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Clownfish or anemonefish are fishes from the subfamily Amphiprioninae in the family Pomacentridae. Thirty species of clownfish are recognized: one in the genus Premnas, while the remaining are in the genus Amphiprion. In the wild, they all form symbiotic mutualisms with sea anemones. Depending on the species, anemonefish are overall yellow, orange, or a reddish or blackish color, and many show white bars or patches. The largest can reach a length of 17 cm (6+¹⁄₂ in), while the smallest barely achieve 7–8 cm (2+³⁄₄–3+¹⁄₄ in).

Distribution and habitat

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Anemonefish are endemic to the warmer waters of the Indian Ocean, including the Red Sea, and Pacific Ocean, the Great Barrier Reef, Hawaii, USA, North America, Southeast Asia, Japan, and the Indo-Malaysian region. While most species have restricted distributions, others are widespread. Anemonefish typically live at the bottom of shallow seas in sheltered reefs or in shallow lagoons. No anemonefish are found in the Atlantic.^[1]

Diet

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Anemonefish are omnivorous and can feed on undigested food from their host anemones, and the fecal matter from the anemonefish provides nutrients to the sea anemone. Anemonefish primarily feed on small zooplankton from the water column, such as copepods and tunicate larvae, with a small portion of their diet coming from algae, with the exception of Amphiprion perideraion, which primarily feeds on algae.^[2][3]

Symbiosis and mutualism

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Anemonefish and sea anemones have a symbiotic, mutualistic relationship, each providing many benefits to the other. The individual species are generally highly host specific. The sea anemone protects the anemonefish from predators, as well as providing food through the scraps left from the anemone’s meals and occasional dead anemone tentacles, and functions as a safe nest site. In return, the anemonefish defends the anemone from its predators and parasites.^[4][5] The anemone also picks up nutrients from the anemonefish’s excrement.^[6] The nitrogen excreted from anemonefish increases the number of algae incorporated into the tissue of their hosts, which aids the anemone in tissue growth and regeneration.^[3] The activity of the anemonefish results in greater water circulation around the sea anemone,^[7] and it has been suggested that their bright coloring might lure small fish to the anemone, which then catches them.^[8] Studies on anemonefish have found that they alter the flow of water around sea anemone tentacles by certain behaviors and movements such as “wedging” and “switching”. Aeration of the host anemone tentacles allows for benefits to the metabolism of both partners, mainly by increasing anemone body size and both anemonefish and anemone respiration.^[9]

Bleaching of the host anemone can occur when warm temperatures cause a reduction in algal symbionts within the anemone. Bleaching of the host can cause a short-term increase in the metabolic rate of resident anemonefish, probably as a result of acute stress.^[10] Over time, however, there appears to be a down-regulation of metabolism and a reduced growth rate for fish associated with bleached anemones. These effects may stem from reduced food availability (e.g. anemone waste products, symbiotic algae) for the anemonefish.^[11]

Several theories are given about how they can survive the sea anemone venom:

• The mucus coating of the fish may be based on sugars rather than proteins. This would mean that anemones fail to recognize the fish as a potential food source and do not fire their nematocysts, or sting organelles.
• The coevolution of certain species of anemonefish with specific anemone host species may have allowed the fish to evolve an immunity to the nematocysts and toxins of their hosts. Amphiprion percula may develop resistance to the toxin from Heteractis magnifica, but it is not totally protected since it was shown experimentally to die when its skin, devoid of mucus, was exposed to the nematocysts of its host.^[12]

Anemonefish are the best known example of fish that are able to live among the venomous sea anemone tentacles, but several others occur, including juvenile threespot dascyllus, certain cardinalfish (such as Banggai cardinalfish), incognito (or anemone) goby, and juvenile painted greenling.^[13][14][15]

Reproduction

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In a group of anemonefish, a strict dominance hierarchy exists. The largest and most aggressive female is found at the top. Only two anemonefish, a male and a female, in a group reproduce – through external fertilization. Anemonefish are protandrous sequential hermaphrodites, meaning they develop into males first, and when they mature, they become females. If the female anemonefish is removed from the group, such as by death, one of the largest and most dominant males becomes a female.^[16] The remaining males move up a rank in the hierarchy. Clownfish live in a hierarchy, like hyenas, except smaller and based on size not sex, and order of joining/birth.^{[citation needed]}

Anemonefish lay eggs on any flat surface close to their host anemones. In the wild, anemonefish spawn around the time of the full moon. Depending on the species, they can lay hundreds or thousands of eggs. The male parent guards the eggs until they hatch about 6–10 days later, typically two hours after dusk.^[17]

Parental investment

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Anemonefish colonies usually consist of the reproductive male and female and a few male juveniles, which help tend the colony.^[18] Although multiple males cohabit an environment with a single female, polygamy does not occur and only the adult pair exhibits reproductive behavior. However, if the female dies, the social hierarchy shifts with the breeding male exhibiting protandrous sex reversal to become the breeding female. The largest juvenile then becomes the new breeding male after a period of rapid growth.^[19] The existence of protandry in anemonefish may rest on the case that nonbreeders modulate their phenotype in a way that causes breeders to tolerate them. This strategy prevents conflict by reducing competition between males for one female. For example, by purposefully modifying their growth rate to remain small and submissive, the juveniles in a colony present no threat to the fitness of the adult male, thereby protecting themselves from being evicted by the dominant fish.^[20]Duration: 38 seconds.0:38Video of a cinnamon clownfish swimming around an anemone

The reproductive cycle of anemonefish is often correlated with the lunar cycle. Rates of spawning for anemonefish peak around the first and third quarters of the moon. The timing of this spawn means that the eggs hatch around the full moon or new moon periods. One explanation for this lunar clock is that spring tides produce the highest tides during full or new moons. Nocturnal hatching during high tide may reduce predation by allowing for a greater capacity for escape. Namely, the stronger currents and greater water volume during high tide protect the hatchlings by effectively sweeping them to safety. Before spawning, anemonefish exhibit increased rates of anemone and substrate biting, which help prepare and clean the nest for the spawn.^[19]

Before making the clutch, the parents often clear an oval-shaped clutch varying in diameter for the spawn. Fecundity, or reproductive rate, of the females, usually ranges from 600 to 1,500 eggs depending on her size. In contrast to most animal species, the female only occasionally takes responsibility for the eggs, with males expending most of the time and effort. Male anemonefish care for their eggs by fanning and guarding them for 6 to 10 days until they hatch. In general, eggs develop more rapidly in a clutch when males fan properly, and fanning represents a crucial mechanism for successfully developing eggs. This suggests that males can control the success of hatching an egg clutch by investing different amounts of time and energy toward the eggs. For example, a male could choose to fan less in times of scarcity or fan more in times of abundance. Furthermore, males display increased alertness when guarding more valuable broods, or eggs in which paternity is guaranteed. Females, though, display generally less preference for parental behavior than males. All these suggest that males have increased parental investment towards eggs compared to females.^[21]

Clownfish hatchlings undergo development after hatching in regards to both their body size and fins. If maintained at the demanded thermal regulation, clownfish undergo proper development of their fins. Clownfish follow the ensuing order in their fin development “Pectorals < caudal < dorsal = anal < pelvic”. The early larval stage is crucial to ensure a healthy progression of growth.^[22]

Taxonomy

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Historically, anemonefish have been identified by morphological features and color pattern in the field, while in a laboratory, other features such as scalation of the head, tooth shape, and body proportions are used.^[2] These features have been used to group species into six complexes: percula, tomato, skunk, clarkii, saddleback, and maroon.^[23] As can be seen from the gallery, each of the fish in these complexes has a similar appearance. Genetic analysis has shown that these complexes are not monophyletic groups, particularly the 11 species in the A. clarkii group, where only A. clarkii and A. tricintus are in the same clade, with six species,A . allardi A. bicinctus, A. chagosensis, A. chrosgaster, A. fuscocaudatus, A. latifasciatus, and A. omanensis being in an Indian clade, A. chrysopterus having monospecific lineage, and A. akindynos in the Australian clade with A. mccullochi.^[24] Other significant differences are that A. latezonatus also has monospecific lineage, and A. nigripes is in the Indian clade rather than with A. akallopisos, the skunk anemonefish.^[25] A. latezonatus is more closely related to A. percula and Premnas biaculeatus than to the saddleback fish with which it was previously grouped.^[26][25]

Obligate mutualism was thought to be the key innovation that allowed anemonefish to radiate rapidly, with rapid and convergent morphological changes correlated with the ecological niches offered by the host anemones.^[26] The complexity of mitochondrial DNA structure shown by genetic analysis of the Australian clade suggested evolutionary connectivity among samples of A. akindynos and A. mccullochi that the authors theorize was the result of historical hybridization and introgression in the evolutionary past. The two evolutionary groups had individuals of both species detected, thus the species lacked reciprocal monophyly. No shared haplotypes were found between species.^[27]

Species

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Scientific name	Common name	Clade[24]	Complex	Image
Genus Amphiprion:[28]
A. akallopisos	Skunk anemonefish	A. akallopisos	Skunk
A. akindynos	Barrier Reef anemonefish	Australian	A. clarkii
A. allardi	Allard’s anemonefish	Indian	A. clarkii
A. barberi	Barber’s anemonefish	A. ephippium	A. ephippium
A. bicinctus	Two-band anemonefish	Indian	A. clarkii
A. chagosensis	Chagos anemonefish	Indian	A. clarkii
A. chrysogaster	Mauritian anemonefish	Indian	A. clarkii
A. chrysopterus	Orange-fin anemonefish	Monospecific lineage	A. clarkii
A. clarkii	Clark’s anemonefish	A. clarkii	A. clarkii
A. ephippium	Red saddleback anemonefish	A. ephippium	A. ephippium
A. frenatus	Tomato anemonefish	A. ephippium	A. ephippium
A. fuscocaudatus	Seychelles anemonefish	Indian[n 1]	A. clarkii
A. latezonatus	Wide-band anemonefish	Monospecific lineage	Saddleback
A. latifasciatus	Madagascar anemonefish	Indian	A. clarkii
A. leucokranos	White-bonnet anemonefish	Likely hybrid	Skunk
A. mccullochi	Whitesnout anemonefish	Australian	A. ephippium
A. melanopus	Red and black anemonefish	A. ephippium	A. ephippium
A. nigripes	Maldive anemonefish	Indian	Skunk
A. ocellaris	Ocellaris anemonefish	A. percula	Clownfish
A. omanensis	Oman anemonefish	Indian	A. clarkii
A. pacificus	Pacific anemonefish	A. akallopisos	Skunk
A. percula	Percula anemonefish	A. percula	Clownfish
A. perideraion	Pink skunk anemonefish	A. akallopisos	Skunk
A. polymnus	Saddleback anemonefish	A. polymnus	Saddleback
A. rubrocinctus	Australian anemonefish	A. ephippium	A. ephippium
A. sandaracinos	Orange anemonefish	A. akallopisos	Skunk
A. sebae	Sebae anemonefish	A. polymnus	Saddleback
A. thiellei	Thielle’s anemonefish	Likely hybrid	Skunk
A. tricinctus	Three-band anemonefish	A. clarkii	A. clarkii
Genus Premnas:[29]
P. biaculeatus	Maroon anemonefish	Percula	Maroon

Morphological diversity by complex

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• A. percula (clown anemonefish) in a ‘normal’ orange and a melanistic blackish variant
• A. clarkii (Clark’s anemonefish)
• A. polymnus (saddleback clownfish) off Sulawesi, Indonesia
• A. ephippium (red saddleback anemonefish)
• A. perideraion (pink skunk anemonefish)
• Male P. biaculeatus (maroon anemonefish) in Papua New Guinea

In the aquarium

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Anemonefish make up approximately 43% of the global marine ornamental trade, and approximately 25% of the global trade comes from fish bred in captivity, while the majority is captured from the wild,^[30][31] accounting for decreased densities in exploited areas.^[32] Public aquaria and captive-breeding programs are essential to sustain their trade as marine ornamentals, and has recently become economically feasible.^[33][34] It is one of a handful of marine ornamentals whose complete lifecycle has been in closed captivity. Members of some anemonefish species, such as the maroon clownfish, become aggressive in captivity; others, like the false percula clownfish, can be kept successfully with other individuals of the same species.^[35]

When a sea anemone is not available in an aquarium, the anemonefish may settle in some varieties of soft corals, or large polyp stony corals.^[36] Once an anemone or coral has been adopted, the anemonefish will defend it. Anemonefish, however, are not obligately tied to hosts, and can survive alone in captivity.^[37][38]

Clownfish sold from captivity make up a very small account (10%) of the total trade of these fishes. Designer Clownfish, scientifically named A. ocellaris are much costlier and obtaining them has disrupted their coral reefs. Their attractive allure, color, and patterning have made them out to be an attractive target in wild trading.^[22]

In popular culture

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In Disney Pixar‘s 2003 film Finding Nemo and its 2016 sequel Finding Dory main characters Nemo, his father Marlin, and his mother Coral are clownfish from the species A. ocellaris.^[39] The popularity of anemonefish for aquaria increased following the film’s release; it is the first film associated with an increase in the numbers of those captured in the wild

The term antelope refers to numerous extant or recently extinct species of the ruminant artiodactyl family Bovidae that are indigenous to most of Africa, India, the Middle East, Central Asia, and a small area of Eastern Europe. Antelopes do not form a monophyletic group, as some antelopes are more closely related to other bovid groups, such as bovines, goats, and sheep, than to other antelopes.

A stricter grouping, known as the true antelopes, includes only the genera Gazella, Nanger, Eudorcas, and Antilope.^[1] One North American mammal, the pronghorn or “pronghorn antelope”, is colloquially referred to as the “American antelope”, despite the fact that it belongs to a completely different family (Antilocapridae) than the true Old-World antelopes; pronghorn are the sole extant member of an extinct prehistoric lineage that once included many unique species.

Although antelope are sometimes referred to, and easily misidentified as, “deer” (cervids), true deer are only distant relatives of antelopes. While antelope are found in abundance in Africa, only one deer species is found on the continent—the Barbary red deer of Northern Africa. By comparison, numerous deer species are usually found in regions of the world with fewer or no antelope species present, such as throughout Southeast Asia, Europe and all of the Americas. This is likely due to competition over shared resources, as deer and antelope fill a virtually identical ecological niche in their respective habitats. Countries like India, however, have large populations of endemic deer and antelope, with the different species generally keeping to their own “niches” with minimal overlap.

Unlike deer, in which the males sport elaborate head antlers that are shed and regrown annually, antelope horns are bone and grow steadily, never falling off. If a horn is broken, it will either remain broken or take years to partially regenerate, depending on the species of the antelope.^[2]

Etymology

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The English word “antelope” first appeared in 1417 and is derived from the Old French antelop, itself derived from Medieval Latin ant(h)alopus, which in turn comes from the Byzantine Greek word ἀνθόλοψ, anthólops, first attested in Eustathius of Antioch (c. 336), according to whom it was a fabulous animal “haunting the banks of the Euphrates, very savage, hard to catch and having long, saw-like horns capable of cutting down trees”.^[3] It perhaps derives from Greek ἀνθος, anthos (flower) and ώψ, ops (eye), perhaps meaning “beautiful eye” or alluding to the animals’ long eyelashes. This, however, may be a folk etymology in Greek based on some earlier root. The word talopus and calopus, from Latin, came to be used in heraldry. In 1607, it was first used for living, cervine animals .

Species

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See also: List of even-toed ungulates by population

There are 91 antelope species, most of which are native to Africa, occur in about 30 genera. The classification of tribes or subfamilies within Bovoidea is still a matter of debate, with several alternative systems proposed.

Antelope are not a cladistic or taxonomically defined group.^[4] The term is used to describe all members of the family Bovidae that do not fall under the category of sheep, cattle, or goats. Usually, all species of the Antilopinae, Hippotraginae, Reduncinae, Cephalophinae, many Bovinae, the grey rhebok, and the impala are called antelope.

Distribution and habitat

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More species of antelope are native to Africa than to any other continent, almost exclusively in savannahs, with 25-40 species co-occurring over much of East Africa.^[5] Because savannah habitat in Africa has expanded and contracted five times over the last three million years, and the fossil record indicates this is when most extant species evolved, it is believed that isolation in refugia during contractions was a major driver of this diversification.^[6] Other species occur in Asia: the Arabian Peninsula is home to the Arabian oryx and Dorcas gazelle. South Asia is home to the nilgai, chinkara, blackbuck, Tibetan antelope, and four-horned antelope, while Russia and Central Asia have the Tibetan antelope and saiga.

No antelope species is native to Australasia or Antarctica, nor do any extant species occur in the Americas, though the nominate saiga subspecies occurred in North America during the Pleistocene. North America is currently home to the native pronghorn, which taxonomists do not consider a member of the antelope group, but which is often locally referred to as such (e.g., “American antelope”). In Europe, several extinct species occur in the fossil record, and the saiga was found widely during the Pleistocene but did not persist into the later Holocene,^[7] except in Russian Kalmykia and Astrakhan Oblast.^[8]

Many species of antelope have been imported to other parts of the world, especially the United States, for exotic game hunting. With some species possessing spectacular leaping and evasive skills, individuals may escape. Texas in particular has many game ranches, as well as habitats and climates that are very hospitable to African and Asian plains antelope species. Accordingly, wild populations of blackbuck antelope, gemsbok, and nilgai may be found in Texas.^[9]

Antelope live in a wide range of habitats. Most live in the African savannahs. However, many species are more secluded, such as the forest antelope, as well as the extreme cold-living saiga, the desert-adapted Arabian oryx, the rocky koppie-living klipspringer, and semiaquatic sitatunga.^[10]

Species living in forests, woodland, or bush tend to be sedentary, but many of the plains species undertake long migrations. These enable grass-eating species to follow the rains and thereby their food supply. The gnus and gazelles of East Africa perform some of the most impressive mass migratory circuits of all mammals.^[11]

Morphology

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Body and covering

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Antelope vary greatly in size. For example, a male common eland can measure 178 cm (5 ft 10 in) at the shoulder and weigh almost 950 kg (2,100 lb), whereas an adult royal antelope may stand only 24 cm (9+¹⁄₂ in) at the shoulder and weigh a mere 1.5 kg (3+¹⁄₄ lb).

Not surprisingly for animals with long, slender yet powerful legs, many antelope have long strides and can run fast. Some (e.g. klipspringer) are also adapted to inhabiting rock koppies and crags. Both dibatags and gerenuks habitually stand on their two hind legs to reach acacia and other tree foliage. Different antelope have different body types, which can affect movement. Duikers are short, bush-dwelling antelope that can pick through dense foliage and dive into the shadows rapidly. Gazelle and springbok are known for their speed and leaping abilities. Even larger antelope, such as nilgai, elands, and kudus, are capable of jumping 2.4 m (7 ft 10 in) or greater, although their running speed is restricted by their greater mass.

Antelope have a wide variety of coverings, though most have a dense coat of short fur. In most species, the coat (pelage) is some variation of a brown colour (or several shades of brown), often with white or pale underbodies. Exceptions include the zebra-marked zebra duiker, the grey, black, and white Jentink’s duiker, and the black lechwe. Most of the “spiral-horned” antelope have pale, vertical stripes on their backs. Many desert and semidesert species are particularly pale, some almost silvery or whitish (e.g. Arabian oryx); the beisa and southern oryxes have gray and black pelages with vivid black-and-white faces. Common features of various gazelles are white rumps, which flash a warning to others when they run from danger, and dark stripes midbody (the latter feature is also shared by the springbok and beira). The springbok also has a pouch of white, brushlike hairs running along its back, which opens up when the animal senses danger, causing the dorsal hairs to stand on end.

Many antelope are sexually dimorphic. In most species, both sexes have horns, but those of males tend to be larger. Males tend to be larger than the females, but exceptions in which the females tend to be heavier than the males include the bush duiker, dwarf antelope, Cape grysbok, and oribi, all rather small species. A number of species have hornless females (e.g., sitatunga, red lechwe, and suni). In some species, the males and females have differently coloured pelages (e.g. blackbuck and nyala).

Many wild antelopes are characterized by high running and jumping abilities. Their main defence againts predators is to try to escape.

Species such as black wildebeest, springbok, blesbok, mountain reedbuck, greater kudu as well the European fallow deer have a high concentrations of glycolitic fast twitch type IIx muscle fibers; smaller species naturally have a higher concentrations of type IIx fibers than larger species.^[12][13][14] Although their concentration of type IIx fibers is still lower than that of the wild cheetah, other running-adapted mammal; wild cheetah vastus lateralis muscle have a concentration of 76 % of type IIx fibers, compared to 58 % of springbok, 57 % of mountain reedbuck, 55 % of blesbok, 48 % of European fallow deer, 43 % of greater kudu and 30 % black wildebeest.^[15]

The activity of the anaerobic enzyme LDH, an indicator of a principally anaerobic muscle metabolism, is around 4 times more higher than that of humans, a level of activity comparable to that of the lion, but lower than that of the wild caracal and especially that of the wild cheetah; LDH activity is 6 times higher than that of the humans in caracal and 9 times higher in the wild cheetah.^[16][15]

Activity of aerobic enzymes CS and 3HAD is higher than that of the felids in general and is comparable to that of human endurance runners. This indicates muscles capable of both high speed and high endurance.^[12][14]

In the impala, hindlimbs muscles form 17.5 % of their body mass while forelimbs muscles form 11.3 %.^[17] Furthermore, antelopes tend to have long limb bones for their body masses.^[18]

A maximum running speed of 63.7 km/h for the impala and 54 km/h for the blue wildebeest has been estimated by GPS-IMU collars.^[17][19] A top speed of 65.2 km/h is obtained by calculating the distance and time it takes a Thomson’s gazelle to escape from a aproaching human.^[20] Film analysis of lion hunts gives a maximum speed of 90 km/h for the Thomson’s gazelle.^[21] By speedometer reading when an animal runs alongside a car on a straight course, a maximum speed of up to 70 km/h has been estimated for the eland and the topi, and up to 80 km/h for the hartebeest, blue wildebeest, Grant’s gazelle and Thomson’s gazelle.^[22]

Sensory and digestive systems

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Antelope are ruminants, so they have well-developed molar teeth, which grind cud (food balls stored in the stomach) into a pulp for further digestion. They have no upper incisors, but rather a hard upper gum pad, against which their lower incisors bite to tear grass stems and leaves.

Like many other herbivores, antelope rely on keen senses to avoid predators. Their eyes are placed on the sides of their heads, giving them a broad radius of vision with minimal binocular vision. Their horizontally elongated pupils also help in this respect. Acute senses of smell and hearing give antelope the ability to perceive danger at night out in the open (when predators are often on the prowl). These same senses play an important role in contact between individuals of the same species; markings on their heads, ears, legs, and rumps are used in such communication. Many species “flash” such markings, as well as their tails; vocal communications include loud barks, whistles, “moos”, and trumpeting; many species also use scent marking to define their territories or simply to maintain contact with their relatives and neighbors.

Antelope horns

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“Antelope horns” redirects here. For the milkweed commonly known as antelope horns, see Asclepias asperula.

The size and shape of antelope horns varies greatly. Those of the duikers and dwarf antelope tend to be simple “spikes”, but differ in the angle to the head from backward curved and backward pointing (e.g. yellow-backed duiker) to straight and upright (e.g. steenbok). Other groups have twisted (e.g. common eland), spiral (e.g. greater kudu), “recurved” (e.g. the reedbucks), lyrate (e.g. impala), or long, curved (e.g. the oryxes) horns. Horns are not shed and their bony cores are covered with a thick, persistent sheath of horny material, both of which distinguish them from antlers.^[23]

Antelope horns are efficient weapons, and tend to be better developed in those species where males fight over females (large herd antelope) than in solitary or lekking species. With male-male competition for mates, horns are clashed in combat. Males more commonly use their horns against each other than against another species. The boss of the horns is typically arranged in such a way that two antelope striking at each other’s horns cannot crack each other’s skulls, making a fight via horn more ritualized than dangerous. Many species have ridges in their horns for at least two-thirds the length of their horns, but these ridges are not a direct indicator of age.

Behavior

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Mating strategies

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Antelope are often classified by their reproductive behavior.

Small antelope, such as dik-diks, tend to be monogamous. They live in a forest environment with patchy resources, and a male is unable to monopolize more than one female due to this sparse distribution. Larger forest species often form very small herds of two to four females and one male.

Some species, such as lechwes, pursue a lek breeding system, where the males gather on a lekking ground and compete for a small territory, while the females appraise males and choose one with which to mate.

Large grazing antelope, such as impala or wildebeest, form large herds made up of many females and a single breeding male, which excludes all other males, often by combat.

Defense

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Antelope pursue a number of defense strategies, often dictated by their morphology.

Large antelope that gather in large herds, such as wildebeest, rely on numbers and running speed for protection. In some species, adults will encircle the offspring, protecting them from predators when threatened. Many forest antelope rely on cryptic coloring and good hearing to avoid predators. Forest antelope often have very large ears and dark or striped colorations. Small antelope, especially duikers, evade predation by jumping into dense bush where the predator cannot pursue.^[24] Springboks use a behavior known as stotting to confuse predators.

Open grassland species have nowhere to hide from predators, so they tend to be fast runners. They are agile and have good endurance—these are advantages when pursued by sprint-dependent predators such as cheetahs, which are the fastest of land animals, but tire quickly. Reaction distances vary with predator species and behaviour. For example, gazelles may not flee from a lion until it is closer than 200 m (650 ft)—lions hunt as a pride or by surprise, usually by stalking; one that can be seen clearly is unlikely to attack. However, sprint-dependent cheetahs will cause gazelles to flee at a range of over 800 metres (¹⁄₂ mile).^[25]

If escape is not an option, antelope are capable of fighting back. Oryxes in particular have been known to stand sideways like many unrelated bovids to appear larger than they are, and may charge at a predator as a last resort.^[26]

Status

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About 25 species are rated by the IUCN as endangered,^[27] such as the dama gazelle and mountain nyala. A number of subspecies are also endangered, including the giant sable antelope and the mhorr gazelle. The main causes for concern for these species are habitat loss, competition with cattle for grazing, and trophy hunting.

The chiru or Tibetan antelope is hunted for its pelt, which is used in making shahtoosh wool, used in shawls. Since the fur can only be removed from dead animals, and each animal yields very little of the downy fur, several antelope must be killed to make a single shawl. This unsustainable demand has led to enormous declines in the chiru population.^[28][29]

The saiga is hunted for its horns, which are considered an aphrodisiac by some cultures. Only the males have horns, and have been so heavily hunted that some herds contain up to 800 females to one male. The species showed a steep decline and was formerly classified as critically endangered.^[30] However, the saigas have experienced a massive regrowth^[31] and are now classified as near threatened.^[32]

Lifespan

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It is difficult to determine how long antelope live in the wild. With the preference of predators towards old and infirm individuals, which can no longer sustain peak speeds, few wild prey-animals live as long as their biological potential. In captivity, wildebeest have lived beyond 20 years old, and impalas have reached their late teens.^[33]

Relationship with humans

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Culture

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The antelope’s horn is prized for supposed medicinal and magical powers in many places. The horn of the male saiga, in Eastern practice, is ground as an aphrodisiac, for which it has been hunted nearly to extinction.^[34] In the Congo, it is thought to confine spirits. The antelope’s ability to run swiftly has also led to their association with the wind, such as in the Rig Veda, as the steeds of the Maruts and the wind god Vayu. There is, however, no scientific evidence that the horns of any antelope have any change on a human’s physiology or characteristics.

In Mali, antelope were believed to have brought the skills of agriculture to mankind.^[35]

Humans have also used the term “Antelope” to refer to a tradition usually found in the sport of track and field.

Domestication

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Domestication of animals requires certain traits in the animal that antelope do not typically display. Most species are difficult to contain in any density, due to the territoriality of the males, or in the case of oryxes (which have a relatively hierarchical social structure), an aggressive disposition; they can easily kill a human. Because many have extremely good jumping abilities, providing adequate fencing is a challenge. Also, antelope will consistently display a fear response to perceived predators, such as humans, making them very difficult to herd or handle. Although antelope have diets and rapid growth rates highly suitable for domestication, this tendency to panic and their non-hierarchical social structure explains why farm-raised antelope are uncommon. Ancient Egyptians kept herds of gazelles and addax for meat, and occasionally pets. It is unknown whether they were truly domesticated, but it seems unlikely, as no domesticated gazelles exist today.

However, humans have had success taming certain species, such as the elands. These antelope sometimes jump over each other’s backs when alarmed, but this incongruous talent seems to be exploited only by wild members of the species; tame elands do not take advantage of it and can be enclosed within a very low fence. Their meat, milk, and hides are all of excellent quality, and experimental eland husbandry has been going on for some years in both Ukraine and Zimbabwe. In both locations, the animal has proved wholly amenable to domestication.^[36] Similarly, European visitors to Arabia reported “tame gazelles are very common in the Asiatic countries of which the species is a native; and the poetry of these countries abounds in allusions both to the beauty and the gentleness of the gazelle.”^[37] Other antelope that have been tamed successfully include the gemsbok,^[38] the kudu,^[39] and the springbok.^[39]

Hybrid antelope

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A wide variety of antelope hybrids have been recorded in zoos, game parks, and wildlife ranches, due to either a lack of more appropriate mates in enclosures shared with other species or a misidentification of species. The ease of hybridization shows how closely related some antelope species are. With few exceptions, most hybrid antelope occur only in captivity.

Most hybrids occur between species within the same genus. All reported examples occur within the same subfamily. As with most mammal hybrids, the less closely related the parents, the more likely the offspring will be sterile.^[33]

Heraldry

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Antelope are a common symbol in heraldry, though they occur in a highly distorted form from nature. The heraldic antelope has the body of a stag and the tail of a lion, with serrated horns, and a small tusk at the end of its snout. This bizarre and inaccurate form was invented by European heralds in the Middle Ages, who knew little of foreign animals and made up the rest. The antelope was mistakenly imagined to be a monstrous beast of prey; the 16th century poet Edmund Spenser referred to it as being “as fierce and fell as a wolf.”^[40]

Antelope can all also occur in their natural form, in which case they are termed “natural antelope” to distinguish them from the more usual heraldic antelope.^[41] The arms previously used by the Republic of South Africa featured a natural antelope, along with an oryx.