99-418: The lowland nyala or simply nyala ( Tragelaphus angasii ) is a spiral-horned artiodactyl antelope native to Southern Africa . The species is part of the family Bovidae and the genus Tragelaphus (formerly placed in the genus Nyala ). It was first described in 1849 by George French Angas and exhibits the highest sexual dimorphism among the spiral-horned antelopes. It is not to be confused with
198-414: A Cooperia rotundispiculum race, Gaigeria pachyscelis , a Gongylonema species, Haemonchus vegliai , Impalaia tuberculata , an Oesophagostomum species, a Setaria species, Trichostrongylus deflexus , Trichostrongylus falculatus , the larval stage of a Taenia species, a Thysaniezia species and Schistosoma mattheei . Ostertagia harrisi and C. rotundispiculum were
297-695: A mitochondrial analysis of the nine Tragelaphus species. mtDNA and nDNA data were compared. The results showed that sitatunga plus bongo ( T. eurycerus ) form a monophyletic clade with the mountain nyala ( T. buxtoni ) and bushbuck ( T. scriptus ). The greater kudu ( T. strepsiceros ) split from this clade approximately 8.6 million years ago. Within Tragelaphus , the bushbuck, bongo, sitatunga and nyala ( T. angasii ) are particularly close relatives. The bushbuck and sitatunga are genetically similar enough to hybridise . Hybrids between bongo and sitatunga have proved to be fertile. The sitatunga
396-476: A trypanosome was isolated from a nyala, wild-caught in Mozambique, which was diagnosed and found as akin to Trypanosoma vivax , based on biological, morphological and molecular data. The nyala can also suffer from myopathy . In between January 1973 and June 1981, 21 nyalas succumbed to the disease. The main symptoms were stiffness, inability to rise, and failure to suckle in newborns. Necrosis (that is,
495-399: A 40–55 cm (16–22 in) long bushy tail white underside. Both sexes have a dorsal crest of hair running right from the back of the head to the end of the tail. Males have another line of hair along the midline of their chest and belly. Only the males have horns. Horns are 60–83 cm (24–33 in) long and yellow-tipped. There are one or two twists. The spoor is similar to that of
594-645: A few bumps. In contrast, camels and ruminants have bumps that are crescent-shaped cusps ( selenodont ). Sitatunga The sitatunga ( Tragelaphus spekii ) or marshbuck is a swamp -dwelling medium-sized antelope found throughout central Africa , centering on the Democratic Republic of the Congo , the Republic of the Congo , Cameroon , parts of Southern Sudan , Equatorial Guinea , Burundi , Ghana , Botswana , Rwanda , Zambia , Gabon ,
693-407: A greater average height whereas females fed from the low herbaceous layer . It was concluded that the differences resulted from varying nutritional and energetic demands according to their diverse body sizes and differing reproductive strategies. The nyala breeds throughout the year, but mating peaks in spring and autumn. The reason for this is still unknown, but attributed to the photoperiod and
792-470: A group of danger. This feature is mainly used by females. They also react to the alarm calls of impala , baboon and kudu. The impala has been found to react to the calls of the nyala as well. The main predators of nyala are lion , leopard , cheetah , spotted hyena , African wild dog and nile crocodile while baboons and raptorial birds are predators of juveniles. As a herbivore , the nyala's diet consists of foliage, fruits, flowers and twigs. During
891-538: A large part of this time feeding. Basically sedentary, they rest in flat areas and reed beds , especially during the hotter part of the day. They seldom leave their swamp habitat during the daytime. Though sitatunga commonly form pairs or remain solitary, larger groups have also been observed. A study in Kenya recorded a herd of as many as nine individuals, comprising an adult male, four females and four juveniles. Loose groups may be formed but interaction among individuals
990-561: A louse fly species were recovered in a study of 73 nyalas at Umfolozi, Mkuzi and Ndumu Game Reserves in northeastern KwaZulu-Natal in 1983 and 1984 and an additional six individuals in 1994. It was found that nyalas were hosts to all stages of development in Boophilus decoloratus , Rhipicephalus appendiculatus and R. muehlensi and the immature stages of Amblyomma hebraeum and Rhipicephalus maculatus . Adult males served hosts to more ticks and lice than adult females did. Also,
1089-403: A rough and scraggy mane, usually brown in colour, and a white dorsal stripe. There is a chevron between the eyes of the males. The body and legs of this antelope are specially adapted to its swampy habitat. The hooves of the male are elongated and widely splayed. The rubbery, shaggy, water-repellent coat is minimally affected by slimy and muddy vegetation. The wedge-like shape and lowering of
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#17327753038291188-576: A similar aquatic lifestyle. Hippopotamuses appeared in the late Miocene and occupied Africa and Asia—they never got to the Americas. The camels ( Tylopoda ) were, during large parts of the Cenozoic , limited to North America; early forms like Cainotheriidae occupied Europe. Among the North American camels were groups like the stocky, short-legged Merycoidodontidae . They first appeared in
1287-477: A simple stomach that digests food. Thus, they were grouped together as non-ruminants (Porcine). All other even-toed ungulates have molars with a selenodont construction (crescent-shaped cusps) and have the ability to ruminate , which requires regurgitating food and re-chewing it. Differences in stomach construction indicated that rumination evolved independently between tylopods and ruminants ; therefore, tylopods were excluded from Ruminantia . The taxonomy that
1386-474: A slim build, lanky legs, and a long tail. Their hind legs were much longer than their front legs. The early to middle Eocene saw the emergence of the ancestors of most of today's mammals. Two formerly widespread, but now extinct, families of even-toed ungulates were Entelodontidae and Anthracotheriidae . Entelodonts existed from the middle Eocene to the early Miocene in Eurasia and North America. They had
1485-473: A stocky body with short legs and a massive head, which was characterized by two humps on the lower jaw bone. Anthracotheres had a large, porcine ( pig -like) build, with short legs and an elongated muzzle . This group appeared in the middle Eocene up until the Pliocene , and spread throughout Eurasia, Africa, and North America. Anthracotheres are thought to be the ancestors of hippos, and, likewise, probably led
1584-424: A very flexible body, contributing to their speed by increasing their stride length. Many even-toed ungulates have a relatively large head. The skull is elongated and rather narrow; the frontal bone is enlarged near the back and displaces the parietal bone , which forms only part of the side of the cranium (especially in ruminants). Four families of even-toed ungulates have cranial appendages. These Pecora (with
1683-470: Is Tragelaphus angasii . The name angasii is attributed to Angas, who said that John Edward Gray had named this species after Angas' father, George Fife Angas of South Australia. According to Article 50.1.1 of the International Code of Zoological Nomenclature and International Commission on Zoological Nomenclature , though, this is insufficient to state Gray as the author. The name "nyala"
1782-422: Is 14–37 cm (5.5–14.6 in) long. The saucer-shaped ears are 11–17 cm (4.3–6.7 in) long. Only the males possess horns; these are spiral in shape, have one or two twists and are 45–92 cm (18–36 in) long. The sitatunga is almost indistinguishable from the nyala , except in pelage and spoor . Speke pointed out that, though "closely allied" to the waterbuck, the sitatunga lacks stripes and
1881-477: Is a medium-sized antelope. It is sexually dimorphic , with males considerably larger than females. The head-and-body length is typically between 136–177 cm (54–70 in) in males and 104–146 cm (41–57 in) in females. Males reach approximately 81–116 cm (32–46 in) at the shoulder, while females reach 72–90 cm (28–35 in). Males typically weigh 76–119 kg (168–262 lb), while females weigh 24–57 kg (53–126 lb). The tail
1980-425: Is born. Parturition occurs throughout the year, though a peak may occur in the dry season. Calves are hidden adroitly, and brought out of cover only in the presence of many other sitatunga. The mother gazes and nods at the calf to summon it for nursing. A calf follows its mother about even after she has given birth to another calf. The mother suckles and licks her calf for about six months. The calf takes time to master
2079-569: Is extinct in Niger , where it formerly occurred in the Lake Chad region, and is feared to be extinct in Togo , where its habitat has been taken over by dense human settlements. While it is localised and sporadic in western Africa, the sitatunga is still common in the forests of central Africa and certain swampy regions in central, eastern and southern Africa. Habitat loss is the most severe threat to
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#17327753038292178-475: Is more adapted to a squeezing mastication , which is characteristic of omnivores . Camels and ruminants have fewer teeth; there is often a yawning diastema , a designated gap in the teeth where the molars are aligned for crushing plant matter. The incisors are often reduced in ruminants, and are completely absent in the upper jaw . The canines are enlarged and tusk-like in the Suina, and are used for digging in
2277-476: Is more variable in its general characters than any other member of the tribe Strepsicerotini , that consists of the genera Taurotragus (elands) and Tragelaphus , probably because of their confinement to swampy and marshy habitats. On the basis of physical characteristics such as hair texture, coat colour and the coat stripes, up to ten subspecies of the sitatunga have been described. However, these factors may not be reliable since hair texture could vary with
2376-501: Is referred to as the binomial authority . Speke had stated in a footnote in his book that the species had been named Tragelaphus spekii by English zoologist Philip Sclater . However, according to the International Code of Zoological Nomenclature (Article 50.1.1) and the International Commission on Zoological Nomenclature , that acknowledge the person who first described the species, simply declaring Sclater as
2475-455: Is spotted instead. The coat colour varies geographically, but, in general, is a rufous red in juveniles and chestnut in females. There are white facial markings, as well as several stripes and spots all over, though they are only faintly visible. White patches can be seen on the throat, near the head and the chest. A pair of inguinal scent glands are present. The coats of males darken with age, becoming gray to dark brown. Males develop
2574-672: Is the Tsonga name for this antelope, which is likely the source of the English, along with Zulu inyala . Its first known use was in 1899. The word has a Bantu origin, similar to the Venda word dzì-nyálà (nyala buck). The nyala is the second taxon to branch off from the tragelaphine family tree just after the lesser kudu . As the nyala line has remained separate for a considerable time (over 5 million years), some authorities have placed it in its own monotypic genus Nyala . Nyala
2673-708: Is therefore focused on anthracotheres (family Anthracotheriidae); one dating from the Eocene to Miocene was declared to be "hippo-like" upon discovery in the 19th century. A study from 2005 showed that the anthracotheres and hippopotamuses had very similar skulls , but differed in the adaptations of their teeth. It was nevertheless believed that cetaceans and anthracothereres descended from a common ancestor, and that hippopotamuses developed from anthracotheres. A study published in 2015 confirmed this, but also revealed that hippopotamuses were derived from older anthracotherians. The newly introduced genus Epirigenys from Eastern Africa
2772-525: Is thus the sister group of hippos. Linnaeus postulated a close relationship between camels and ruminants as early as the mid-1700s. Henri de Blainville recognized the similar anatomy of the limbs of pigs and hippos, and British zoologist Richard Owen coined the term "even-toed ungulates" and the scientific name "Artiodactyla" in 1848. Internal morphology (mainly the stomach and the molars) were used for classification. Suines (including pigs ) and hippopotamuses have molars with well-developed roots and
2871-486: Is very low. Individuals generally associate only with their own sex. The sitatunga is not territorial . Males may engage in locking horns with other males and attacking vegetation using their horns. They may perform feinting by raising their forelegs with the hindlegs rooted in the ground as a threat display . Sitatunga interact with each other by first touching their noses, which may be followed by licking each other and nibbling. Alarmed animals may stand motionless, with
2970-790: The Abuko Nature Reserve . On the other hand, though the animal is hunted by locals primarily for food, Botswana still supports a large portion of the total population. The species is of great economic significance for northern Botswana, that produces some of the world's biggest sitatunga trophies . Its status is unclear in Chad, Ghana, Guinea, Burundi and Mozambique and Zimbabwe. Significant populations still exist in countries such as Cameroon, Central African Republic, The Democratic Republic of Congo, Equatorial Guinea, Gabon, Tanzania and Zambia. The inaccessibility of its habitat has rendered population estimates very difficult. In 1999, Rod East of
3069-523: The Central African Republic , Tanzania , Uganda and Kenya . The sitatunga is mostly confined to swampy and marshy habitats. Here they occur in tall and dense vegetation as well as seasonal swamps, marshy clearings in forests, riparian thickets and mangrove swamps. The scientific name of the sitatunga is Tragelaphus spekii . The species was first described by the English explorer John Hanning Speke in 1863. Speke first observed
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3168-625: The Least Concern category by the International Union for Conservation of Nature and Natural Resources ( IUCN ), and under Appendix III (Ghana) of the Washington Convention (CITES). In Senegal, intensive hunting for meat and habitat degradation have made the sitatunga very rare. Formerly it was common throughout Gambia, but now it is confined to a few inaccessible swamps; a population has been introduced in
3267-1040: The Ndumo Game Reserve , uMkuze Game Reserve and Hluhluwe-Umfolozi Game Reserve , all in KwaZulu-Natal , as well as in Kruger National Park . As of 1999, 10–15% of nyala occurred on private land. Efforts are being made to retain the populations of nyala in Gorongosa National Park and Banhine National Park in Mozambique. Nyala also thrive in Lengwe National Park in Malawi. Nyala have never been observed showing territoriality . Territories of either sex overlap extensively. The home ranges of males are approximately equal to that of females, about 10 square kilometres (3.9 sq mi) in area. The major threats to
3366-618: The Nile lechwe in the Sudd swamps and with the southern lechwe in Angola , Botswana and Zambia . The sitatunga is native to Angola, Benin , Botswana, Burundi , Cameroon , Central African Republic , Chad , The Democratic Republic of the Congo , Equatorial Guinea , Gabon , Gambia , Ghana , Guinea , Guinea-Bissau , Kenya , Mozambique , Namibia , Nigeria , Rwanda , Senegal , South Sudan , Tanzania , Uganda , Zambia and Zimbabwe . It
3465-694: The Old World , exist today only in the Americas . South America was settled by even-toed ungulates only in the Pliocene, after the land bridge at the Isthmus of Panama formed some three million years ago. With only the peccaries, lamoids (or llamas ), and various species of capreoline deer , South America has comparatively fewer artiodactyl families than other continents, except Australia, which has no native species. The classification of artiodactyls
3564-401: The bushbuck , the large common and giant elands , the greater and lesser kudus , the mountain nyala (of Ethiopia ) and the swamp-dwelling sitatunga , all of which share similar characteristics, such as hornless females, vertical side-stripes and other unique white markings, and the spiraling horns and distinct "beard" or dewlap of males, often with a raised trail of fur extending down
3663-507: The hind legs have a reduction in the number of toes to three. The central axis of the leg is between the third and fourth toe. The first toe is missing in modern artiodactyls, and can only be found in now-extinct genera. The second and fifth toes are adapted differently between species: When camels have only two toes present, the claws are transformed into nails (while both are made of keratin , claws are curved and pointed while nails are flat and dull). These claws consist of three parts:
3762-412: The ruminants as the sister group of cetaceans. Subsequent studies established the close relationship between hippopotamuses and cetaceans; these studies were based on casein genes , SINEs , fibrinogen sequences, cytochrome and rRNA sequences, IRBP (and vWF ) gene sequences, adrenergic receptors , and apolipoproteins . In 2001, the fossil limbs of a Pakicetus (amphibioid cetacean
3861-487: The 14th chromosome, as in other tragelaphids , but no inversion of the Y chromosome occurs. Cranial studies have shown that the mountain nyala and nyala, though sharing a common name, are actually distant relatives. Fossil evidence suggests that the nyala has been a separate species since the end of the Miocene (5.8 million years ago). Genetic evidence suggests that the proto-nyala had some early hybridization with
3960-524: The British Isles", it was noted that spongiform encephalopathy had been diagnosed in one nyala captive in a zoo. The nyala was formerly affected by the disease rinderpest , although the viral disease is considered eradicated now. The nyala is active mainly in the early morning and late afternoon. It browses during the day if temperatures are 20–30 °C (68–86 °F) and during the night in rainy season. These antelopes rest in thick bushes during
4059-999: The IUCN SSC Antelope Specialist Group estimated a total population of 170,000, but this is likely to be an overestimate. Its numbers are decreasing in areas of heavy human settlement, but are stable elsewhere. Around 40 percent of the populations (based on the overestimate of 170,000) occurs in protected areas, mainly in Okavango Delta and Linyanti and Chobe swamps (Botswana); Dja Faunal Reserve and Lobéké National Park (Cameroon); Bangassou (Central African Republic); Odzala National Park , Lake Télé Community Reserve , Likouala and Salonga National Park (The Democratic Republic of Congo); Monte Alén National Park (Equatorial Guinea); Saiwa Swamp National Park (Kenya); Akagera National Park (Rwanda); Moyowosi and Kigosi Game Reserves (Tanzania); Bangweulu and Busanga Swamps (Zambia). However, only
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4158-460: The KFI, the kidney is removed and weighed with the fat and once again excluding the fat. The resultant difference is the amount of fat on the kidney. The more the fat, the healthier the animal. In rut , male nyalas had lower KFIs, which did not vary much with the season. Pregnant females of both nyala and impala had higher KFIs than non-pregnant ones. There is a significant increase in corpus luteum in
4257-553: The authority in a footnote is insufficient to recognise him as the author. Hence, Speke was recognised as the correct authority and T. spekii (where spekii is the genitive of the Latinised "Spekius") was considered the correct name for the species. The sitatunga is placed under the genus Tragelaphus and in the family Bovidae . In 2005, Sandi Willows-Munro of the University of KwaZulu-Natal ( Durban ) carried out
4356-403: The back and underside. In 2005, Sandi Willows-Munro (of the University of KwaZulu-Natal ) and colleagues carried out a mitochondrial DNA analysis of the nine Tragelaphus species. Mitochondrial DNA and nuclear DNA data were compared. The results showed the tribe Tragelaphini to be monophyletic , with the lesser kudu ( T. imberbis ) basal in the phylogeny, followed by the nyala. On
4455-410: The basis of mitochondrial data, studies have estimated that the lesser kudu separated from its sister clade around 13.7 million years ago. However, nuclear DNA data shows lesser kudu and nyala forming a clade, which collectively separated from the sister clade 13.8 million years ago. The nyala has 55 male chromosomes and 56 female chromosomes. The Y chromosome has been translocated onto
4554-486: The bushbuck, but larger. It is 5–6 cm (2.0–2.4 in) long. The feces resemble round to spherical pellets. The nyala has hairy glands on its feet, which leave their scent wherever it walks. The condition of the nyala often varies between the sexes. According to a study, this can be attributed to the differences in their body sizes. It was noted that during nutritional stress, old adults died in more numbers, of which most were males. During an attempt of blood sampling in
4653-496: The climate, while pelage colour and markings vary greatly among individuals. Moreover, the coat might darken and the stripes and spots on it might fade with age, especially in males. The species might even be monotypic , however, based on different drainage systems , three distinct subspecies are currently recognised: Giant eland Common eland Greater kudu Balbok Bongo Sitatunga Cape bushbuck Harnessed bushbuck Nyala Lesser kudu The sitatunga
4752-451: The coat provides an excellent camouflage. Hearing is acute, and the ears are so structured that the animal can accurately determine the direction from where a sound has originated. This adaptation is of profound use in habitats where long sight is of very little value due to the density and darkness of the environment. Sitatunga are active mainly during the early hours after dawn, the last one or two hours before dusk, and at night, and spend
4851-418: The dietary habits of the impala and the nyala showed that the amount of dicotyledons in their diets varied seasonally. In the dry season, the nyala's dicotyledon diet content was 83.2% and the impala's 52%. In this season, the diet grew richer in fiber and dietary proteins were less. The reverse occurred in the rainy season. As the rainy season arrived, both species took to a diet of mainly monocotyledons , and
4950-462: The early Eocene (about 53 million years ago). Since these findings almost simultaneously appeared in Europe , Asia , and North America , it is very difficult to accurately determine the origin of artiodactyls. The fossils are classified as belonging to the family Diacodexeidae ; their best-known and best-preserved member is Diacodexis . These were small animals, some as small as a hare , with
5049-609: The early Cenozoic ( Paleocene and Eocene ), which had hooves instead of claws on their feet. Their molars were adapted to a carnivorous diet, resembling the teeth in modern toothed whales , and, unlike other mammals, had a uniform construction. The suspected relations can be shown as follows: Artiodactyla [REDACTED] Mesonychia † [REDACTED] Cetacea [REDACTED] Molecular findings and morphological indications suggest that artiodactyls, as traditionally defined, are paraphyletic with respect to cetaceans. Cetaceans are deeply nested within
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#17327753038295148-955: The endangered mountain nyala living in the Bale region of Ethiopia. The nyala's range encompasses much of Southern Africa . As its population is relatively stable, it has been listed as of least concern by the International Union for Conservation of Nature . It generally browses during the day in warm weather and during the night in the rainy season. As a herbivore, the nyala feeds upon foliage, fruits and grasses, and requires sufficient fresh water. A shy animal, it prefers water holes rather than open spaces. The nyala does not show signs of territoriality, and individuals' areas can overlap. They are very cautious creatures. They live in single-sex or mixed family groups of up to ten individuals, but old males live alone. They inhabit thickets within dense and dry savanna woodlands. The principal threats to
5247-419: The exception of the musk deer ), have one of four types of cranial appendages: true horns, antlers , ossicones , or pronghorns . True horns have a bone core that is covered in a permanent sheath of keratin, and are found only in the bovids . Antlers are bony structures that are shed and replaced each year; they are found in deer (members of the family Cervidae ). They grow from a permanent outgrowth of
5346-471: The feeding habits of the animal. Females reach sexual maturity at 11 to 12 months of age and males at 18 months (though they are socially immature until five years old), though they begin to show active spermatogenesis at 14 months. Before ovulation, the Graafian follicles reach a length of at least 6.7 cm (2.6 in). A female's estrous cycle is about 19 days long. Males will attempt to mate with
5445-459: The female for two days of the cycle, but she allows it for only six hours per cycle. When the male enters a females' herd during mating, he makes a display by raising his white dorsal crest, lowering his horns and moving stiffly. As in many other animals, the males fight over dominance during mating. The kidney fat indices (KFIs) of impalas and nyalas have been studied to understand the influence of social class and reproduction on them. To determine
5544-633: The form of a hoof ). The other three toes are either present, absent, vestigial , or pointing posteriorly. By contrast, most perissodactyls bear weight on an odd number of the five toes. Another difference between the two orders is that many artiodactyls (except for Suina ) digest plant cellulose in one or more stomach chambers rather than in their intestine (as perissodactyls do). Molecular biology, along with new fossil discoveries, has found that cetaceans ( whales , dolphins , and porpoises ) fall within this taxonomic branch, being most closely related to hippopotamuses . Some modern taxonomists thus apply
5643-1021: The former; the two groups together form a monophyletic taxon, for which the name Cetartiodactyla is sometimes used. Modern nomenclature divides Artiodactyla (or Cetartiodactyla) in four subordinate taxa: camelids (Tylopoda), pigs and peccaries (Suina), ruminants (Ruminantia), and hippos plus cetaceans (Whippomorpha). The presumed lineages within Artiodactyla can be represented in the following cladogram : Tylopoda (camels) [REDACTED] Suina (pigs) [REDACTED] Tragulidae (mouse deer) [REDACTED] Pecora (horn bearers) [REDACTED] Hippopotamidae (hippopotamuses) [REDACTED] Cetacea (whales) [REDACTED] The four summarized Artiodactyla taxa are divided into ten extant families: Although deer, musk deer, and pronghorns have traditionally been summarized as cervids (Cervioidea), molecular studies provide different—and inconsistent—results, so
5742-674: The frontal bone called the pedicle and can be branched, as in the white-tailed deer ( Odocoileus virginianus ), or palmate , as in the moose ( Alces alces ). Ossicones are permanent bone structures that fuse to the frontal or parietal bones during an animal's life and are found only in the Giraffidae . Pronghorns , while similar to horns in that they have keratinous sheaths covering permanent bone cores, are deciduous. All these cranial appendages can serve for posturing, battling for mating privilege, and for defense. In almost all cases, they are sexually dimorphic, and are often found only on
5841-401: The ground and for defense. In ruminants, the males' upper canines are enlarged and used as a weapon in certain species (mouse deer, musk deer, water deer ); species with frontal weapons are usually missing the upper canines. The lower canines of ruminants resemble the incisors, so that these animals have eight uniform teeth in the frontal part of the lower jaw . The molars of porcine have only
5940-841: The head held high and one leg raised. Sitatunga may occasionally emit a series of coughs or barks, usually at night, which may cause other animals to join in, and these sounds can be heard across the swamp. This barking may be used by females to warn off other females. Males often utter a low bellow on coming across a female or a herd of females in the mating season. A low-pitched squeak may be uttered while feeding. Mothers communicate with their calves by bleats. Sitatunga can feed or rest close to southern lechwe herds, but do not interact with them. They often attract yellow-billed oxpeckers , African jacanas and great egrets . Sitatunga are good swimmers, but limit themselves to water with profuse vegetation in order to escape crocodiles . In some cases, for instance when troubled by flies or pursued by predators,
6039-412: The head, coupled with the backward bend of the horns (in males) provides for easy navigation through dense vegetation. The pasterns are flexible, and the hooves, banana-like in shape, can reach a length of up to 16 cm (6.3 in) in the hindlegs and 18 cm (7.1 in) in the forelegs. The pointed toes allow it to walk slowly and almost noiselessly through the water. Moreover, the colour of
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#17327753038296138-556: The hot hours of the day. The nyala is very shy and cautious in nature, and often remains hidden rather than coming out in the open. Most sightings of the nyala in the wild are at water holes . But in protected areas they become less shy and often come out in view of tourists. Nyala groups are according to sex or mixed. Herds usually browse and drink water together. Each group consists of two to ten individuals. A study in Zinave National Park at Mozambique showed that 67% of
6237-442: The impala consumed more of them. The diet contained more proteins than fiber. Another study was done to find whether the sexual dimorphism in the nyala influenced its foraging habits. Vegetation surveys were conducted with the end of each feeding bout. It was found that females spent equal periods of time foraging in all the three habitats, but males preferred sand forest more. More differences were noted, as males ate woody species at
6336-407: The last third of gestation. Gestation is of seven months. A single calf is born, weighing 5 kg (11 lb). Birth takes place generally away from the sight of predators, in places such as a thicket. The calf remains hidden for up to 18 days, and the mother nurses it at regular intervals. The calf remains with its mother until the birth of the next calf, during which males in rut drive it away from
6435-601: The late Eocene and developed a great diversity of species in North America. Only in the late Miocene or early Pliocene did they migrate from North America into Eurasia. The North American varieties became extinct around 10,000 years ago. Suina (including pigs ) have been around since the Eocene. In the late Eocene or the Oligocene , two families stayed in Eurasia and Africa; the peccaries , which became extinct in
6534-407: The limbs are predominantly localized, which ensures that artiodactyls often have very slender legs. A clavicle is never present, and the scapula is very agile and swings back and forth for added mobility when running. The special construction of the legs causes the legs to be unable to rotate, which allows for greater stability when running at high speeds. In addition, many smaller artiodactyls have
6633-401: The male will begin attempts at mounting. At the time of mounting the female lowers her head, while the male first bends and then straightens his forelegs and rests his head and neck on her back. The two remain together for one or two days, during which time the male ensures that no other male can approach the female. Gestation lasts for nearly eight months, after which generally a single calf
6732-634: The males are consistently larger and heavier than the females. In deer, only the males boast antlers, and the horns of bovines are usually small or not present in females. Male Indian antelopes have a much darker coat than females. Almost all even-toed ungulates have fur, with the exception being the nearly hairless hippopotamus. Fur varies in length and coloration depending on the habitat. Species in cooler regions can shed their coat. Camouflaged coats come in colors of yellow, gray, brown, or black tones. Even-toed ungulates bear their name because they have an even number of toes (two or four)—in some peccaries,
6831-463: The males. One exception is the species Rangifer tarandus , known as reindeer in Europe or caribou in North America, where both sexes can grow antlers yearly, though the females' antlers are typically smaller and not always present. There are two trends in terms of teeth within Artiodactyla. The Suina and hippopotamuses have a relatively large number of teeth (with some pigs having 44); their dentition
6930-480: The most dominant nematodes in the antelope. Another study of 97 blood samples of South African nyalas revealed the presence of tick -borne hemoparasites (blood parasites). The methods used were polymerase chain reaction (PCR) and reverse line blot (RLB) hybridization. The dominant parasites were Theileria species, T. buffeli , T. bicornis , Ehrlichia species, Anaplasma marginale and A. bovis . Ten tick species, two louse species and
7029-542: The mother. The nyala inhabits dense lowland woodlands and thickets, mainly in southern Malawi, Mozambique, Zimbabwe, and eastern South Africa. It chooses places with good quality grasslands as well as provision of fresh water. It also inhabits lush green river country. The nyala's natural range stretches across southeast Africa from the Lower Shire Valley in Malawi through Mozambique and Zimbabwe to eastern South Africa and Eswatini. The geographic distribution of
7128-421: The mouse deer, often reaches a body length of only 45 centimeters (18 in) and a weight of 1.5 kilograms (3.3 lb). The largest member, the hippopotamus, can grow up to 5 meters (16 ft) in length and weigh 4.5 metric tons (5 short tons), and the giraffe can grow to be 5.5 meters (18 ft) tall and 4.7 meters (15 ft) in body length. All even-toed ungulates display some form of sexual dimorphism :
7227-948: The name Cetartiodactyla ( / s ɪ ˌ t ɑːr t i oʊ ˈ d æ k t ɪ l ə / ) to this group, while others opt to include cetaceans within the existing name of Artiodactyla. Some researchers use " even-toed ungulates " to exclude cetaceans and only include terrestrial artiodactyls, making the term paraphyletic in nature. The roughly 270 land-based even-toed ungulate species include pigs , peccaries , hippopotamuses , antelopes , deer , giraffes , camels , llamas , alpacas , sheep , goats and cattle . Many are herbivores, but suids are omnivorous, whereas cetaceans are entirely carnivorous. Artiodactyls are also known by many extinct groups such as anoplotheres , cainotheriids , merycoidodonts , entelodonts , anthracotheres , basilosaurids , and palaeomerycids . Many artiodactyls are of great dietary, economic, and cultural importance to humans. The oldest fossils of even-toed ungulates date back to
7326-439: The nyala is about 19 years. The coat is rusty or rufous brown in females and juveniles. It grows a dark brown or slate grey in adult males, often with a bluish tinge. Females and young males have ten or more white vertical stripes on their sides. Other markings are visible on the face, throat, flanks and thighs. Stripes are very reduced or absent in older males. Both males and females have a white chevron between their eyes, and
7425-621: The nyala may be based on the genetic variation. According to a study of nyala in South Africa, Mozambique, Malawi and Zimbabwe, there was a marked difference in the gene frequencies at three microsatellite loci . Mitochondrial DNA analysis revealed the presence of a unique haplotype in individuals from each location. Thus, the geographic variation in the nyala may be due to a distribution pattern based on habitat specificity. Today nyala are found in South African protected areas in
7524-462: The nyala, it was found that Vitamin E levels varied during stress. A study of the helminths from 77 nyalas from four game reserves in Natal revealed the presence of ten nematode species and four nematode genera, a trematode species and paramphistomes (members of superfamily Paramphistomoidea ), and two cestode genera. The research discovered new parasites that the nyala was host of - namely
7623-416: The observations were of groups of one to three nyalas, and the rest of the herds consisted of up to 30 nyalas. Herds often broke up and re-formed. Generally adult males remain alone. Females often remain near their mothers when they have their offspring, so the relationships in female herds may be closer than those of males. Alert and wary in nature, the nyala use a sharp, high, dog-like bark to warn others in
7722-442: The plate (top and sides), the sole (bottom), and the bale (rear). In general, the claws of the forelegs are wider and blunter than those of the hind legs, and they are farther apart. Aside from camels, all even-toed ungulates put just the tip of the foremost phalanx on the ground. In even-toed ungulates, the bones of the stylopodium (upper arm or thigh bone) and zygopodiums (tibia and fibula) are usually elongated. The muscles of
7821-888: The population of the nyala are poaching, habitat loss, agriculture and cattle grazing. Rinderpest outbreaks have also contributed in population loss. This species is currently of Least Concern , and the population is considered stable by both the IUCN and CITES . As of 1999, the total population of the nyala was around 32,000 individuals. More recent estimates show that South Africa has at least 30,000 nyalas, with 25,000 in KwaZulu-Natal. There are now more than 1,000 on protected areas and ranches in Eswatini. In Mozambique there are not more than 3,000, in Zimbabwe over 1,000, and numbers in Malawi have fallen from 3,000 to about 1,500. Namibia has
7920-429: The premature death of cells in a living tissue) and mineralization were found in the skeletal muscle after a histological analysis. In the juveniles there was acute necrosis of the cardiac muscle . In adults, there was interstitial fibrosis of the cardiac muscle, along with arteriosclerosis . In a report published in 1994 entitled "Epidemiological observations on spongiform encephalopathies in captive wild animals in
8019-538: The proto-lesser kudu, but the two have remained separate long after this crossing. The nyala is a spiral-horned and middle-sized antelope, between a bushbuck and a kudu . It is considered the most sexually dimorphic antelope. The nyala is typically between 135–195 cm (53–77 in) in head-and-body length. The male stands up to 110 cm (43 in), the female is up to 90 cm (3.0 ft) tall. Males weigh 98–125 kg (216–276 lb), while females weigh 55–68 kg (121–150 lb). Life expectancy of
8118-413: The question of phylogenetic systematics of infraorder Pecora (the horned ruminants) for the time being, cannot be answered. Artiodactyls are generally quadrupeds . Two major body types are known: suinids and hippopotamuses are characterized by a stocky body, short legs, and a large head; camels and ruminants, though, have a more slender build and lanky legs. Size varies considerably; the smallest member,
8217-624: The rainy season they feed upon the fresh grass. They need a regular intake of water, and thus choose places with a water source nearby. However, they are adapted to live in areas with only a seasonal availability of water. A study in Zululand showed that the nyala fed mainly in the early morning and the late afternoon. They feed at night during the rainy season. A study in Mkhuze Game Reserve and Ndumu Game Reserve in Natal focused on
8316-410: The seasonal movement and diet of the species. These floods force the animals out of the reed beds onto the flooded grasslands when the water levels are high. At low water levels the cattle take over the flooded plains and send the sitatunga back to their original place. Females are sexually mature by one year of age, while males take one-and-a-half-year before they mature. Breeding occurs throughout
8415-472: The sequence with that of other living beings—the more similar they are, the more closely they are related. Comparison of even-toed ungulate and cetaceans genetic material has shown that the closest living relatives of whales and hippopotamuses is the paraphyletic group Artiodactyla. Dan Graur and Desmond Higgins were among the first to come to this conclusion, and included a paper published in 1994. However, they did not recognize hippopotamuses and classified
8514-661: The sitatunga at a lake named "Little Windermere" (now Lake Lwelo, located in Kagera , Tanzania ). In his book Journal of the Discovery of the Source of the Nile , Speke called the animal "nzoé" ( Kiswahili name for the animal) or "water-boc" (due to its resemblance to the waterbuck ). The word "sitatunga" itself comes from an ancient Bantu language. The scientific name has often been misstated as T. spekei , and either Speke or Sclater
8613-1184: The sitatunga might fully submerge themselves in the water except for the nose and the eyes, which they keep slightly above the water surface. Due to its close association with water, the sitatunga are often described as " aquatic antelopes", like the waterbuck . They often dry themselves under the sun after feeding in water. Predators of the sitatunga include lions , wild dogs , crocodiles and leopards . Sitatunga are selective and mixed feeders. They feed mainly on new foliage, fresh grasses, sedges and browse. Preferred plants include: bullrushes ( Typha ), sedges ( Cyperus ), aquatic grasses ( Vossia , Echinochloa , Pennisetum , Leersia , Acroceras and Panicum . Species in Umbelliferae and Acanthaceae are preferred in Saiwa Swamp National Park (Kenya), and Fabaceae species are preferred in Bangweulu and Busanga (in Kafue National Park ). They feed mostly in
8712-668: The size of a wolf) and Ichthyolestes (an early whale the size of a fox) were found in Pakistan. They were both archaeocetes ("ancient whales") from about 48 million years ago (in the Eocene). These findings showed that archaeocetes were more terrestrial than previously thought, and that the special construction of the talus (ankle bone) with a double-rolled joint surface, previously thought to be unique to even-toed ungulates, were also in early cetaceans. The mesonychians , another type of ungulate, did not show this special construction of
8811-724: The smallest population, at about 250. Today over 80% of the total population is protected in national parks and sanctuaries, mostly in South African protected areas. In South Africa there is a high demand for adult males as game trophies. Artiodactyl Cetartiodactyla Montgelard et al. 1997 Artiodactyls are placental mammals belonging to the order Artiodactyla ( / ˌ ɑːr t i oʊ ˈ d æ k t ɪ l ə / AR -tee-oh- DAK -tih-lə , from Ancient Greek ἄρτιος , ártios 'even' and δάκτυλος , dáktylos 'finger, toe'). Typically, they are ungulates which bear weight equally on two (an even number) of their five toes (the third and fourth, often in
8910-988: The specialised gait of the sitatunga, and thus often loses its balance and falls in water. Males, and even some females, have been observed to leave their herds even before reaching sexual maturity due to intrasexual competition. Lifespan recorded in captivity averages 22 to 23 years. The sitatunga is an amphibious antelope (meaning it can live on both land and water) confined to swampy and marshy habitats. They occur in tall and dense vegetation of perennial as well as seasonal swamps, marshy clearings in forests, riparian thickets and mangrove swamps. Sitatunga move along clearly marked tracks in their swampy habitat, often leading to reed beds. These tracks, up to 7 m (23 ft) wide, can lead to feeding grounds and nearby riverine forests. The sitatunga hold small home ranges near water bodies In savannas, they are typically found in stands of papyrus and reeds ( Phragmites species and Echinochloa pyramidalis ). They share their habitat with
9009-493: The species are illegal poaching and habitat loss resulting from human settlement and livestock grazing. However, the large-horned, impressive males are highly prized as game animals by sport hunters. Giant eland Common eland Greater kudu Mountain nyala Bongo Sitatunga Cape bushbuck Harnessed bushbuck Lowland nyala Lesser kudu The nyala was first described by George French Angas , an English naturalist, in 1849. The scientific name of nyala
9108-409: The survival of the sitatunga. Other threats include the increasing loss of wetlands, that has isolated populations; and long-term changes in the water level, that affects the nearby vegetation and thus bears upon their diet. Vast areas of Bangweulu and Busanga are burnt every year, placing animals like the sitatunga at grave risk given the inflammability of swamps. The sitatunga has been classified under
9207-521: The talus, and thus was concluded to not have the same ancestors as cetaceans. The oldest cetaceans date back to the early Eocene (53 million years ago), whereas the oldest known hippopotamus dates back only to the Miocene (15 million years ago). The hippopotamids are descended from the anthracotheres, a family of semiaquatic and terrestrial artiodactyls that appeared in the late Eocene, and are thought to have resembled small- or narrow-headed hippos. Research
9306-479: The traditional order Artiodactyla and infraorder Cetacea are sometimes subsumed into the more inclusive Cetartiodactyla taxon. An alternative approach is to include both land-dwelling even-toed ungulates and ocean-dwelling cetaceans in a revised Artiodactyla taxon. In the 1990s, biological systematics used not only morphology and fossils to classify organisms, but also molecular biology . Molecular biology involves sequencing an organism's DNA and RNA and comparing
9405-522: The wetland fringes. Diet preferences may vary seasonally in swamps where water levels change notably. Like the gerenuk , the sitatunga may stand on its hindlegs to reach higher branches of trees, or even use its horns to pull down the branches. A study recorded forty major species eaten by the animal, the majority of which were herbs. Sweet potato was the most preferred crop. The study predicted an increase in preference for crops due to seasonal food variations. Another study showed that annual floods affect
9504-440: The year. When females gather, the males compete among each other for the right to mate, showing polygyny in males. The rutting male approaches the female in a lower bending posture, sniffing her vulva . The female may move slowly or react nervously. Even if the female flees, the male continues pursuing her steadily, without showing any sign of hurry. A receptive female will raise her head with her mouth wide open, following which
9603-426: Was hotly debated because ocean-dwelling cetaceans evolved from land-dwelling even-toed ungulates. Some semiaquatic even-toed ungulates ( hippopotamuses ) are more closely related to ocean-dwelling cetaceans than to other even-toed ungulates. Phylogenetic classification only recognizes monophyletic taxa; that is, groups that descend from a common ancestor and include all of its descendants. To address this problem,
9702-542: Was proposed in 1912 by American zoologist Edmund Heller , who also proposed Ammelaphus for the lesser kudu, but it was not widely recognized. It was re-erected as a valid genus in 2011 under the classification of Peter Grubb and Colin Groves , but has not been embraced by taxonomic authorities such as the Mammal Diversity Database. Among its closest extant relatives are the forest-inhabiting bongo ,
9801-621: Was widely accepted by the end of the 20th century was: Suidae [REDACTED] Hippopotamidae [REDACTED] Tylopoda [REDACTED] Tragulidae [REDACTED] Pecora [REDACTED] Modern cetaceans are highly adapted sea creatures which, morphologically, have little in common with land mammals; they are similar to other marine mammals , such as seals and sea cows , due to convergent evolution . However, they evolved from originally terrestrial mammals. The most likely ancestors were long thought to be mesonychians—large, carnivorous animals from
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