The impala or rooibok (''Aepyceros melampus'') is a medium-sized

antelope The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia. Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mammals ...

found in

eastern Eastern may refer to: Transportation *China Eastern Airlines, a current Chinese airline based in Shanghai *Eastern Air, former name of Zambia Skyways *Eastern Air Lines, a defunct American airline that operated from 1926 to 1991 *Eastern Air Li ...

and

southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of ...

. The

only Only may refer to: Music Albums * ''Only'' (album), by Tommy Emmanuel, 2000 * ''The Only'', an EP by Dua Lipa, 2017 Songs * "Only" (Anthrax song), 1993 * "Only" (Nine Inch Nails song), 2005 * "Only" (Nicki Minaj song), 2014 * "The Only", by ...

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

member of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

'' Aepyceros'' and tribe Aepycerotini, it was first described to European audiences by German zoologist

Hinrich Lichtenstein Martin Hinrich Carl Lichtenstein (10 January 1780 – 2 September 1857) was a German physician, explorer, botanist and zoologist. Biography Born in Hamburg, Lichtenstein was the son of Anton August Heinrich Lichtenstein. He studied medicine ...

in 1812. Two

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

are recognised—the common impala, and the larger and darker black-faced impala. The impala reaches at the shoulder and weighs . It features a glossy, reddish brown

coat A coat typically is an outer garment for the upper body as worn by either gender for warmth or fashion. Coats typically have long sleeves and are open down the front and closing by means of buttons, zippers, hook-and-loop fasteners, toggles, a ...

. The male's slender,

lyre The lyre () is a stringed musical instrument that is classified by Hornbostel–Sachs as a member of the lute-family of instruments. In organology, a lyre is considered a yoke lute, since it is a lute in which the strings are attached to a yoke ...

-shaped

horns Horns or The Horns may refer to: * Plural of Horn (instrument), a group of musical instruments all with a horn-shaped bells * The Horns (Colorado), a summit on Cheyenne Mountain * ''Horns'' (novel), a dark fantasy novel written in 2010 by Joe Hill ...

are long. Active mainly during the day, the impala may be

gregarious Sociality is the degree to which individuals in an animal population tend to associate in social groups (gregariousness) and form cooperative societies. Sociality is a survival response to evolutionary pressures. For example, when a mother wasp ...

territorial A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...

depending upon the climate and geography. Three distinct social groups can be observed: the territorial males, bachelor herds and female herds. The impala is known for two characteristic leaps that constitute an anti-

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

strategy.

Browsers Browse, browser or browsing may refer to: Programs * Web browser, a program used to access the World Wide Web *Code browser, a program for navigating source code * File browser or file manager, a program used to manage files and related objects * ...

as well as grazers, impala feed on

monocot Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of ...

dicot The dicotyledons, also known as dicots (or, more rarely, dicotyls), are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, t ...

forb A forb or phorb is an herbaceous flowering plant that is not a graminoid (grass, sedge, or rush). The term is used in biology and in vegetation ecology, especially in relation to grasslands and understory. Typically these are dicots without woo ...

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

s and

acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus na ...

pods (whenever available). An annual, three-week-long rut takes place toward the end of the wet season, typically in May. Rutting males fight over dominance, and the victorious male courts female in

oestrus The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous ...

Gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregna ...

lasts six to seven months, following which a single calf is born and immediately concealed in cover. Calves are suckled for four to six months; young males—forced out of the all-female groups—join bachelor herds, while females may stay back. The impala is found in woodlands and sometimes on the interface (

ecotone An ecotone is a transition area between two biological communities, where two communities meet and integrate. It may be narrow or wide, and it may be local (the zone between a field and forest) or regional (the transition between forest and gras ...

) between woodlands and

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

hs; it inhabits places near water. While the black-faced impala is confined to southwestern

Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

and

Kaokoland Kaokoland was an administrative unit and a ''bantustan'' in northern South West Africa (now Namibia). Established during the apartheid era, it was intended to be a self-governing homeland of the OvaHimba, but an actual government was never e ...

in northwestern

Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

, the common impala is widespread across its range and has been reintroduced in

Gabon Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north ...

and southern Africa. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(IUCN) classifies the impala as a

species of least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

; the black-faced subspecies has been classified as a

vulnerable species A vulnerable species is a species which has been Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, ...

, with fewer than 1,000 individuals remaining in the wild as of 2008.

Etymology

The first attested English name, in 1802, was palla or pallah, from the

Tswana Tswana may refer to: * Tswana people, the Bantu speaking people in Botswana, South Africa, Namibia, Zimbabwe, Zambia, and other Southern Africa regions * Tswana language, the language spoken by the (Ba)Tswana people * Bophuthatswana, the former ba ...

' 'red antelope'; the name ''impala'', also spelled ''impalla'' or ''mpala'', is first attested in 1875, and is directly from Zulu. Its

Afrikaans Afrikaans (, ) is a West Germanic language that evolved in the Dutch Cape Colony from the Dutch vernacular of Holland proper (i.e., the Hollandic dialect) used by Dutch, French, and German settlers and their enslaved people. Afrikaans gra ...

name, ' 'red buck', is also sometimes used in English. The

scientific Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for ...

generic name ''Aepyceros'' ( ‘high-horned’) comes from

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

(', 'high, steep') + (', 'horn'); the specific name ''melampus'' ( ‘black-foot’) from (', 'black') + (', 'foot').

Taxonomy and evolution

The impala is the sole member of the genus ''Aepyceros'' and belongs to the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Bovidae The Bovidae comprise the biological family of cloven-hoofed, ruminant mammals that includes cattle, bison, buffalo, antelopes, and caprines. A member of this family is called a bovid. With 143 extant species and 300 known extinct species, ...

. It was first described by German zoologist Martin Hinrich Carl Lichtenstein in 1812. In 1984, palaeontologist

Elisabeth Vrba Elisabeth S. Vrba (born 17 May 1942) is a paleontologist at Yale University who developed the turnover-pulse hypothesis. Education Vrba earned her Ph.D. in Zoology and Palaeontology at the University of Cape Town, in 1974. Vrba studied zoology ...

opined that the impala is a

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to the

alcelaphines The subfamily Alcelaphinae or tribe Alcelaphini of the family Bovidae contains wildebeest, hartebeest, bonteboks, and several similar species. Depending on the classification, there are 6–10 species placed in four genera, although ''Beatragus' ...

, given its resemblance to the

hartebeest The hartebeest (; ''Alcelaphus buselaphus''), also known as kongoni or kaama, is an African antelope. It is the only member of the genus ''Alcelaphus''. Eight subspecies have been described, including two sometimes considered to be indepen ...

. A 1999

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

study by Alexandre Hassanin (of the National Centre for Scientific Research, Paris) and colleagues, based on

mitochondrial A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is use ...

and

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: * Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear space *Nuclear ...

analyses, showed that the impala forms a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

with the suni (''Neotragus moschatus''). This clade is sister to another formed by the

bay duiker The bay duiker (''Cephalophus dorsalis''), also known as the black-striped duiker and the black-backed duiker, is a forest-dwelling duiker native to western and southern Africa. It was first described by British zoologist John Edward Gray in 18 ...

(''Cephalophus dorsalis'') and the

klipspringer The klipspringer (; ''Oreotragus oreotragus'') is a small antelope found in eastern and southern Africa. The sole member of its genus and subfamily/tribe, the klipspringer was first described by German zoologist Eberhard August Wilhelm von Zimm ...

(''Oreotragus oreotragus''). An

rRNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosoma ...

and β-spectrin nuclear sequence analysis in 2003 also supported an association between ''Aepyceros'' and '' Neotragus''. The following cladogram is based on the 1999 study: Up to six

have been described, although only two are generally recognised on the basis of mitochondrial data. Though morphologically similar, the subspecies show a significant

genetic distance Genetic distance is a measure of the genetic divergence between species or between populations within a species, whether the distance measures time from common ancestor or degree of differentiation. Populations with many similar alleles have sma ...

between them, and no hybrids between them have been reported. * ''A. m. melampus'' Lichtenstein, 1812: Known as the common impala, it occurs across eastern and southern Africa. The range extends from central

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

and westward into southeastern

Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

. * ''A. m. petersi''

Bocage Bocage (, ) is a terrain of mixed woodland and pasture characteristic of parts of Northern France, Southern England, Ireland, the Netherlands and Northern Germany, in regions where pastoral farming is the dominant land use. ''Bocage'' may als ...

, 1879: Known as the black-faced impala, it is restricted to southwestern Africa, occurring in northwestern

and southwestern Angola. According to Vrba, the impala evolved from an alcelaphine ancestor. She noted that while this ancestor has diverged at least 18 times into various morphologically different forms, the impala has continued in its basic form for at least five million years. Several

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

species have been discovered, including '' A. datoadeni'' from the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

. The oldest fossil discovered suggests its ancient ancestors were slightly smaller than the modern form, but otherwise very similar in all aspects to the latter. This implies that the impala has efficiently adapted to its environment since prehistoric times. Its gregarious nature, variety in diet, positive population trend, defence against

tick Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...

s and

symbiotic Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...

relationship with the tick-feeding

oxpecker The oxpeckers are two species of bird which make up the genus ''Buphagus'', and family Buphagidae. The oxpeckers were formerly usually treated as a subfamily, Buphaginae, within the starling family, Sturnidae, but molecular phylogenetic studi ...

s could have played a role in preventing major changes in morphology and behaviour.

Description

The impala is a medium-sized, slender

similar to the

kob The kob (''Kobus kob'') is an antelope found across Central Africa and parts of West Africa and East Africa. Together with the closely related reedbucks, waterbucks, lechwe, Nile lechwe, and puku, it forms the Reduncinae tribe. Found along ...

Grant's gazelle Grant's gazelle (''Nanger granti'') is a species of gazelle distributed from northern Tanzania to South Sudan and Ethiopia, and from the Kenyan coast to Lake Victoria. Its Swahili name is ''swala granti''. The head-and-body length is around . Males reach approximately at the shoulder, while females are tall. Males typically weigh and females .

Sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

, females are hornless and smaller than males. Males grow slender, lyre-shaped horns long. The horns, strongly ridged and divergent, are circular in section and hollow at the base. Their arch-like structure allows interlocking of horns, which helps a male throw off his opponent during fights; horns also protect the skull from damage. The glossy coat of the impala shows two-tone colourationthe reddish brown back and the tan flanks; these are in sharp contrast to the white underbelly. Facial features include white rings around the eyes and a light chin and

snout A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, rostrum, or proboscis. The wet furless surface around the nostrils of the nose of many mammals is c ...

. The ears, long, are tipped with black. Black streaks run from the buttocks to the upper hindlegs. The bushy white tail, long, features a solid black stripe along the midline. The impala's colouration bears a strong resemblance to the

gerenuk The gerenuk (; so, garanuug; ''Litocranius walleri''), also known as the giraffe gazelle, is a long-necked antelope found in parts of East Africa. The sole member of the genus ''Litocranius'', the gerenuk was first described by the naturalist ...

, which has shorter horns and lacks the black thigh stripes of the impala. The impala has

scent gland Scent gland are exocrine glands found in most mammals. They produce semi-viscous secretions which contain pheromones and other semiochemical compounds. These odor-messengers indicate information such as status, territorial marking, mood, and sexu ...

s covered by a black tuft of hair on the hindlegs.

Sebaceous gland A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest number ...

s concentrated on the forehead and dispersed on the torso of dominant males are most active during the mating season, while those of females are only partially developed and do not undergo seasonal changes. There are four

nipples The nipple is a raised region of tissue on the surface of the breast from which, in females, milk leaves the breast through the lactiferous ducts to feed an infant. The milk can flow through the nipple passively or it can be ejected by smooth mu ...

. Of the subspecies, the black-faced impala is significantly larger and darker than the common impala;

melanism The term melanism refers to black pigment and is derived from the gr, μελανός. Melanism is the increased development of the dark-colored pigment melanin in the skin or hair. Pseudomelanism, also called abundism, is another variant of pi ...

is responsible for the black colouration. Distinctive of the black-faced impala is a dark stripe, on either side of the nose, that runs upward to the eyes and thins as it reaches the forehead. Other differences include the larger black tip on the ear, and a bushier and nearly 30% longer tail in the black-faced impala. The impala has a special dental arrangement on the front lower jaw similar to the

toothcomb A toothcomb (also tooth comb or dental comb) is a dental structure found in some mammals, comprising a group of front teeth arranged in a manner that facilitates grooming, similar to a hair comb. The toothcomb occurs in lemuriform primates ( ...

seen in strepsirrhine primates, which is used during

allogrooming Social grooming is a behavior in which social animals, including humans, clean or maintain one another's body or appearance. A related term, allogrooming, indicates social grooming between members of the same species. Grooming is a major soci ...

to comb the fur on the head and the neck and remove

ectoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

Ecology and behaviour

The impala is diurnal (active mainly during the day), though activity tends to cease during the hot midday hours; they feed and rest at night. Three distinct social groups can be observedthe

males, bachelor herds and female herds. The territorial males hold territories where they may form

harems Harem (Persian: حرمسرا ''haramsarā'', ar, حَرِيمٌ ''ḥarīm'', "a sacred inviolable place; harem; female members of the family") refers to domestic spaces that are reserved for the women of the house in a Muslim family. A hare ...

of females; territories are demarcated with urine and faeces and defended against juvenile or male intruders. Bachelor herds tend to be small, with less than 30 members. Individuals maintain distances of from one another; while young and old males may interact, middle-aged males generally avoid one another except to spar. Female herds vary in size from 6 to 100; herds occupy

home range A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He ...

s of . The mother–calf bond is weak, and breaks soon after weaning; juveniles leave the herds of their mothers to join other herds. Female herds tend to be loose and have no obvious leadership. Allogrooming is an important means of social interaction in bachelor and female herds; in fact, the impala appears to be the only

ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, cam ...

to display self-grooming as well as allogrooming. In allogrooming, females typically groom related impalas, while males associate with unrelated ones. Each partner grooms the other six to twelve times. Impala-stotting

Social behaviour is influenced by the climate and geography; as such, the impala are territorial at certain times of the year and gregarious at other times, and the length of these periods can vary broadly among populations. For instance, populations in southern Africa display territorial behaviour only during the few months of the rut, whereas in eastern African populations, territoriality is relatively minimal despite a protracted mating season. Moreover, territorial males often tolerate bachelors, and may even alternate between bachelorhood and territoriality at different times of the year. A study of impala in the

Serengeti National Park The Serengeti National Park is a large national park in northern Tanzania that stretches over . It is located entirely in eastern Mara Region and north east portion of Simiyu Region and contains over of virgin savanna. The park was established in ...

showed that in 94% of the males, territoriality was observed for less than four months. The impala is an important prey species for several

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

s, such as

cheetah The cheetah (''Acinonyx jubatus'') is a large cat native to Africa and central Iran. It is the fastest land animal, estimated to be capable of running at with the fastest reliably recorded speeds being , and as such has evolved specialized ...

leopards The leopard (''Panthera pardus'') is one of the five extant species in the genus '' Panthera'', a member of the cat family, Felidae. It occurs in a wide range in sub-Saharan Africa, in some parts of Western and Central Asia, Southern Russia, ...

wild dogs Wild Dogs is an American heavy metal band from Portland, Oregon, formed loosely in 1981 by original members Jeff Mark, Danny Kurth, Matt McCourt, and Pete Holmes. The band has since released six albums, three live albums and one DVD. Wild Dogs ...

and

lion The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'' native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphi ...

s. The antelope displays two characteristic leapsit can jump up to , over vegetation and even other impala, covering distances of up to ; the other type of leap involves a series of jumps in which the animal lands on its forelegs, moves its hindlegs mid-air in a kicking fashion, lands on all fours (

stotting Stotting (also called pronking or pronging) is a behavior of quadrupeds, particularly gazelles, in which they spring into the air, lifting all four feet off the ground simultaneously. Usually, the legs are held in a relatively stiff position. Ma ...

) and then rebounds. It leaps in either manner in different directions, probably to confuse predators. At times, the impala may also conceal itself in vegetation to escape the eye of the predator. The most prominent vocalisation is the loud roar, delivered through one to three loud snorts with the mouth closed, followed by two to ten deep grunts with the mouth open and the chin and tail raised; a typical roar can be heard up to away. Scent gland secretions identify a territorial male. Impalas are sedentary; adult and middle-aged males, in particular, can hold their territories for years.

Parasites

Common

ixodid The Ixodidae are the family of hard ticks or scale ticks, one of the three families of ticks, consisting of over 700 species. They are known as 'hard ticks' because they have a scutum or hard shield, which the other major family of ticks, the 'sof ...

ticks collected from impala include '' Amblyomma hebraeum'', '' Boophilus decoloratus'', ''

Hyalomma marginatum ''Hyalomma marginatum'' is a hard-bodied tick found on birds including the pale crag martin. This tick has been implicated in the transmission of Bahig virus, a pathogenic arbovirus previously thought to be transmitted only by mosquitoes. The ...

'', '' Ixodes cavipalpus'', ''

Rhipicephalus appendiculatus ''Rhipicephalus appendiculatus'', the brown ear tick, is a hard tick found in Africa where it spreads the parasite ''Theileria parva'', the cause of East Coast fever East Coast fever, also known as theileriosis, is a disease of cattle which o ...

'' and '' R. evertsi''. In

Zimbabwe Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and Mozam ...

, heavy infestation by ticks such as ''R. appendiculatus'' has proved to be a major cause behind the high mortality of ungulates, as they can lead to

tick paralysis Tick paralysis is the only tick-borne disease that is not caused by an infectious organism. The illness is caused by a neurotoxin produced in the tick's salivary gland. After prolonged attachment, the engorged tick transmits the toxin to its host. ...

. Impala have special adaptations for grooming, such as their characteristic dental arrangement, to manage ticks before they engorge; however, the extensive grooming needed to keep the tick load under control involves the risk of dehydration during summer, lower vigilance against predators and gradual wearing out of the teeth. A study showed that impala adjust the time devoted to grooming and the number of grooming bouts according to the seasonal prevalence of ticks. Impala are symbiotically related to

s, which feed on ticks from those parts of the antelope's body which the animal cannot access by itself (such as the ears, neck, eyelids, forehead and underbelly). The impala is the smallest ungulate with which oxpeckers are associated. In a study it was observed that oxpeckers selectively attended to impala despite the presence of other animals such as

Coke's hartebeest Coke's hartebeest (''Alcelaphus buselaphus cokii'') or ''Kongoni'' is a large migratory antelope that is native to Kenya and Tanzania. It can breed with Lelwel hartebeest to produce a hybrid known as the Kenya Highland hartebeest (''Alcelaphus ...

, Grant's gazelle,

Thomson's gazelle Thomson's gazelle (''Eudorcas thomsonii'') is one of the best known species of gazelles. It is named after explorer Joseph Thomson and is sometimes referred to as a "tommie". It is considered by some to be a subspecies of the red-fronted gazelle a ...

and

topi ''Damaliscus lunatus jimela'' is a subspecies of topi, and is usually just called a topi. It is a highly social and fast type of antelope found in the savannas, semi-deserts, and floodplains of sub-Saharan Africa. Names The word ''tope'' or '' ...

. A possible explanation for this could be that because the impala inhabits woodlands (which can have a high density of ticks), the impala could have greater mass of ticks per unit area of the body surface. Another study showed that the oxpeckers prefer the ears over other parts of the body, probably because these parts show maximum tick infestation. The bird has also been observed to perch on the

udders An udder is an organ formed of two or four mammary glands on the females of dairy animals and ruminants such as cattle, goats, and sheep. An udder is equivalent to the breast in primates and elephantine pachyderms. The udder is a single mass ha ...

of a female and pilfer its

milk Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digestion, digest solid food. Immune factors and immune ...

Lice Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a result o ...

recorded from impala include ''

Damalinia aepycerus ''Damalinia'' is a genus of lice belonging to the family Trichodectidae Trichodectidae is a family of louse in the suborder Ischnocera. Its species are parasites of mammals. The following 19 genera are recognized: * ''Bovicola ''Bovicola'' ...

'', '' D. elongata'', ''

Linognathus aepycerus ''Linognathus'' is a genus of lice belonging to the family Linognathidae. The species of this genus are found in Eurasia, Africa and Northern America. Species: * ''Linognathus aepycerus'' Bedford, 1936 * ''Linognathus africanus'' Kellogg & Pai ...

'' and '' L. nevilli''; in a study,

ivermectin Ivermectin (, '' EYE-vər-MEK-tin'') is an antiparasitic drug. After its discovery in 1975, its first uses were in veterinary medicine to prevent and treat heartworm and acariasis. Approved for human use in 1987, today it is used to treat inf ...

(a medication against parasites) was found to have an effect on ''Boophilus decoloratus'' and ''Linognathus'' species, though not on ''Damalinia'' species. In a study of impala in South Africa, the number of

worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete wor ...

s in juveniles showed an increase with age, reaching a peak when impala turned a year old. This study recorded worms of genera such as '' Cooperia'', '' Cooperoides'', ''

Fasciola ''Fasciola'', commonly known as the liver fluke, is a genus of parasitic trematodes. There are two species within the genus ''Fasciola'': ''Fasciola'' ''hepatica'' and ''Fasciola'' ''gigantica'', as well as hybrids between the two species. Bot ...

'', ''

Gongylonema ''Gongylonema'' is a genus of thread-like nematode that was described by Molin in 1857. It is the only currently valid genus in the family Gongylonematidae, though the mysterious '' Spiruroides'' – usually placed in the Subuluridae, which are ...

''. ''

Haemonchus ''Haemonchus'' is a genus of nematodes belonging to the family Trichostrongylidae. They are abomasal parasites that cause anemia, followed by white eye disease. The genus has cosmopolitan distribution. Species: *''Haemonchus contortus '' ...

'', '' Impalaia'', ''

Longistrongylus ''Longistrongylus'' is a genus of nematodes belonging to the family Trichostrongylidae Trichostrongylidae is a family of nematode in the suborder Strongylida. Genera Genera: * '' Africanastrongylus'' Hoberg, Abrams & Ezenwa, 2008 * '' Amidosto ...

'' and ''

Trichostrongylus ''Trichostrongylus'' species are nematodes (round worms), which are ubiquitous among herbivores worldwide, including cattle, sheep, donkeys, goats, deer, and rabbits.Garcia LS, editor. Diagnostic Medical Parasitology. 5 ed. Washington, DC: ASM Pr ...

''; some of these showed seasonal variations in density. Impala show high frequency of

defensive behaviour Deimatic behaviour or startle display means any pattern of bluffing behaviour in an animal that lacks strong defences, such as suddenly displaying conspicuous eyespots, to scare off or momentarily distract a predator, thus giving the prey anim ...

s towards flying insects. This is probably the reason for Vale 1977 and Clausen et al 1998 only finding trace levels of feeding by ''Glossina'' (

tsetse fly Tsetse ( , or ) (sometimes spelled tzetze; also known as tik-tik flies), are large, biting flies that inhabit much of tropical Africa. Tsetse flies include all the species in the genus ''Glossina'', which are placed in their own family, Glo ...

) upon impala. ''

Theileria ''Theileria'' is a genus of parasites that belongs to the phylum Apicomplexa, and is closely related to ''Plasmodium''. Two ''Theileria'' species, ''T. annulata'' and ''T. parva'', are important cattle parasites. ''T. annulata'' causes tropical ...

'' of impala in

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

are not cross infectious to

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...

: Grootenhuis et al 1975 were not able to induce cattle infection and Fawcett et al 1987 did not find it naturally occurring.

Diet

Impala

browse Browsing is a kind of orienting strategy. It is supposed to identify something of relevance for the browsing organism. When used about human beings it is a metaphor taken from the animal kingdom. It is used, for example, about people browsing o ...

as well as graze; either may predominate, depending upon the availability of resources. The diet comprises

s, fruits and ''

'' pods (whenever available). Impala prefer places close to water sources, and resort to succulent vegetation if water is scarce. An analysis showed that the diet of impala is composed of 45% monocots, 45% dicots and 10% fruits; the proportion of grasses in the diet increases significantly (to as high as 90%) after the first rains, but declines in the

dry season The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The te ...

. Browsing predominates in the late wet and dry season, and diets are nutritionally poor in the mid-dry season, when impala feed mostly on woody dicots. Another study showed that the dicot proportion in the diet is much higher in bachelors and females than in territorial males. Impala feed on soft and nutritious grasses such as ''

Digitaria macroblephara ''Digitaria'' is a genus of plants in the Poaceae, grass family native to tropical and warm temperate regions but can occur in tropical, subtropical, and cooler temperate regions as well. Common names include crabgrass, finger-grass, and fonio. ...

''; tough, tall grasses, such as ''

Heteropogon contortus ''Heteropogon contortus'' is a tropical, perennial tussock grass with a native distribution encompassing Southern Africa, southern Asia, Northern Australia, Oceania, and southwestern North America. The species has also become a naturalised weed i ...

'' and ''

Themeda triandra } ''Themeda triandra'' is a species of perennial tussock-forming grass widespread in Africa, Australia, Asia and the Pacific. In Australia it is commonly known as kangaroo grass and in East Africa and South Africa it is known as red grass and re ...

'', are typically avoided. Impala on the periphery of the herds are generally more vigilant against predators than those feeding in the centre; a foraging individual will try to defend the patch it is feeding on by lowering its head. A study revealed that time spent in foraging reaches a maximum of 75.5% of the day in the late dry season, decreases through the rainy season, and is minimal in the early dry season (57.8%).

Reproduction

Males are

sexually mature Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definitio ...

by the time they are a year old, though successful mating generally occurs only after four years. Mature males start establishing territories and try to gain access to females. Females can conceive after they are a year and a half old;

lasts for 24 to 48 hours, and occurs every 12–29 days in non-pregnant females. The annual three-week-long rut (breeding season) begins toward the end of the

wet season The wet season (sometimes called the Rainy season) is the time of year when most of a region's average annual rainfall occurs. It is the time of year where the majority of a country's or region's annual precipitation occurs. Generally, the sea ...

, typically in May.

Gonad A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sper ...

al growth and

hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...

production in males begin a few months before the breeding season, resulting in greater aggressiveness and territoriality. The

bulbourethral gland The bulbourethral glands or Cowper's glands (named for English anatomist William Cowper) are two small exocrine glands in the reproductive system of many male mammals (of all domesticated animals, they are absent only in dogs). They are homolog ...

s are heavier,

testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testes and prostate, as well as promoting secondar ...

levels are nearly twice as high in territorial males as in bachelors, and the neck of a territorial male tends to be thicker than that of a bachelor during the rut. Mating tends to take place between full moons. Rutting males fight over dominance, often giving out noisy roars and chasing one another; they walk stiffly and

display Display may refer to: Technology * Display device, output device for presenting information, including: ** Cathode ray tube, video display that provides a quality picture, but can be very heavy and deep ** Electronic visual display, output devi ...

their neck and horns. Males desist from feeding and allogrooming during the rut, probably to devote more time to garnering females in oestrus; the male checks the female's urine to ensure that she is in oestrus. On coming across such a female, the excited male begins the

courtship Courtship is the period wherein some couples get to know each other prior to a possible marriage. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marriage. A courtship may be an informal and private m ...

by pursuing her, keeping a distance of from her. The male flicks his tongue and may nod vigorously; the female allows him to lick her vulva, and holds her tail to one side. The male tries mounting the female, holding his head high and clasping her sides with his forelegs. Mounting attempts may be repeated every few seconds to every minute or two. The male loses interest in the female after the first copulation, though she is still active and can mate with other males. Gestation lasts six to seven months. Births generally occur in the midday; the female will isolate herself from the herd when labour pain begins. The perception that females can delay giving birth for an additional month if conditions are harsh may however not be realistic. A single calf is born, and is immediately concealed in cover for the first few weeks of its birth. The fawn then joins a nursery group within its mother's herd. Calves are suckled for four to six months; young males, forced out of the group, join bachelor herds, while females may stay back.

Distribution and habitat

Aepyceros melampus Impala in Tanzania 3490 Nevit

The impala inhabits woodlands due to its preference for shade; it can also be found on the interface (ecotone) between woodlands and savannahs. Places near water sources are preferred. In southern Africa, populations tend to be associated with ''

Colophospermum mopane ''Colophospermum mopane'', commonly called mopane, mopani, balsam tree, butterfly tree, or turpentine tree, is a tree in the legume family ( Fabaceae), that grows in hot, dry, low-lying areas, in elevation, in the far northern parts of southern ...

'' and ''Acacia'' woodlands. Habitat choices differ seasonally''

Acacia senegal ''Senegalia senegal'' (also known as ''Acacia senegal'') is a small thorny deciduous tree from the genus '' Senegalia'', which is known by several common names, including gum acacia, gum arabic tree, Sudan gum and Sudan gum arabic. In parts of I ...

'' woodlands are preferred in the wet season, and '' A. drepanolobium'' savannahs in the dry season. Another factor that could influence habitat choice is vulnerability to predators; impala tend to keep away from areas with tall grasses as predators could be concealed there. A study found that the reduction of woodland cover and creation of shrublands by the

African bush elephant The African bush elephant (''Loxodonta africana'') is one of two extant African elephant species and one of three extant elephant species. It is the largest living terrestrial animal, with bulls reaching a shoulder height of up to and a body ...

s has favoured impala population by increasing the availability of more dry season browse. Earlier, the '' Baikiaea'' woodland, which has now declined due to elephants, provided minimum browsing for impala. The newly formed '' Capparis'' shrubland, on the other hand, could be a key browsing habitat. Impala are generally not associated with

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

habitats; however, in

KwaZulu-Natal KwaZulu-Natal (, also referred to as KZN and known as "the garden province") is a province of South Africa that was created in 1994 when the Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu) and Natal Province were merged. It is locate ...

, impala have been recorded at altitudes of up to

above sea level Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

. The historical range of the impala – spanning across southern and eastern Africa – has remained intact to a great extent, although it has disappeared from a few places, such as

Burundi Burundi (, ), officially the Republic of Burundi ( rn, Repuburika y’Uburundi ; Swahili language, Swahili: ''Jamuhuri ya Burundi''; French language, French: ''République du Burundi'' ), is a landlocked country in the Great Rift Valley at the ...

. The range extends from central and southern Kenya and northeastern

Uganda }), is a landlocked country in East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territor ...

in the east to northern KwaZulu-Natal in the south, and westward up to Namibia and southern Angola. The black-faced impala is confined to southwestern Angola and

in northwestern Namibia; the status of this subspecies has not been monitored since the 2000s. The common impala has a wider distribution, and has been introduced in protected areas in

and across southern Africa.

Threats and conservation

Impala tracks The

International Union for Conservation of Nature and Natural Resources The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(IUCN) classifies the impala as a

overall. The black-faced impala, however, is classified as a

; as of 2008, fewer than 1,000 were estimated in the wild. Though there are no major threats to the survival of the common impala, poaching and natural calamities have significantly contributed to the decline of the black-faced impala. As of 2008, the population of the common impala has been estimated at around two million. According to some studies, translocation of the black-faced impala can be highly beneficial in its conservation. Around a quarter of the common impala populations occur in protected areas, such as the

Okavango Delta The Okavango Delta (or Okavango Grassland; formerly spelled "Okovango" or "Okovanggo") in Botswana is a swampy inland delta formed where the Okavango River reaches a tectonic trough at an altitude of 930–1,000 m in the central part of the en ...

(

Botswana Botswana (, ), officially the Republic of Botswana ( tn, Lefatshe la Botswana, label=Setswana, ), is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory being the Kalahar ...

);

Masai Mara Maasai Mara, also sometimes spelled Masai Mara and locally known simply as The Mara, is a large national game reserve in Narok, Kenya, contiguous with the Serengeti National Park in Tanzania. It is named in honor of the Maasai people, the ancest ...

and

Kajiado Kajiado is a town in Kajiado County, Kenya. The town is located south of Nairobi, along the Nairobi – Arusha highway ( A104 road). Kajiado has an urban population of 24,678 (2019 census). Local people are predominantly of the Maasai tribe. ...

(Kenya);

Kruger National Park Kruger National Park is a South African National Park and one of the largest game reserves in Africa. It covers an area of in the provinces of Limpopo and Mpumalanga in northeastern South Africa, and extends from north to south and from ea ...

(South Africa); the Ruaha and

s and

Selous Game Reserve The Selous Game Reserve, now renamed Nyerere National Park, is a protected area in southern Tanzania. It covers a total area of and has additional buffer zones. It was designated a UNESCO World Heritage Site in 1982 due to its wildlife diversity ...

(

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

);

Luangwa Valley The Luangwa River is one of the major tributaries of the Zambezi River, and one of the four biggest rivers of Zambia. The river generally floods in the rainy season (December to March) and then falls considerably in the dry season. It is one of ...

(

Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most cent ...

);

Hwange Hwange (formerly Wankie) is a town in Zimbabwe, located in Hwange District, in Matabeleland North Province, in northwestern Zimbabwe, close to the international borders with Botswana and Zambia. It lies approximately , by road, southeast of Vi ...

, Sebungwe and

Zambezi Valley The Zambezi River (also spelled Zambeze and Zambesi) is the fourth-longest river in Africa, the longest east-flowing river in Africa and the largest flowing into the Indian Ocean from Africa. Its drainage basin covers , slightly less than hal ...

(

). The rare black-faced impala has been introduced into private farms in Namibia and the

Etosha National Park Etosha National Park is a national park in northwestern Namibia and one of the largest national parks in Africa. It was proclaimed a game reserve in March 1907 in Ordinance 88 by the Governor of German South West Africa, Friedrich von Lindequist. ...

. Population densities vary largely from place to place; from less than one impala per square kilometre in

Mkomazi National Park Mkomazi National Park is located in northeastern Tanzania on the Kenyan border, in Kilimanjaro Region and Tanga Region. It was established as a game reserve in 1951 and upgraded to a national park in 2006. The park covers over , and is dominate ...

(Tanzania) to as high as 135 per square kilometre near

Lake Kariba Lake Kariba is the world's largest artificial lake and reservoir (water), reservoir by List of lakes by volume, volume. It lies upstream from the Indian Ocean, along the border between Zambia and Zimbabwe. Lake Kariba was filled between 1958 and ...

(Zimbabwe).

References

External links

Impala: Summary from the African Wildlife Foundation

ITIS Standard Report Page
{{Authority control Bovidae Antelopes of Sub-Saharan Africa Fauna of East Africa Mammals of Southern Africa Mammals described in 1812