Nocturnality is a behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is " nocturnal ", versus diurnal meaning the opposite.
99-467: Nocturnal creatures generally have highly developed senses of hearing , smell , and specially adapted eyesight . Some animals, such as cats and ferrets , have eyes that can adapt to both low-level and bright day levels of illumination (see metaturnal ). Others, such as bushbabies and (some) bats , can function only at night. Many nocturnal creatures including tarsiers and some owls have large eyes in comparison with their body size to compensate for
198-740: A Blue Table and the various paintings of Mary Fedden and Sidney Nolan . Victor Vasarely depicted zebras as black and white lines and connected in a jigsaw puzzle fashion. Carel Weight 's Escape of the Zebra from the Zoo during an Air Raid was based on a real life incident of a zebra escaping during the bombing of London Zoo and consists of four comic book-like panels. Zebras have lent themselves to products and advertisements, notably for 'Zebra Grate Polish' cleaning supplies by British manufacturer Reckitt and Sons and Japanese pen manufacturer Zebra Co., Ltd. Zebras have been kept in captivity since at least
297-582: A clinical setting, this management is offered by otologists and audiologists . Hearing loss is associated with Alzheimer's disease and dementia with a greater degree of hearing loss tied to a higher risk. There is also an association between type 2 diabetes and hearing loss . Hearing threshold and the ability to localize sound sources are reduced underwater in humans, but not in aquatic animals, including whales, seals, and fish which have ears adapted to process water-borne sound. Not all sounds are normally audible to all animals. Each species has
396-538: A common ancestor who evolved to function as a nocturnal species, decreasing their eyesight in favor of a better sense of smell. The anomaly to this theory were anthropoids , who appeared to have the most divergence from nocturnality of all organisms examined. While most mammals did not exhibit the morphological characteristics expected of a nocturnal creature, reptiles and birds fit in perfectly. A larger cornea and pupil correlated well with whether these two classes of organisms were nocturnal or not. Being active at night
495-405: A curled lip and bared teeth ( flehmen response ) and the female will solicit mating by backing in. Gestation is typically around a year. A few days to a month later, mares can return to oestrus. In harem-holding species, oestrus in a female becomes less noticeable to outside males as she gets older, hence competition for older females is virtually nonexistent. Usually, a single foal is born, which
594-483: A decrease in mate calls and continued to move around instead of waiting for a potential mate to arrive. This hurts the overall fitness of the species, which is concerning considering the overall decrease in amphibian populations. Predation Some nocturnal predator-prey relationships are interrupted by artificial lighting. Bats that are fast-moving are often at an advantage with insects being drawn to light; they are fast enough to escape any predators also attracted to
693-492: A distinct species. Later genetic studies have placed it as the same species as the plains zebra, either a subspecies or just the southernmost population. Molecular evidence supports zebras as a monophyletic lineage . Equus originated in North America and direct paleogenomic sequencing of a 700,000-year-old middle Pleistocene horse metapodial bone from Canada implies a date of 4.07 million years ago (mya) for
792-477: A harem nibble and rake along the neck, shoulder, and back with their teeth and lips. Grooming usually occurs between mothers and foals and between stallions and mares. Grooming establishes social rank and eases aggressive behaviour, although Grévy's zebras generally do not perform social grooming. Among plains and mountain zebras, the adult females mate only with their harem stallion, while in Grévy's zebras, mating
891-503: A harem stallion is healthy, he is not usually challenged. Only unhealthy stallions have their harems taken over, and even then, the new stallion slowly takes over, peacefully displacing the old one. Agonistic behaviour between male Grévy's zebras occurs at the border of their territories. Zebras produce a number of vocalisations and noises. The plains zebra has a distinctive, barking contact call heard as "a- ha , a- ha , a- ha " or "kwa-ha, kaw-ha, ha, ha". The mountain zebra may produce
990-603: A long initial vowel, but over the course of the 20th century the pronunciation with the short initial vowel became the norm in British English . The pronunciation with a long initial vowel remains standard in American English . Zebras are classified in the genus Equus (known as equines) along with horses and asses . These three groups are the only living members of the family Equidae . The plains zebra and mountain zebra were traditionally placed in
1089-417: A major effect on nocturnal animals, as well as diurnal species. The causes of these can be traced to distinct, sometimes overlapping areas: light pollution and spatial disturbance. Light pollution is a major issue for nocturnal species, and the impact continues to increase as electricity reaches parts of the world that previously had no access. Species in the tropics are generally more affected by this due to
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#17327837920521188-497: A measure as employing an anechoic chamber , which absorbs nearly all sound. Another means is the use of devices such as earplugs , which are inserted into the ear canal to block noise, or earmuffs , objects designed to cover a person's ears entirely. The loss of hearing, when it is caused by neural loss, cannot presently be cured. Instead, its effects can be mitigated by the use of audioprosthetic devices, i.e. hearing assistive devices such as hearing aids and cochlear implants . In
1287-492: A number of threats to the different endangered species. Adults are likely to stay away from artificially lit beaches that they might prefer to lay eggs on, as there is less cover against predators. Additionally, baby sea turtles that hatch from eggs on artificially lit beaches often get lost, heading towards the light sources as opposed to the ocean. Rhythmic behaviors are affected by light pollution both seasonally and daily patterns. Migrating birds or mammals might have issues with
1386-438: A range of normal hearing for both amplitude and frequency . Many animals use sound to communicate with each other, and hearing in these species is particularly important for survival and reproduction. In species that use sound as a primary means of communication, hearing is typically most acute for the range of pitches produced in calls and speech. Frequencies capable of being heard by humans are called audio or sonic. The range
1485-491: A result of human expansion has given both advantages and disadvantages to different nocturnal animals. As a result of peak human activity in the daytime, more species are likely to be active at night in order to avoid the new disturbance in their habitat. Carnivorous predators however are less timid of the disturbance, feeding on human waste and keeping a relatively similar spatial habitat as they did before. In comparison, herbivorous prey tend to stay in areas where human disturbance
1584-595: A similar sound while the call of Grévy's zebra has been described as "something like a hippo 's grunt combined with a donkey's wheeze". Loud snorting and rough "gasping" in zebras signals alarm. Squealing is usually made when in pain, but can also be heard in friendly interactions. Zebras also communicate with visual displays, and the flexibility of their lips allows them to make complex facial expressions. Visual displays also consist of head, ear, and tail postures. A zebra may signal an intention to kick by dropping back its ears and whipping its tail. Flattened ears, bared teeth and
1683-447: A spade-shaped toe covered in a hard hoof . Their dentition is adapted for grazing ; they have large incisors that clip grass blades and rough molars and premolars well suited for grinding. Males have spade-shaped canines, which can be used as weapons in fighting. The eyes of zebras are at the sides and far up the head, which allows them to look over the tall grass while feeding. Their moderately long, erect ears are movable and can locate
1782-435: A territory offers a female protection from harassment by outside males, as well as access to resources. In all species, excess males gather in bachelor groups . These are typically young males that are not yet ready to establish a harem or territory. With the plains zebra, the oldest males are the most dominant and group membership is stable. Bachelor groups tend to be at the boundaries of herds and during group movements,
1881-701: A variety of habitats such as savannahs , grasslands , woodlands, shrublands , and mountainous areas. Zebras are primarily grazers and can subsist on lower-quality vegetation. They are preyed on mainly by lions , and typically flee when threatened but also bite and kick. Zebra species differ in social behaviour , with plains and mountain zebra living in stable harems consisting of an adult male or stallion , several adult females or mares , and their young or foals ; while Grévy's zebra live alone or in loosely associated herds. In harem-holding species, adult females mate only with their harem stallion, while male Grévy's zebras establish territories which attract females and
1980-502: A waving head may be used as threatening gestures by stallions. Individuals may greet each other by rubbing and sniffing and then mutually rub their cheeks, and move along their bodies towards each other's genitals to sniff. They then may caress their shoulders against each other and lay their heads on one another. This greeting usually occurs between harem or territorial males or among bachelor males playing. Plains and mountain zebras strengthen their social bonds with grooming . Members of
2079-405: A week without water but will drink it every day when given the chance, and their bodies maintain water better than cattle. Mountain zebras can be found at elevations of up to 2,000 m (6,600 ft). Zebras sleep for seven hours a day, standing up during the day and lying down during the night. They regularly use various objects as rubbing posts and will roll on the ground . A zebra's diet
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#17327837920522178-603: A zebra from Ethiopia in 1620 and Ustad Mansur made a painting of it. In the 1670s, Ethiopian Emperor Yohannes I exported two zebras to the Dutch governor of Jakarta . These animals would eventually be given by the Dutch to the Tokugawa Shogunate of Japan. When Queen Charlotte received a zebra as a wedding gift in 1762, the animal became a source of fascination for the people of Britain. Many flocked to see it at its paddock at Buckingham Palace . It soon became
2277-413: Is filtered differently on its way into the ear depending on the location of its origin. This gives these animals the ability to localize sound vertically . The eardrum is an airtight membrane, and when sound waves arrive there, they cause it to vibrate following the waveform of the sound. Cerumen (ear wax) is produced by ceruminous and sebaceous glands in the skin of the human ear canal, protecting
2376-696: Is pollination - nocturnal pollinators such as moths, beetles, thrips, and bats have a lower risk of being seen by predators, and the plants evolved temporal scent production and ambient heat to attract nocturnal pollination. Like with predators hunting the same prey, some plants such as apples can be pollinated both during the day and at night. Nocturnality is a form of crypsis , an adaptation to avoid or enhance predation . Although lions are cathemeral , and may be active at any time of day or night, they prefer to hunt at night because many of their prey species ( zebra , antelope , impala, wildebeest , etc.) have poor night vision . Many species of small rodents, such as
2475-449: Is a form of niche differentiation , where a species' niche is partitioned not by the amount of resources but by the amount of time (i.e. temporal division of the ecological niche ). Hawks and owls can hunt the same field or meadow for the same rodents without conflict because hawks are diurnal and owls are nocturnal. This means they are not in competition for each other's prey. Another niche that being nocturnal lessens competition within
2574-409: Is avoiding the heat of the day. This is especially true in arid biomes like deserts , where nocturnal behavior prevents creatures from losing precious water during the hot, dry daytime. This is an adaptation that enhances osmoregulation . One of the reasons that ( cathemeral ) lions prefer to hunt at night is to conserve water. Hamiltons Frog , found on Stephens and Maud islands, stays hidden for
2673-610: Is capable of running within an hour of birth. A newborn zebra will follow anything that moves, so new mothers prevent other mares from approaching their foals as they become more familiar with the mother's striping pattern, smell and voice. At a few weeks old, foals begin to graze, but may continue to nurse for eight to thirteen months. Living in an arid environment, Grévy's zebras have longer nursing intervals and young only begin to drink water three months after birth. In plains and mountain zebras, foals are cared for mostly by their mothers, but if threatened by pack-hunting hyenas and dogs,
2772-434: Is low, limiting both resources and their spatial habitat. This leads to an imbalance in favor of predators, who increase in population and come out more often at night. In zoos , nocturnal animals are usually kept in special night-illumination enclosures to invert their normal sleep-wake cycle and to keep them active during the hours when visitors will be there to see them. Hedgehogs and sugar gliders are just two of
2871-416: Is more promiscuous and the males have larger testes for sperm competition . Female zebras have five to ten day long oestrous cycles; physical signs include a swollen, everted (inside out) labia and copious flows of urine and mucus. Upon reaching peak oestrous, mares spread-out their legs, lift their tails and open their mouths when in the presence of a male. Males assess the female's reproductive state with
2970-402: Is mostly grasses and sedges , but they will opportunistically consume bark , leaves, buds, fruits, and roots. Compared to ruminants , zebras have a simpler and less efficient digestive system. Nevertheless, they can subsist on lower-quality vegetation. Zebras may spend 60–80% of their time feeding, depending on the availability of vegetation. The plains zebra is a pioneer grazer, mowing down
3069-462: Is not directly coupled with frequency range. Georg Von Békésy in 1929 identifying sound source directions suggested humans can resolve timing differences of 10μs or less. In 1976 Jan Nordmark's research indicated inter-aural resolution better than 2μs. Milind Kuncher's 2007 research resolved time misalignment to under 10μs. Even though they do not have ears, invertebrates have developed other structures and systems to decode vibrations traveling through
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3168-428: Is not needed anymore due to the evolution of compensatory sensory systems, such as a heightened sense of smell and more astute auditory systems. In a recent study, recently extinct elephant birds and modern day nocturnal kiwi bird skulls were examined to recreate their likely brain and skull formation. They indicated that olfactory bulbs were much larger in comparison to their optic lobes , indicating they both have
3267-425: Is performed primarily by the auditory system : mechanical waves , known as vibrations, are detected by the ear and transduced into nerve impulses that are perceived by the brain (primarily in the temporal lobe ). Like touch , audition requires sensitivity to the movement of molecules in the world outside the organism. Both hearing and touch are types of mechanosensation . There are three main components of
3366-401: Is possible that having evolved under pressure from the many large predators of Africa, including early humans, they became more aggressive, thus making domestication more difficult. However, zebras have been trained throughout history. In Rome, zebras are recorded to have pulled chariots during amphitheatre games starting in the reign of Caracalla (198 to 217 AD). In the late 19th century,
3465-442: Is the ability to perceive sounds through an organ, such as an ear , by detecting vibrations as periodic changes in the pressure of a surrounding medium. The academic field concerned with hearing is auditory science . Sound may be heard through solid , liquid , or gaseous matter. It is one of the traditional five senses . Partial or total inability to hear is called hearing loss . In humans and other vertebrates, hearing
3564-414: Is the main organ of mechanical to neural transduction . Inside the organ of Corti is the basilar membrane , a structure that vibrates when waves from the middle ear propagate through the cochlear fluid – endolymph . The basilar membrane is tonotopic , so that each frequency has a characteristic place of resonance along it. Characteristic frequencies are high at the basal entrance to the cochlea, and low at
3663-430: Is the use of devices designed to prevent noise-induced hearing loss (NIHL), a type of post-lingual hearing impairment . The various means used to prevent hearing loss generally focus on reducing the levels of noise to which people are exposed. One way this is done is through environmental modifications such as acoustic quieting , which may be achieved with as basic a measure as lining a room with curtains , or as complex
3762-521: Is thought to be responsible for the differences in the striping patterns of the different species. Various abnormalities of the patterns have been documented in plains zebras. In " melanistic " zebras, dark stripes are highly concentrated on the torso but the legs are whiter. "Spotted" individuals have broken up black stripes around the dorsal area. There have even been morphs with white spots on dark backgrounds. Striping abnormalities have been linked to inbreeding . Albino zebras have been recorded in
3861-494: Is typically considered to be between 20 Hz and 20,000 Hz. Frequencies higher than audio are referred to as ultrasonic , while frequencies below audio are referred to as infrasonic . Some bats use ultrasound for echolocation while in flight. Dogs are able to hear ultrasound, which is the principle of 'silent' dog whistles . Snakes sense infrasound through their jaws, and baleen whales , giraffes , dolphins and elephants use it for communication. Some fish have
3960-533: The African diaspora , the zebra represented the politics of race and identity, being both black and white. In cultures outside of its range, the zebra has been thought of as a more exotic alternative to the horse; the comic book character Sheena, Queen of the Jungle , is depicted riding a zebra and explorer Osa Johnson was photographed riding one. The film Racing Stripes features a captive zebra ostracised from
4059-809: The IUCN Red List of mammals lists Grévy's zebra as endangered , the mountain zebra as vulnerable and the plains zebra as near-threatened . Grévy's zebra populations are estimated at less than 2,000 mature individuals, but they are stable. Mountain zebras number near 35,000 individuals and their population appears to be increasing. Plains zebra are estimated to number 150,000–250,000 with a decreasing population trend. Human intervention has fragmented zebra ranges and populations. Zebras are threatened by hunting for their hide and meat, and habitat destruction . They also compete with livestock and have their travelling routes obstruct by fences. Civil wars in some countries have also caused declines in zebra populations. By
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4158-482: The Large Japanese Field Mouse , are active at night because most of the dozen or so birds of prey that hunt them are diurnal. There are many diurnal species that exhibit some nocturnal behaviors. For example, many seabirds and sea turtles only gather at breeding sites or colonies at night to reduce the risk of predation to themselves and/or their offspring. Nocturnal species take advantage of
4257-463: The Mesozoic , many ancestors of modern-day mammals evolved nocturnal characteristics in order to avoid contact with the numerous diurnal predators. A recent study attempts to answer the question as to why so many modern day mammals retain these nocturnal characteristics even though they are not active at night. The leading answer is that the high visual acuity that comes with diurnal characteristics
4356-586: The Roman Empire . In later times, captive zebras have been shipped around the world, often for diplomatic reasons. In 1261, Sultan Baibars of Egypt established an embassy with Alfonso X of Castile and sent a zebra and other exotic animals as gifts. In 1417, a zebra was gifted to the Chinese people by Somalia and displayed before the Yongle Emperor . The fourth Mughal emperor Jahangir received
4455-506: The medial geniculate nucleus , a part of the thalamus where sound information is relayed to the primary auditory cortex in the temporal lobe . Sound is believed to first become consciously experienced at the primary auditory cortex . Around the primary auditory cortex lies Wernickes area , a cortical area involved in interpreting sounds that is necessary to understand spoken words. Disturbances (such as stroke or trauma ) at any of these levels can cause hearing problems, especially if
4554-413: The metaconid and metastylid of the tooth by a V-shaped canal and rounded enamel wall . Zebras are easily recognised by their bold black-and-white striping patterns. The coat appears to be white with black stripes, as indicated by the belly and legs when unstriped, but the skin is black. Young or foals are born with brown and white coats, and the brown darkens with age. A dorsal line acts as
4653-480: The plains zebra ( E. quagga ), and the mountain zebra ( E. zebra ). Zebras share the genus Equus with horses and asses , the three groups being the only living members of the family Equidae . Zebra stripes come in different patterns, unique to each individual. Several theories have been proposed for the function of these patterns, with most evidence supporting them as a deterrent for biting flies. Zebras inhabit eastern and southern Africa and can be found in
4752-470: The subgenus Hippotigris (C. H. Smith, 1841) in contrast to the Grévy's zebra which was considered the sole species of subgenus Dolichohippus (Heller, 1912). Groves and Bell (2004) placed all three species in the subgenus Hippotigris . A 2013 phylogenetic study found that the plains zebra is more closely related to Grévy's zebras than mountain zebras. The extinct quagga was originally classified as
4851-958: The Eurasian Equus ovodovi and the subgenus Sussemionus lineage as closer to zebras than to asses. However, other studies disputed this placement, finding the Sussemionus lineage basal to the zebra+asses group, but suggested that the Sussemionus lineage may have received gene flow from zebras. The cladogram of Equus below is based on Vilstrup and colleagues (2013) and Jónsson and colleagues (2014): Mountain zebra ( E. zebra ) [REDACTED] Plains zebra ( E. quagga ) [REDACTED] Grévy's zebra ( E. grevyi ) [REDACTED] Kiang ( E. kiang ) [REDACTED] Onager ( E. hemionus ) [REDACTED] African wild ass ( E. africanus ) [REDACTED] Horse ( E. ferus caballus ) [REDACTED] Przewalski's horse ( E. ferus przewalski ) [REDACTED] In addition to
4950-406: The ability to hear more sensitively due to a well-developed, bony connection between the ear and their swim bladder. This "aid to the deaf" for fishes appears in some species such as carp and herring . Human perception of audio signal time separation has been measured to less than 10 microseconds (10μs). This does not mean that frequencies above 100 kHz are audible, but that time discrimination
5049-567: The air, or “sound”. Charles Henry Turner was the first scientist to formally show this phenomenon through rigorously controlled experiments in ants. Turner ruled out the detection of ground vibration and suggested that other insects likely have auditory systems as well. Many insects detect sound through the way air vibrations deflect hairs along their body. Some insects have even developed specialized hairs tuned to detecting particular frequencies, such as certain caterpillar species that have evolved hair with properties such that it resonates most with
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#17327837920525148-475: The animals are often used to represent the letter 'Z'. Zebra stripe patterns are popularly used for body paintings, dress, furniture and architecture. Zebras have been featured in African art and culture for millennia. They are depicted in rock art in Southern Africa dating from 28,000 to 20,000 years ago, though less often than antelope species like eland . How the zebra got its stripes has been
5247-487: The apex. Basilar membrane motion causes depolarization of the hair cells , specialized auditory receptors located within the organ of Corti. While the hair cells do not produce action potentials themselves, they release neurotransmitter at synapses with the fibers of the auditory nerve , which does produce action potentials. In this way, the patterns of oscillations on the basilar membrane are converted to spatiotemporal patterns of firings which transmit information about
5346-406: The artificial lighting. Insects are the most obvious example, who are attracted by the lighting and are usually killed by either the heat or electrical current. Some species of frogs are blinded by the quick changes in light, while nocturnal migratory birds may be disoriented, causing them to lose direction, tire out, or be captured by predators. Sea turtles are particularly affected by this, adding to
5445-778: The bachelors follow behind or along the sides. Mountain zebra bachelor groups may also include young females that have left their natal group early, as well as old, former harem males. A territorial Grévy's zebra stallion may allow non-territorial bachelors in their territory, however when a mare in oestrous is present the territorial stallion keeps other stallions at bay. Bachelors prepare for their future harem roles with play fights and greeting/challenge rituals, which make up most of their activities. Fights between males usually occur over mates and involve biting and kicking. In plains zebra, stallions fight each other over recently matured mares to bring into their group and her family stallion will fight off other males trying to abduct her. As long as
5544-409: The backbone for vertical stripes along the sides, from the head to the rump. On the snout they curve toward the nostrils, while the stripes above the front legs split into two branches. On the rump, they develop into species-specific patterns. The stripes on the legs, ears and tail are separate and horizontal. Striping patterns are unique to an individual and heritable. During embryonic development ,
5643-780: The big cats. In one study, the maximum speed of a zebra was found to be 50 km/h (31 mph) while a lion was measured at 74 km/h (46 mph). Zebras do not escape lions by speed alone but by sideways turning, especially when the cat is close behind. With smaller predators like hyenas and dogs, zebras may act more aggressively, especially in defense of their young. Zebra species have two basic social structures. Plains and mountain zebras live in stable, closed family groups or harems consisting of one stallion , several mares , and their offspring. These groups have their own home ranges , which overlap, and they tend to be nomadic. Stallions form and expand their harems by recruiting young mares from their natal (birth) harems. The stability of
5742-427: The change in their relatively constant light patterns, but temperate species relying on day-night triggers for behavioral patterns are also affected as well. Many diurnal species see the benefit of a "longer day", allowing for a longer hunting period which is detrimental to their nocturnal prey trying to avoid them. Light pollution can disorient species that are used to darkness, as their adaptive eyes are not as used to
5841-399: The daytime. Crepuscular species, such as rabbits , skunks , tigers and hyenas , are often erroneously referred to as nocturnal. Cathemeral species, such as fossas and lions , are active both in the day and at night. While it is difficult to say which came first, nocturnality or diurnality, a hypothesis in evolutionary biology , the nocturnal bottleneck theory, postulates that in
5940-723: The disturbance is bilateral . In some instances it can also lead to auditory hallucinations or more complex difficulties in perceiving sound. Hearing can be measured by behavioral tests using an audiometer . Electrophysiological tests of hearing can provide accurate measurements of hearing thresholds even in unconscious subjects. Such tests include auditory brainstem evoked potentials (ABR), otoacoustic emissions (OAE) and electrocochleography (ECochG). Technical advances in these tests have allowed hearing screening for infants to become widespread. Hearing can be measured by mobile applications which includes audiological hearing test function or hearing aid application . These applications allow
6039-414: The ear canal and tympanic membrane from physical damage and microbial invasion. The middle ear consists of a small air-filled chamber that is located medial to the eardrum. Within this chamber are the three smallest bones in the body, known collectively as the ossicles which include the malleus, incus, and stapes (also known as the hammer, anvil, and stirrup, respectively). They aid in the transmission of
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#17327837920526138-523: The early 20th century, zebra skins were being used to make rugs and chairs. In the 21st century, zebras may be taken by trophy hunters as zebra skin rugs sell for $ 1,000 to $ 2,000. Trophy hunting was rare among African peoples though the San were known to hunt zebra for meat. The quagga ( E. quagga quagga ) population was hunted by early Dutch settlers and later by Afrikaners to provide meat or for their skins. The skins were traded or used locally. The quagga
6237-586: The entire group works together to protect all the young. The group forms a protective front with the foals in the centre, and the stallion will rush at predators that come too close. In Grévy's zebras, young stay in " kindergartens " when their mothers leave for water. These groups are tended to by the territorial male. A stallion may look after a foal in his territory to ensure that the mother stays, though it may not be his. By contrast, plains zebra stallions are generally intolerant of foals that are not theirs and may practice infanticide and feticide via violence to
6336-468: The females that enter them. Grazing and drinking areas tend to be separated in these environments and the most dominant males establish territories near watering holes, which attract females with dependent foals and those who simply want a drink, while less dominant males control territories away from water with more vegetation, and only attract mares without foals. Mares may travel through several territories but remain in one when they have young. Staying in
6435-502: The forests of Mount Kenya , with the dark stripes being blonde. The quagga had brown and white stripes on the head and neck, brown upper parts and a white belly, tail and legs. The function of stripes in zebras has been discussed among biologists since at least the 19th century. Popular hypotheses include the following: Zebras may travel or migrate to wetter areas during the dry season. Plains zebras have been recorded travelling 500 km (310 mi) between Namibia and Botswana,
6534-412: The group remains even when the family stallion is displaced. Plains zebras groups gather into large herds and may create temporarily stable subgroups within a herd, allowing individuals to interact with those outside their group. Females in harems can spend more time feeding, and gain protection both for them and their young. The females have a linear dominance hierarchy with the high-ranking females being
6633-481: The horses and ends up being ridden by a rebellious girl. Zebras have been featured as characters in animated films like Khumba , The Lion King and the Madagascar films and television series such as Zou . Zebras have been popular subjects for abstract , modernist and surrealist artists. Such art includes Christopher Wood 's Zebra and Parachute , Lucian Freud 's The Painter's Room and Quince on
6732-401: The human auditory system : the outer ear, the middle ear, and the inner ear. The outer ear includes the pinna , the visible part of the ear, as well as the ear canal , which terminates at the eardrum , also called the tympanic membrane. The pinna serves to focus sound waves through the ear canal toward the eardrum. Because of the asymmetrical character of the outer ear of most mammals, sound
6831-415: The inner ear through the oval window , a flexible membrane separating the air-filled middle ear from the fluid-filled inner ear. The round window , another flexible membrane, allows for the smooth displacement of the inner ear fluid caused by the entering sound waves. The inner ear consists of the cochlea , which is a spiral-shaped, fluid-filled tube. It is divided lengthwise by the organ of Corti , which
6930-467: The light, leaving slow-moving bats at a disadvantage. Another example is harbor seals eating juvenile salmon that moved down a river lit by nearby artificial lighting. Once the lights were turned off, predation levels decreased. Many diurnal prey species forced into being nocturnal are susceptible to nocturnal predators and those species with poor nocturnal eyesight often bear the brunt of the cost. The increasing amount of habitat destruction worldwide as
7029-472: The longest land migration of mammals in Africa. When migrating, they appear to rely on some memory of the locations where foraging conditions were best and may predict conditions months after their arrival. Plains zebras are more water-dependent and live in moister environments than other species. They usually can be found 10–12 km (6.2–7.5 mi) from a water source. Grévy's zebras can survive almost
7128-423: The lower light levels at night. More specifically, they have been found to have a larger cornea relative to their eye size than diurnal creatures to increase their visual sensitivity : in the low-light conditions. Nocturnality helps wasps , such as Apoica flavissima , avoid hunting in intense sunlight. Diurnal animals, including humans (except for night owls ), squirrels and songbirds, are active during
7227-408: The majority of the day when temperatures are warmer and are mainly active at night. They will only come out during the day if there are humid and cool conditions. Many plant species native to arid biomes have adapted so that their flowers only open at night when the sun's intense heat cannot wither and destroy their moist, delicate blossoms. These flowers are pollinated by bats, another creature of
7326-494: The many nocturnal species kept as ( exotic ) pets. Cats have adapted to domestication so that each individual, whether stray alley cat or pampered housecat, can change their activity level at will, becoming nocturnal or diurnal in response to their environment or the routine of their owners. Cats normally demonstrate crepuscular behavior, bordering nocturnal, being most active in hunting and exploration at dusk and dawn. Hearing (sense) Hearing , or auditory perception ,
7425-411: The most recent common ancestor of the equines within a range of 4.0 to 4.5 mya. Horses split from asses and zebras around this time and equines colonised Eurasia and Africa around 2.1–3.4 mya. Zebras and asses diverged from each other close to 2 mya. The mountain zebra diverged from the other species around 1.6 mya and the plains and Grévy's zebra split 1.4 mya. A 2017 mitochondrial DNA study placed
7524-528: The mountain zebra as vulnerable and the plains zebra as near-threatened . The quagga ( E. quagga quagga ), a type of plains zebra, was driven to extinction in the 19th century. Nevertheless, zebras can be found in numerous protected areas. The English name "zebra" derives from Italian , Spanish or Portuguese . Its origins may lie in the Latin equiferus , meaning "wild horse". Equiferus appears to have entered into Portuguese as ezebro or zebro , which
7623-427: The night time to prey on species that are used to avoiding diurnal predators. Some nocturnal fish species will use the moonlight to prey on zooplankton species that come to the surface at night. Some species have developed unique adaptations that allow them to hunt in the dark. Bats are famous for using echolocation to hunt down their prey, using sonar sounds to capture them in the dark. Another reason for nocturnality
7722-427: The night. Climate-change and the change in global temperatures has led to an increasing amount of diurnal species to push their activity patterns closer towards crepuscular or fully nocturnal behavior. This adaptive measure allows species to avoid the heat of the day, without having to leave that particular habitat. The exponential increase in human expansion and technological advances in the last few centuries has had
7821-497: The ones that have lived in the group longest. While traveling, the most dominant females and their offspring lead the group, followed by the next most dominant. The family stallion trails behind. Young of both sexes leave their natal groups as they mature; females are usually herded by outside males to become part of their harems. In the more arid-living Grévy's zebras, adults have more fluid associations and adult males establish large territories , marked by dung piles, and mate with
7920-591: The plains and mountain zebra, though it is possible that these are infertile due to the difference in chromosome numbers between the two species. Captive zebras have been bred with horses and donkeys ; these are known as zebroids . A zorse is a cross between a zebra and a horse; a zonkey, between a zebra and a donkey; and a zoni, between a zebra and a pony . Zebroids are often born sterile with dwarfism . As with all wild equines, zebras have barrel-chested bodies with tufted tails, elongated faces and long necks with long, erect manes . Their thin legs are each supported by
8019-581: The plains zebra. E. capensis , known as the Cape zebra, appeared around 2 mya and lived throughout southern and eastern Africa. Non-African equines that may have been basal to zebras include E. sansaniensis of Eurasia (circa 2.5 mya) and E. namadicus (circa 2.5 mya) and E. sivalensis (circa 2.0 mya) of the Indian subcontinent. Fertile hybrids have been reported in the wild between plains and Grévy's zebra. Hybridisation has also been recorded between
8118-521: The pregnant mare. With their distinctive black-and-white stripes, zebras are among the most recognizable mammals. They have been associated with beauty and grace, with naturalist Thomas Pennant describing them in 1781 as "the most elegant of quadrupeds". Zebras have been popular in photography, with some wildlife photographers describing them as the most photogenic animal. They have become staples in children's stories and wildlife-themed art, such as depictions of Noah's Ark . In children's alphabet books ,
8217-483: The sound of buzzing wasps, thus warning them of the presence of natural enemies. Some insects possess a tympanal organ . These are "eardrums", that cover air filled chambers on the legs. Similar to the hearing process with vertebrates, the eardrums react to sonar waves. Receptors that are placed on the inside translate the oscillation into electric signals and send them to the brain. Several groups of flying insects that are preyed upon by echolocating bats can perceive
8316-474: The sound to the brainstem . The sound information from the cochlea travels via the auditory nerve to the cochlear nucleus in the brainstem . From there, the signals are projected to the inferior colliculus in the midbrain tectum . The inferior colliculus integrates auditory input with limited input from other parts of the brain and is involved in subconscious reflexes such as the auditory startle response . The inferior colliculus in turn projects to
8415-401: The source of a sound. Unlike horses, zebras and asses have chestnut callosities present only on their front legs. In contrast to other living equines, zebras have longer front legs than back legs. Diagnostic traits of the zebra skull include: its relatively small size with a straight dorsal outline, protruding eye sockets, narrower rostrum, less conspicuous postorbital bar , separation of
8514-581: The species is promiscuous . Zebras communicate with various vocalisations, body postures and facial expressions. Social grooming strengthens social bonds in plains and mountain zebras. Zebras' dazzling stripes make them among the most recognizable mammals. They have been featured in art and stories in Africa and beyond. Historically, they have been highly sought by exotic animal collectors, but unlike horses and donkeys , zebras have never been completely domesticated . The International Union for Conservation of Nature (IUCN) lists Grévy's zebra as endangered ,
8613-416: The stripes appear at eight months, but the patterns may be determined at three to five weeks. For each species there is a point in embryonic development where the stripes are perpendicular to the dorsal line and spaced 0.4 mm (0.016 in) apart. However, this happens at three weeks of development for the plains zebra, four weeks for the mountain zebra, and five for Grévy's zebra. The difference in timing
8712-525: The subject of folk tales , some of which involve it being scorched by fire. The Maasai proverb "a man without culture is like a zebra without stripes" has become popular in Africa. The San people connected zebra stripes with water, rain and lightning, and water spirits were conceived of having these markings. For the Shona people , the zebra is a totem animal and is glorified in a poem as an "iridescent and glittering creature". Its stripes have symbolised
8811-411: The subject of humour and satire, being referred to as "The Queen's Ass", and was the subject of an oil painting by George Stubbs in 1763. The zebra also gained a reputation for being ill-tempered and kicked at visitors. In 1882, Ethiopia sent a zebra to French president Jules Grévy , and the species it belonged to was named in his honour. Attempts to domesticate zebras were largely unsuccessful. It
8910-639: The three living species, some fossil zebras and relatives have also been identified. Equus koobiforensis is an early equine basal to zebras found in the Shungura Formation , Ethiopia and the Olduvai Gorge , Tanzania , and dated to around 2.3 mya. E. oldowayensis is identified from remains in Olduvai Gorge dating to 1.8 mya. Fossil skulls of E. mauritanicus from Algeria which date to around 1 mya appears to show affinities with
9009-699: The timing of their movement for example. On a day-to-day basis, species can see significant changes in their internal temperatures, their general movement, feeding and body mass. These small scale changes can eventually lead to a population decline, as well as hurting local trophic levels and interconnecting species. Some typically diurnal species have even become crepuscular or nocturnal as a result of light pollution and general human disturbance. There have been documented effects of light pollution on reproductive cycles and factors in different species. It can affect mate choice , migration to breeding grounds, and nest site selection. In male green frogs , artificial light causes
9108-506: The ultrasound emissions this way and reflexively practice ultrasound avoidance . Zebra † E. capensis E. grevyi † E. koobiforensis † E. mauritanicus † E. oldowayensis E. quagga E. zebra Zebras ( US : / ˈ z iː b r ə z / , UK : / ˈ z ɛ b r ə z , ˈ z iː -/ ) (subgenus Hippotigris ) are African equines with distinctive black-and-white striped coats . There are three living species: Grévy's zebra ( Equus grevyi ),
9207-505: The union of male and female and at the ruined city of Great Zimbabwe , zebra stripes decorate what is believed to be a domba , a school meant to prepare girls for adulthood. In the Shona language , the name madhuve means "woman/women of the zebra totem" and is a name for girls in Zimbabwe . The plains zebra is the national animal of Botswana and zebras have been depicted on stamps during colonial and post-colonial Africa. For people of
9306-463: The upper, less nutritious grass canopy and preparing the way for more specialised grazers like wildebeest , which depend on shorter and more nutritious grasses below. Zebras are preyed on mainly by lions. Leopards , cheetahs , spotted hyenas , brown hyenas and wild dogs pose less of a threat to adults. Biting and kicking are a zebra's defense tactics. When threatened by lions, zebras flee, and when caught they are rarely effective in fighting off
9405-498: The user to measure hearing thresholds at different frequencies ( audiogram ). Despite possible errors in measurements, hearing loss can be detected. There are several different types of hearing loss: conductive hearing loss , sensorineural hearing loss and mixed types. Recently, the term of Aural Diversity has come into greater use, to communicate hearing loss and differences in a less negatively-associated term. There are defined degrees of hearing loss: Hearing protection
9504-408: The vibrations from the eardrum into the inner ear, the cochlea . The purpose of the middle ear ossicles is to overcome the impedance mismatch between air waves and cochlear waves, by providing impedance matching . Also located in the middle ear are the stapedius muscle and tensor tympani muscle , which protect the hearing mechanism through a stiffening reflex. The stapes transmits sound waves to
9603-514: The zoologist Walter Rothschild trained some zebras to draw a carriage in England, which he drove to Buckingham Palace to demonstrate that it can be done. However, he did not ride on them knowing that they were too small and aggressive. In the early 20th century, German colonial officers in East Africa tried to use zebras for both driving and riding, with limited success. As of 2016–2019,
9702-642: Was originally used for a legendary equine in the wilds of the Iberian Peninsula during the Middle Ages. In 1591, Italian explorer Filippo Pigafetta recorded "zebra" being used to refer to the African animals by Portuguese visitors to the continent. In ancient times, the zebra was called hippotigris ("horse tiger") by the Greeks and Romans . The word zebra was traditionally pronounced with
9801-524: Was probably vulnerable to extinction due to its restricted range, and because they were easy to find in large groups. The last known wild quagga died in 1878. The last captive quagga, a female in Amsterdam's Natura Artis Magistra zoo, lived there from 9 May 1867 until it died on 12 August 1883. The Cape mountain zebra , a subspecies of mountain zebra, nearly went extinct due to hunting and habitat destruction, with less than 50 individuals left by
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