagasy hippos were smaller than the modern hippo, a likely result of the process of insular dwarfism . Fossil evidence indicates many Malagasy hippos were hunted by humans,

9360-517: The nearsightedness that results from the refraction of light; they contain both rod and cone cells, meaning they can see in both dim and bright light, but they have far more rod cells than they do cone cells. Whales do, however, lack short wavelength sensitive visual pigments in their cone cells indicating a more limited capacity for colour vision than most mammals. Most whales have slightly flattened eyeballs, enlarged pupils (which shrink as they surface to prevent damage), slightly flattened corneas and

9477-440: The neck vertebrae, while increasing stability when swimming at high speeds, decreases flexibility; whales are unable to turn their heads. When swimming, whales rely on their tail fin to propel them through the water. Flipper movement is continuous. Whales swim by moving their tail fin and lower body up and down, propelling themselves through vertical movement, while their flippers are mainly used for steering. Some species log out of

9594-493: The nictitating membrane. It is the only monogenean species (which normally live on fish) documented to live on a mammal. Cut marks on bones of H. amphibius found at Bolomor Cave , a site in Spain preserving fossils dating from 230,000 to 120,000 years ago, provides evidence for Neanderthal butchery of hippopotamuses. The earliest evidence of modern human interaction with hippos comes from butchery cut marks on hippo bones found at

9711-568: The opportunity arises, and humans may come into conflict with them on these occasions. These encounters can be fatal to either humans or hippos. According to the Ptolemaic historian Manetho , the pharaoh Menes was carried off and then killed by a hippopotamus. Hippos have long been popular zoo animals. The first record of hippos taken into captivity for display is dated to 3500 BC in Hierakonpolis, Egypt. The first zoo hippo in modern history

9828-531: The origins of Hippopotamidae suggests hippos and whales shared a common semiaquatic ancestor that branched off from other artiodactyls around 60 million years ago . This hypothesised ancestral group likely split into two branches again around 54 million years ago . One branch would evolve into cetaceans , possibly beginning about 52 million years ago , with the protowhale Pakicetus and other early whale ancestors collectively known as Archaeoceti . This group eventually underwent aquatic adaptation into

9945-417: The outside air's low impedance and the cochlear fluid's high impedance. In whales, and other marine mammals, there is no great difference between the outer and inner environments. Instead of sound passing through the outer ear to the middle ear, whales receive sound through the throat, from which it passes through a low-impedance fat-filled cavity to the inner ear. The whale ear is acoustically isolated from

10062-567: The population should be eradicated, as they are breeding rapidly and are an increasing menace to humans and the environment. Attempts to control them include sterilisation and culling . Hippos are semiaquatic and require enough water to immerse in, while being close to grass. They mostly live in freshwater habitat, but can be found in estuaries . They prefer relatively still waters with gently sloping shores, though male hippos may also be found in very small numbers in more rapid waters with rocky slopes. Like most herbivores, hippos will consume

10179-440: The pulsed calls of belugas. Pulses in a click train are emitted at intervals of ≈35–50 milliseconds , and in general these inter-click intervals are slightly greater than the round-trip time of sound to the target. Whistles are narrow-band frequency modulated (FM) signals, used for communicative purposes, such as contact calls. Whales are known to teach, learn, cooperate, scheme, and grieve. The neocortex of many species of whale

10296-419: The region include: The political administration of the region is through the local government system. Under this administration system, the region is divided into 11 MMDA's (made up of 0 Metropolitan, 5 Municipal and 6 Ordinary Assemblies). Each District, Municipal or Metropolitan Assembly, is administered by a Chief Executive, representing the central government but deriving authority from an Assembly headed by

10413-699: The region's neighbours also pose a threat. The Wechiau Hippopotamus Sanctuary is located southwest of Wa, along the Black Volta River in the Wa West District. The Gwollu Wall in the Sissala District serves as the hometown of one of Ghana's past presidents - Dr. Hilla Limann . The staple food of the people of the Upper West Region is sao or Tuo Zaafi in the local dialect, which is often abbreviated TZ or T-Zed in English. The major economic activity of

10530-464: The right whales. These animals have very large heads, which can make up as much as 40% of their body mass, and much of the head is the mouth. This allows them to take in large amounts of water into their mouths, letting them feed more effectively. Eschrichtiids have one living member: the grey whale. They are bottom feeders, mainly eating crustaceans and benthic invertebrates. They feed by turning on their sides and taking in water mixed with sediment, which

10647-610: The river ' . In English, the plural is "hippopotamuses". The modern hippopotamus and the pygmy hippopotamus are the only living members of the family Hippopotamidae. Some taxonomists place hippos and anthracotheres in the superfamily Anthracotheroidea. Hippopotamidae are classified along with other even-toed ungulates in the order Artiodactyla . Five subspecies of hippos have been described based on morphological differences in their skulls as well as differences in geographical range: The suggested subspecies above were never widely used or validated by field biologists;

10764-419: The roof of their skulls. This allows these organs to remain above the surface while the rest of the body is submerged. The nostrils and ears can close when underwater while nictitating membranes cover the eyes. The vocal folds of the hippo are more horizontally positioned, much like baleen whales. Underneath are throat tissues, where vibrations are transmitted to produce underwater calls. The hippo's jaw

10881-432: The same paths to feed, hippos can have a significant impact on the land across which they walk, keeping the land clear of vegetation and depressing the ground. Over prolonged periods, hippos can divert the paths of swamps and channels. By defecating in the water, the animals also appear to pass on microbes from their gut, affecting the biogeochemical cycle . On occasion, hippos have been filmed eating carrion , usually near

10998-457: The secretions; one red hipposudoric acid and one orange norhipposudoric acid, which inhibit the growth of disease-causing bacteria and their light-absorption profile peaks in the ultraviolet range, creating a sunscreen effect. Regardless of diet, all hippos secrete these pigments so food does not appear to be their source; rather, they may be synthesised from precursors such as the amino acid tyrosine . This natural sunscreen cannot prevent

11115-549: The sensation of taste. Whale vocalization is likely to serve several purposes. Some species, such as the humpback whale, communicate using melodic sounds, known as whale song . These sounds may be extremely loud, depending on the species. Humpback whales only have been heard making clicks, while toothed whales use sonar that may generate up to 20,000 watts of sound (+73  dBm or +43  dBw ) and be heard for many miles. Captive whales have occasionally been known to mimic human speech. Scientists have suggested this indicates

11232-480: The shoulder, with males and females ranging 1.40 to 1.65 m (4 ft 7 in to 5 ft 5 in) and 1.30 to 1.45 m (4 ft 3 in to 4 ft 9 in) tall at the shoulder respectively. The species has a typical head–body length of 3.3–3.45 m (10.8–11.3 ft) and an average standing height of 1.4 m (4 ft 7 in) at the shoulder. Hippos have barrel-shaped bodies with short tails and legs, and an hourglass-shaped skull with

11349-515: The shrinking and eventual disappearance of the hind limbs (the first odontocetes and mysticetes 34 mya). Whale morphology shows several examples of convergent evolution , the most obvious being the streamlined fish-like body shape. Other examples include the use of echolocation for hunting in low light conditions — which is the same hearing adaptation used by bats  — and, in the rorqual whales, jaw adaptations, similar to those found in pelicans , that enable engulfment feeding. Today,

11466-400: The skull by air-filled sinus pockets, which allow for greater directional hearing underwater. Odontocetes send out high-frequency clicks from an organ known as a melon . This melon consists of fat, and the skull of any such creature containing a melon will have a large depression. The melon size varies between species, the bigger the more dependent they are on it. A beaked whale for example has

11583-432: The smaller upper canines. The canines and incisors are used mainly for combat instead of feeding. Hippos rely on their flattened, horny lips to grasp and pull grasses which are then ground by the molars . The hippo is considered to be a pseudoruminant ; it has a complex three-chambered stomach, but does not "chew cud ". Hippo skin is 6 cm (2.4 in) thick across much of its body with little hair. The animal

11700-576: The south by the Northern region, on the west by western Ghana-Burkina Faso, and the Upper West region on the north. It is the seventh largest region in Ghana in total area, and it is made up of 11 districts. By virtue of its location, the Upper West Region has the potential for international and inter-regional trade and other bilateral relations, but the overspill of criminal activities and disasters, such as bushfires, diseases and pestilence, armed robbery, etc., from

11817-429: The sperm whale and bowhead whale, possess discrete rudimentary appendages, which may contain feet and digits. Whales are fast swimmers in comparison to seals, which typically cruise at 5–15 kn, or 9–28 kilometres per hour (5.6–17.4 mph); the fin whale, in comparison, can travel at speeds up to 47 kilometres per hour (29 mph) and the sperm whale can reach speeds of 35 kilometres per hour (22 mph). The fusing of

11934-526: The surface of the water—that some can survive even if they are blind. Some species, such as sperm whales, are particularly well adapted for diving to great depths to catch squid and other favoured prey. Whales evolved from land-living mammals, and must regularly surface to breathe air, although they can remain underwater for long periods of time. Some species, such as the sperm whale , can stay underwater for up to 90 minutes. They have blowholes (modified nostrils) located on top of their heads, through which air

12051-563: The twentieth century, with a population low of 450, and the North Pacific grey whale population is ranked Critically Endangered by the IUCN . Besides the threat from whalers, they also face threats from bycatch and marine pollution. The meat, blubber and baleen of whales have traditionally been used by indigenous peoples of the Arctic. Whales have been depicted in various cultures worldwide, notably by

12168-467: The unique ability to hold their heads partially above the water and send out a cry that travels through both water and air; individuals respond both above and below water. Cows reach sexual maturity at five to six years of age and have a gestation period of eight months. A study of endocrine systems revealed cows may begin puberty at as early as three or four years. Bulls reach maturity at around 7.5 years. Both conceptions and births are highest during

12285-466: The water and grazing areas. "Yawning" serves as a threat display. When fighting, bulls use their incisors to block each other's attacks and their large canines as offensive weapons. When hippos become over-populated or a habitat shrinks, bulls sometimes attempt infanticide , but this behaviour is not common under normal conditions. The most common hippo vocalisation is the "wheeze honk", which can travel over long distances in air. This call starts as

12402-423: The water dries up. The bull has breeding access to all the cows in his territory. Younger bachelors are allowed to stay as long as they defer to him. A younger male may challenge the old bull for control of the territory. Within the pods, the hippos tend to segregate by sex and status. Bachelor males lounge near other bachelors, females with other females, and the territorial male is on his own. When hippos emerge from

12519-409: The water to graze, they do so individually. Hippos engage in "muck-spreading" which involves defecating while spinning their tails to distribute the faeces over a greater area. Muck-spreading occurs both on land and in water and its function is not well understood. It is unlikely to serve a territorial function, as the animals only establish territories in the water. They may be used as trails between

12636-537: The water, grazing is a solitary activity and hippos typically do not display territorial behaviour on land. Hippos are among the most dangerous animals in the world due to their aggressive and unpredictable nature. They are threatened by habitat loss and poaching for their meat and ivory (canine teeth). The Latin word hippopotamus is derived from the ancient Greek ἱπποπόταμος ( hippopótamos ), from ἵππος ( híppos ) ' horse ' and ποταμός ( potamós ) ' river ' , together meaning ' horse of

12753-461: The water, which may allow them to travel faster. Their skeletal anatomy allows them to be fast swimmers. Most species have a dorsal fin . Whales are adapted for diving to great depths. In addition to their streamlined bodies, they can slow their heart rate to conserve oxygen; blood is rerouted from tissue tolerant of water pressure to the heart and brain among other organs; haemoglobin and myoglobin store oxygen in body tissue; and they have twice

12870-454: The water. Despite being semiaquatic, an adult hippo is not a particularly good swimmer, nor can it float. It rarely enters deep water; when it does, the animal moves by bouncing off the bottom. An adult hippo surfaces every four to six minutes, while young need to breathe every two to three minutes. Hippos move on land by trotting , and limb movements do not change between speeds. They can reach an airborne stage (a stage when all limb are off

12987-728: The water. There are other reports of meat-eating and even cannibalism and predation . Hippos' stomach anatomy lacks adaptions to carnivory and meat-eating is likely caused by lack of nutrients or just an abnormal behaviour. It is challenging to study the interaction of bulls and cows because hippos are not sexually dimorphic , so cows and young bulls are almost indistinguishable in the field. Hippo pods fluctuate but can contain over 100 hippos. Although they lie close together, adults develop almost no social bonds. Males establish territories in water but not land, and these may range 250–500 m (820–1,640 ft) in lakes and 50–100 m (160–330 ft) in rivers. Territories are abandoned when

13104-478: The water. Upon striking an object in the water, the sound waves bounce back at the whale. These vibrations are received through fatty tissues in the jaw, which is then rerouted into the ear-bone and into the brain where the vibrations are interpreted. All toothed whales are opportunistic, meaning they will eat anything they can fit in their throat because they are unable to chew. These animals rely on their well-developed flippers and tail fin to propel themselves through

13221-488: The water; they swim by moving their fore-flippers and tail fin up and down. Whale ribs loosely articulate with their thoracic vertebrae at the proximal end, but do not form a rigid rib cage. This adaptation allows the chest to compress during deep dives as the pressure increases. Mysticetes consist of four families: rorquals (balaenopterids) , cetotheriids , right whales (balaenids) , and grey whales (eschrichtiids) . The main difference between each family of mysticete

13338-672: The water; they swim by moving their fore-flippers and tail fin up and down. Whale ribs loosely articulate with their thoracic vertebrae at the proximal end, but they do not form a rigid rib cage. This adaptation allows the chest to compress during deep dives as opposed to resisting the force of water pressure. Excluding dolphins and porpoises, odontocetes consist of four families: belugas and narwhals (monodontids) , sperm whales (physeterids) , dwarf and pygmy sperm whales (kogiids) , and beaked whales (ziphiids) . The differences between families of odontocetes include size, feeding adaptations and distribution. Monodontids consist of two species:

13455-537: The whales' closest terrestrial living relatives. Mysticetes are also known as baleen whales. They have a pair of blowholes side by side and lack teeth; instead they have baleen plates which form a sieve-like structure in the upper jaw made of keratin, which they use to filter plankton from the water. Some whales, such as the humpback, reside in the polar regions where they feed on a reliable source of schooling fish and krill . These animals rely on their well-developed flippers and tail fin to propel themselves through

13572-515: Was Obaysch , who arrived at the London Zoo on 25 May 1850, where he attracted up to 10,000 visitors a day and inspired a popular song, the "Hippopotamus Polka". Hippos generally breed well in captivity; birth rates are lower than in the wild, but this can be attributed to zoos' desire to limit births, since hippos are relatively expensive to maintain. Starting in 2015, the Cincinnati Zoo built

13689-413: Was recorded protecting a calf's carcass after it had died. Calves may be temporarily kept in nurseries , guarded by one or more adults, and will play amongst themselves. Like many other large mammals, hippos are described as K-strategists , in this case typically producing just one large, well-developed infant every couple of years (rather than many small, poorly developed young several times per year, as

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