Lion[1] Temporal range: Early Pleistocene to recent
Male
Female (lioness)
Conservation status
Vulnerable (IUCN 3.1)[2]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Felidae
Genus:	Panthera
Species:	P. leo
Binomial name
Panthera leo (Linnaeus, 1758)[3]
Distribution of lions in India. The Gir Forest, in the State of Gujarat, is the last natural range of approximately 300 wild Asiatic lions. There are plans to reintroduce some lions to Kuno Wildlife Sanctuary in the neighbouring State of Madhya Pradesh.
Synonyms
Felis leo Linnaeus, 1758[3]

The lion (Panthera leo) is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg (550 lb) in weight,^[4] it is the second-largest living cat after the tiger. Wild lions currently exist in Sub-Saharan Africa and in Asia with an endangered remnant population in Gir Forest National Park in India, having disappeared from North Africa and Southwest Asia in historic times. Until the late Pleistocene, about 10,000 years ago, the lion was the most widespread large land mammal after humans. They were found in most of Africa, across Eurasia from western Europe to India, and in the Americas from the Yukon to Peru.^[5] The lion is a vulnerable species, having seen a possibly irreversible population decline^{[clarification needed]} of thirty to fifty percent over the past two decades in its African range.^[2] Lion populations are untenable outside designated reserves and national parks. Although the cause of the decline is not fully understood, habitat loss and conflicts with humans are currently the greatest causes of concern. Within Africa, the West African lion population is particularly endangered.

Lions live for ten to fourteen years in the wild, while in captivity they can live longer than twenty years. In the wild, males seldom live longer than ten years, as injuries sustained from continual fighting with rival males greatly reduce their longevity.^[6] They typically inhabit savanna and grassland, although they may take to bush and forest. Lions are unusually social compared to other cats. A pride of lions consists of related females and offspring and a small number of adult males. Groups of female lions typically hunt together, preying mostly on large ungulates. Lions are apex and keystone predators, although they scavenge as opportunity allows. While lions do not typically hunt humans, some have been known to do so. Sleeping mainly during the day, lions are primarily nocturnal, although bordering on crepuscular^[7][8] in nature.

Highly distinctive, the male lion is easily recognised by its mane, and its face is one of the most widely recognised animal symbols in human culture. Depictions have existed from the Upper Paleolithic period, with carvings and paintings from the Lascaux and Chauvet Caves, through virtually all ancient and medieval cultures where they once occurred. It has been extensively depicted in sculptures, in paintings, on national flags, and in contemporary films and literature. Lions have been kept in menageries since the time of the Roman Empire and have been a key species sought for exhibition in zoos over the world since the late eighteenth century. Zoos are cooperating worldwide in breeding programs for the endangered Asiatic subspecies.

Etymology[link]

The lion's name, similar in many Romance languages, is derived from the Latin leo;^[9] and the Ancient Greek λέων (leon).^[10] The Hebrew word לָבִיא (lavi) may also be related.^[11] It was one of the many species originally described by Linnaeus, who gave it the name Felis leo, in his eighteenth century work, Systema Naturae.^[3]

Taxonomy and evolution[link]

The lion is a species of the genus Panthera and its closest relatives are the other species of this genus: the tiger, the jaguar, and the leopard. Panthera leo itself evolved in Africa between 1 million and 800,000 years ago, before spreading throughout the Holarctic region.^[12] It appeared in the fossil record in Europe for the first time 700,000 years ago with the subspecies Panthera leo fossilis at Isernia in Italy. From this lion derived the later cave lion (Panthera leo spelaea), which appeared about 300,000 years ago.^[13] Lions died out in northern Eurasia at the end of the last glaciation, about 10,000 years ago;^[14] this may have been secondary to the extinction of Pleistocene megafauna.^[15]

Subspecies[link]

Traditionally, twelve recent subspecies of lion were recognised, distinguished by mane appearance, size, and distribution. Because these characteristics are very insignificant and show a high individual variability, most of these forms were probably not true subspecies, especially as they were often based upon zoo material of unknown origin that may have had "striking, but abnormal" morphological characteristics.^[16] Today only eight subspecies are usually accepted,^[14][17] although one of these, the Cape lion, formerly described as Panthera leo melanochaita, probably is invalid.^[17] Even the remaining seven subspecies might be too many. While the status of the Asiatic lion (P. l. persica) as a subspecies is generally accepted, the systematic relationships among African lions are still not completely resolved. Mitochondrial variation in living African lions seemed to be modest according to some younger studies and therefore all sub-Saharan lions sometimes have been considered a single subspecies. However, a recent study revealed, that lions from western and central Africa differ genetically from lions of southern or eastern Africa. According to this study, Western African lions are more closely related to Asian lions, than to South or East African lions. These findings might be explained by a late Pleistocene extinction event of lions in western and central Africa and a subsequent recolonisation of these parts from Asia.^[18] Previous studies, which were focusing mainly on lions from eastern and southern parts of Africa already showed that these can be possibly divided in two main clades: one to the west of the Great Rift Valley and the other to the east. Lions from Tsavo in Eastern Kenya are much closer genetically to lions in Transvaal (South Africa), than to those in the Aberdare Range in Western Kenya.^[19] Another study, revealed, that there are three major types of lions, one North African–Asian, one southern African and one middle African.^[20] Conversely, Per Christiansen found that using skull morphology allowed him to identify the subspecies krugeri, nubica, persica, and senegalensis, while there was overlap between bleyenberghi with senegalensis and krugeri. The Asiatic lion persica was the most distinctive, and the Cape lion had characteristics allying it more with persica than the other subsaharan lions. He had analysed 58 lion skulls in three European museums.^[21]

Recent[link]

Eight recent (Holocene) subspecies are recognised today:

• P. l. persica, known as the Asiatic lion or South Asian, Persian, or Indian Lion, once was widespread from Turkey, across Southwest Asia, to Pakistan, India, and even to Bangladesh. However, large prides and daylight activity made them easier to poach than tigers or leopards; now around 300 exist in and near the Gir Forest of India.^[22] Genetic evidence suggests its ancestors split from the ancestors of subsaharan African lions between 74 and 203 thousand years ago.^[14]
• P. l. leo, known as the Barbary lion, originally ranged from Morocco to Egypt. It is extinct in the wild due to excessive hunting, as the last wild Barbary lion was killed in Morocco in 1922.^[23] This was one of the largest of the lion subspecies,^[24] with reported lengths of 3–3.3 metres (10–10.8 ft) and weights of more than 200 kilograms (440 lb) for males. It appears to be more closely related to the Asiatic rather than subsaharan lions. There are a number of animals in captivity likely to be Barbary lions,^[25] particularly 90 animals descended from the Moroccan Royal collection at Rabat Zoo.^[26]
• P. l. senegalensis, known as the West African Lion, is found in western Africa, from Senegal to the Central African Republic.^[27][28]
• P. l. azandica, known as the Northeast Congo Lion, is found in the northeastern parts of the Congo.^[27]
• P. l. nubica, known as the East African, Massai Lion is found in east Africa, from Ethiopia and Kenya to Tanzania and Mozambique.,^[28] a local population is known as Tsavo Lion.
• P. l. bleyenberghi, known as the Southwest African or Katanga Lion, is found in southwestern Africa, Namibia, Botswana, Angola, Katanga (Democratic Republic of the Congo), Zambia, and Zimbabwe.^[28]
• P. l. krugeri, known as the Southeast African Lion or Transvaal Lion, is found in the Transvaal region of southeastern Africa, including Kruger National Park.^[28]
• P. l. melanochaita, known as the Cape lion, became extinct in the wild around 1860. Results of mitochondrial DNA research do not support the status as a distinct subspecies. It seems probable that the Cape lion was only the southernmost population of the extant P. l. krugeri.^[17]

Pleistocene[link]

Several additional subspecies of lion existed in prehistoric times:

• P. l. fossilis, known as the Early Middle Pleistocene European cave lion, flourished about 500,000 years ago; fossils have been recovered from Germany and Italy. It was larger than today's African lions, reaching the American cave lion in size^[14][29]
  

  

  cave lions, Chamber of Felines, Lascaux caves
• P. l. spelaea, known as the European cave lion, Eurasian cave lion, or Upper Pleistocene European cave lion, occurred in Eurasia 300,000 to 10,000 years ago.^[14] This species is known from Paleolithic cave paintings (such as the one displayed to the right), ivory carvings, and clay busts,^[30] indicating it had protruding ears, tufted tails, perhaps faint tiger-like stripes, and that at least some males had a ruff or primitive mane around their necks.^[31]
• P. l. atrox, known as the American lion or American cave lion, was abundant in the Americas from Canada to Peru in the Pleistocene Epoch until about 10,000 years ago. This form is the sister clade of P. l. spelaea, and likely arose when an early P. l. spelaea population became isolated south of the North American continental ice sheet about 340 000 years ago.^[32] One of the largest purported lion subspecies to have existed, its body length is estimated to have been 1.6–2.5 m (5–8 ft).^[33]

Dubious[link]

• P. l. youngi or Panthera youngi, flourished 350,000 years ago.^[5] Its relationship to the extant lion subspecies is obscure, and it probably represents a distinct species.
• P. l. sinhaleyus, known as the Sri Lanka Lion, appears to have become extinct around 39,000 years ago. It is only known from two teeth found in deposits at Kuruwita. Based on these teeth, P. Deraniyagala erected this subspecies in 1939.^[34]
• P. l. vereshchagini, the Beringian cave lion of Yakutia (Russia), Alaska (USA), and the Yukon Territory (Canada), has been considered a subspecies separate from P. l. spelaea on morphological grounds. However, mitochondrial DNA sequences obtained from cave lion fossils from Europe and Alaska were indistinguishable.^[32]
• P. l. europaea, known as the European Lion, was probably identical with Panthera leo persica or Panthera leo spelea; its status as a subspecies is unconfirmed. It became extinct around 100 AD due to persecution and over-exploitation. It inhabited the Balkans, the Italian Peninsula, southern France, and the Iberian Peninsula. It was a very popular object of hunting among Romans and Greeks.
• P. l. maculatus, known as the marozi or spotted lion, sometimes is believed to be a distinct subspecies, but may be an adult lion that has retained its juvenile spotted pattern. If it was a subspecies in its own right, rather than a small number of aberrantly coloured individuals, it has been extinct since 1931. A less likely identity is a natural leopard-lion hybrid commonly known as a leopon.^[35]

Hybrids[link]

Video of lion cubs in the wild, South Africa

Lions have been known to breed with tigers (most often the Siberian and Bengal subspecies) to create hybrids called ligers and tiglons (or tigons).^[36] They also have been crossed with leopards to produce leopons,^[37] and jaguars to produce jaglions. The marozi is reputedly a spotted lion or a naturally occurring leopon, while the Congolese Spotted Lion is a complex lion-jaguar-leopard hybrid called a lijagulep. Such hybrids were once commonly bred in zoos, but this is now discouraged due to the emphasis on conserving species and subspecies. Hybrids are still bred in private menageries and in zoos in China.

The liger is a cross between a male lion and a tigress.^[38] Because the growth-inhibiting gene from the female tiger is absent, a growth-promoting gene is passed on by the male lion, the resulting ligers grow far larger than either parent. They share physical and behavioural qualities of both parent species (spots and stripes on a sandy background). Male ligers are sterile, but female ligers are often fertile. Males have about a 50 percent chance of having a mane, but if they grow one, their manes will be modest: around 50 percent of a pure lion mane. Ligers are typically between 3.0 and 3.7 m (10 to 12 feet) in length, and can be between 360 and 450 kg (800 to 1,000 pounds) or more.^[38] The less common tiglon or tigon is a cross between a lioness and a male tiger.^[39] In contrast to ligers, tigons are often relatively small in comparison to their parents, because of reciprocal gene effects.^[40]

Characteristics[link]

A skeletal mount of an African Lion attacking a Common Eland on display at The Museum of Osteology, Oklahoma City, Oklahoma

The lion is the tallest (at the shoulder) of all living cats, averaging about 14 cm (5.5 in) taller than the tiger. Behind only the tiger, the lion is the second largest living felid in length and weight. Its skull is very similar to that of the tiger, although the frontal region is usually more depressed and flattened, with a slightly shorter postorbital region. The lion's skull has broader nasal openings than the tiger. However, due to the amount of skull variation in the two species, usually, only the structure of the lower jaw can be used as a reliable indicator of species.^[41] Lion coloration varies from light buff to yellowish, reddish, or dark ochraceous brown. The underparts are generally lighter and the tail tuft is black. Lion cubs are born with brown rosettes (spots) on their body, rather like those of a leopard. Although these fade as lions reach adulthood, faint spots often may still be seen on the legs and underparts, particularly on lionesses.

Lions are the only members of the cat family to display obvious sexual dimorphism—that is, males and females look distinctly different. They also have specialised roles that each gender plays in the pride. For instance, the lioness, the hunter, lacks the male's thick mane. The colour of the male's mane varies from blond to black, generally becoming darker as the lion grows older.

During confrontations with others, the mane makes the lion look larger.

Weights for adult lions range between 150–250 kg (330–550 lb) for males and 120–182 kg (264–400 lb) for females.^[4] Nowell and Jackson report average weights of 181 kg (400 lb) for males and 126 kg (280 lb) for females.^[23] Lions tend to vary in size depending on their environment and area, resulting in a wide spread in recorded weights. For instance, lions in southern Africa tend to be about 5 percent heavier than those in East Africa, in general.^[42]

Head and body length is 170–250 cm (5 ft 7 in – 8 ft 2 in) in males and 140–175 cm (4 ft 7 in – 5 ft 9 in) in females; shoulder height is up to 123 cm (4 ft) in males and as low as 91 cm (3 ft) in females.^[43] The tail length is 90–105 cm (2 ft 11 in - 3 ft 5 in) in males and 70–100 cm in females (2 ft 4 in – 3 ft 3 in).^[4] The longest known lion, at nearly 3.6 m (12 ft) in total length, was a black-maned male shot near Mucsso, southern Angola in October 1973; the heaviest lion known in the wild was a man-eater shot in 1936 just outside Hectorspruit in eastern Transvaal, South Africa and weighed 313 kg (690 lb).^[44] Another notably outsized male lion, which was shot near Mount Kenya, weighed in at 272 kg (600 lb).^[23] Lions in captivity tend to be larger than lions in the wild—the heaviest lion on record is a male at Colchester Zoo in England named Simba in 1970, which weighed 375 kg (826 lb).^[45] However, the frequently cited maximum head and body length of 250 cm (8 ft 2 in) fits rather to extinct Pleistocene forms, like the American lion, with even large modern lions measuring several centimeters less in length^[46]

The most distinctive characteristic shared by both females and males is that the tail ends in a hairy tuft. In some lions, the tuft conceals a hard "spine" or "spur", approximately 5 mm long, formed of the final sections of tail bone fused together. The lion is the only felid to have a tufted tail—the function of the tuft and spine are unknown. Absent at birth, the tuft develops around 5½ months of age and is readily identifiable at 7 months.^[47]

Mane[link]

The mane of the adult male lion, unique among cats, is one of the most distinctive characteristics of the species. It makes the lion appear larger, providing an excellent intimidation display; this aids the lion during confrontations with other lions and with the species' chief competitor in Africa, the spotted hyena.^[48] The presence, absence, colour, and size of the mane is associated with genetic precondition, sexual maturity, climate, and testosterone production; the rule of thumb is the darker and fuller the mane, the healthier the lion. Sexual selection of mates by lionesses favors males with the densest, darkest mane.^[49] Research in Tanzania also suggests mane length signals fighting success in male–male relationships. Darker-maned individuals may have longer reproductive lives and higher offspring survival, although they suffer in the hottest months of the year.^[50] In prides including a coalition of two or three males, it is possible that lionesses solicit mating more actively with the males who are more heavily maned.^[49]

A maneless male lion, who also has little body hair—from Tsavo East National Park, Kenya

Scientists once believed that the distinct status of some subspecies could be justified by morphology, including the size of the mane. Morphology was used to identify subspecies such as the Barbary lion and Cape lion. Research has suggested, however, that environmental factors influence the colour and size of a lion's mane, such as the ambient temperature.^[50] The cooler ambient temperature in European and North American zoos, for example, may result in a heavier mane. Thus the mane is not an appropriate marker for identifying subspecies.^[17][51] The males of the Asiatic subspecies, however, are characterised by sparser manes than average African lions.^[52]

In the Pendjari National Park area almost all males are maneless or have very weak manes.^[53] Maneless male lions have also been reported from Senegal and from Tsavo East National Park in Kenya, and the original male white lion from Timbavati also was maneless. The testosterone hormone has been linked to mane growth, therefore castrated lions often have minimal to no mane, as the removal of the gonads inhibits testosterone production.^[54]

Cave paintings of extinct European cave lions exclusively show animals with no mane, or just the hint of a mane, suggesting that they were maneless.^[31]

White lions[link]

White lions owe their colouring to a recessive gene; they are rare forms of the subspecies Panthera leo krugeri

The white lion is not a distinct subspecies, but a special morph with a genetic condition, leucism,^[16] that causes paler colouration akin to that of the white tiger; the condition is similar to melanism, which causes black panthers. They are not albinos, having normal pigmentation in the eyes and skin. White Transvaal lion (Panthera leo krugeri) individuals occasionally have been encountered in and around Kruger National Park and the adjacent Timbavati Private Game Reserve in eastern South Africa, but are more commonly found in captivity, where breeders deliberately select them. The unusual cream colour of their coats is due to a recessive gene.^[55] Reportedly, they have been bred in camps in South Africa for use as trophies to be killed during canned hunts.^[56]
Kevin Richardson is an animal behaviourist who works with the native big cats of Africa. He currently works in a special facility called the Kingdom of the White Lion in Broederstroom^[57] which is 50 miles form Johannesburg.^[58] The site was built with the help of Rodney Fuhr^[59] and was made for the movie set of White Lion: Home is a Journey.^[58] He has 39 white lions on-site^[57] and works diligently to protect and preserve the white lion type. While the park is currently a private property, there are plans to open it to the public soon.^[60]

Behaviour[link]

Lions spend much of their time resting and are inactive for about 20 hours per day.^[61] Although lions can be active at any time, their activity generally peaks after dusk with a period of socializing, grooming, and defecating. Intermittent bursts of activity follow through the night hours until dawn, when hunting most often takes place. They spend an average of two hours a day walking and 50 minutes eating.^[62]

Group organization[link]

Lions are the most socially inclined of all wild felids, most of which remain quite solitary in nature. The lion is a predatory carnivore who manifest two types of social organization. Some are residents, living in groups, called prides.^[63] The pride usually consists of five or six related females, their cubs of both sexes, and one or two males (known as a coalition if more than one) who mate with the adult females (although extremely large prides, consisting of up to 30 individuals, have been observed). The number of adult males in a coalition is usually two, but may increase to four and decrease again over time. Male cubs are excluded from their maternal pride when they reach maturity.

Two lionesses and a mature male of a pride, northern Serengeti

The second organizational behaviour is labeled nomads, who range widely and move about sporadically, either singularly or in pairs.^[63] Pairs are more frequent among related males who have been excluded from their birth pride. Note that a lion may switch lifestyles; nomads may become residents and vice versa. Males have to go through this lifestyle and some never are able to join another pride. A female who becomes a nomad has much greater difficulty joining a new pride, as the females in a pride are related, and they reject most attempts by an unrelated female to join their family group.

The area a pride occupies is called a pride area, whereas that by a nomad is a range.^[63] The males associated with a pride tend to stay on the fringes, patrolling their territory. Why sociality—the most pronounced in any cat species—has developed in lionesses is the subject of much debate. Increased hunting success appears an obvious reason, but this is less than sure upon examination: coordinated hunting does allow for more successful predation, but also ensures that non-hunting members reduce per capita caloric intake, however, some take a role raising cubs, who may be left alone for extended periods of time. Members of the pride regularly tend to play the same role in hunts. The health of the hunters is the primary need for the survival of the pride and they are the first to consume the prey at the site it is taken. Other benefits include possible kin selection (better to share food with a related lion than with a stranger), protection of the young, maintenance of territory, and individual insurance against injury and hunger.^[23]

Video of a lion in the wild

Lionesses do the majority of the hunting for their pride, being smaller, swifter and more agile than the males, and unencumbered by the heavy and conspicuous mane, which causes overheating during exertion. They act as a co-ordinated group in order to stalk and bring down the prey successfully. However, if nearby the hunt, males have a tendency to dominate the kill once the lionesses have succeeded. They are more likely to share with the cubs than with the lionesses, but rarely share food they have killed by themselves. Smaller prey is eaten at the location of the hunt, thereby being shared among the hunters; when the kill is larger it often is dragged to the pride area. There is more sharing of larger kills,^[64] although pride members often behave aggressively toward each other as each tries to consume as much food as possible.

Both males and females defend the pride against intruders. Some individual lions consistently lead the defence against intruders, while others lag behind.^[65] Lions tend to assume specific roles in the pride. Those lagging behind may provide other valuable services to the group.^[66] An alternative hypothesis is that there is some reward associated with being a leader who fends off intruders and the rank of lionesses in the pride is reflected in these responses.^[67] The male or males associated with the pride must defend their relationship to the pride from outside males who attempt to take over their relationship with the pride. Females form the stable social unit in a pride and do not tolerate outside females;^[68] membership only changes with the births and deaths of lionesses,^[69] although some females do leave and become nomadic.^[70] Subadult males on the other hand, must leave the pride when they reach maturity at around 2–3 years of age.^[70]

Hunting and diet[link]

While a lioness such as this one has very sharp teeth, prey is usually killed by strangulation

Lions are powerful animals that usually hunt in coordinated groups and stalk their chosen prey. However, they are not particularly known for their stamina—for instance, a lioness' heart makes up only 0.57 percent of her body weight (a male's is about 0.45 percent of his body weight), whereas a hyena's heart is close to 1 percent of its body weight.^[71] Thus, they only run fast in short bursts,^[72] and need to be close to their prey before starting the attack. They take advantage of factors that reduce visibility; many kills take place near some form of cover or at night.^[73] They sneak up to the victim until they reach a distance of around 30 metres (98 ft) or less. The lioness is the one who does the hunting for the pride, since the lioness is more aggressive by nature. The male lion usually stays and watches its young while waiting for the lionesses to return from the hunt. Typically, several lionesses work together and encircle the herd from different points. Once they have closed with a herd, they usually target the closest prey. The attack is short and powerful; they attempt to catch the victim with a fast rush and final leap. The prey usually is killed by strangulation,^[74] which can cause cerebral ischemia or asphyxia (which results in hypoxemic, or "general", hypoxia). The prey also may be killed by the lion enclosing the animal's mouth and nostrils in its jaws^[75] (which would also result in asphyxia). Smaller prey, though, may simply be killed by a swipe of a lion's paw.^[4]

Lioness in a burst of speed while hunting in the Serengeti

The prey consists mainly of large mammals, with a preference for wildebeest, impalas, zebras, buffalo, and warthogs in Africa and nilgai, wild boar, and several deer species in India. Many other species are hunted, based on availability. Mainly this will include ungulates weighing between 50 and 300 kg (110–660 lb) such as kudu, hartebeest, gemsbok, and eland.^[4] Occasionally, they take relatively small species such as Thomson's gazelle or springbok. Lions hunting in groups are capable of taking down most animals, even healthy adults, but in most parts of their range they rarely attack very large prey such as fully grown male giraffes due to the danger of injury.

Extensive statistics collected over various studies show that lions normally feed on mammals in the range 190–550 kg (420–1210 lb). In Africa, wildebeest rank at the top of preferred prey (making nearly half of the lion prey in the Serengeti) followed by zebra.^[76] Most adult hippopotamuses, rhinoceroses, elephants, and smaller gazelles, impala, and other agile antelopes are generally excluded. However giraffes and buffalos are often taken in certain regions. For instance, in Kruger National Park, giraffes are regularly hunted.^[77] In Manyara Park, Cape buffaloes constitute as much as 62% of the lion's diet,^[78] due to the high number density of buffaloes. Occasionally hippopotamus is also taken, but adult rhinoceroses are generally avoided. Even though smaller than 190 kg (420 lb), warthogs are often taken depending on availability.^[79] In some areas, lions specialise in hunting atypical prey species; this is the case at the Savuti river, where they prey on elephants.^[80] Park guides in the area reported that the lions, driven by extreme hunger, started taking down baby elephants, and then moved on to adolescents and, occasionally, fully grown adults during the night when elephants' vision is poor.^[81] Lions also attack domestic livestock; in India cattle contribute significantly to their diet.^[52] Lions are capable of killing other predators such as leopards, cheetahs, hyenas, and wild dogs, though (unlike most felids) they seldom devour the competitors after killing them. They also scavenge animals either dead from natural causes (disease) or killed by other predators, and keep a constant lookout for circling vultures, being keenly aware that they indicate an animal dead or in distress.^[82] A lion may gorge itself and eat up to 30 kg (66 lb) in one sitting;^[83] if it is unable to consume all the kill it will rest for a few hours before consuming more. On a hot day, the pride may retreat to shade leaving a male or two to stand guard.^[84] An adult lioness requires an average of about 5 kg (11 lb) of meat per day, a male about 7 kg (15.5 lb).^[85]

Four lions take down a cape buffalo in the central Serengeti, Tanzania

Because lionesses hunt in open spaces where they are easily seen by their prey, cooperative hunting increases the likelihood of a successful hunt; this is especially true with larger species. Teamwork also enables them to defend their kills more easily against other large predators such as hyenas, which may be attracted by vultures from kilometres away in open savannas. Lionesses do most of the hunting; males attached to prides do not usually participate in hunting, except in the case of larger quarry such as giraffe and buffalo. In typical hunts, each lioness has a favored position in the group, either stalking prey on the "wing" then attacking, or moving a smaller distance in the centre of the group and capturing prey in flight from other lionesses.^[86] Young lions first display stalking behaviour around three months of age, although they do not participate in hunting until they are almost a year old. They begin to hunt effectively when nearing the age of two.^[87]

Predator competition[link]

Subadult male lion and spotted hyena in the Masai Mara

Lions and spotted hyenas occupy the same ecological niche (and hence compete) where they coexist. A review of data across several studies indicates a dietary overlap of 58.6%.^[88] Lions typically ignore spotted hyenas, unless they are on a kill or are being harassed by them, while the latter tend to visibly react to the presence of lions, whether there is food or not. Lions seize the kills of spotted hyenas: in the Ngorongoro crater, it is common for lions to subsist largely on kills stolen from hyenas, causing the hyenas to increase their kill rate. Lions are quick to follow the calls of hyenas feeding, a fact which was proven by Dr. Hans Kruuk, who found that lions repeatedly approached him whenever he played the tape-recorded calls of hyenas feeding.^[89] When confronted on a kill by lions, spotted hyenas will either leave or wait patiently at a distance of 30–100 m (100–350 ft) until the lions have finished.^[90] In some cases, spotted hyenas are bold enough to feed alongside lions, and may occasionally force the lions off a kill. The two species may act aggressively toward one another even when there is no food involved. Lions may charge at hyenas and maul them for no apparent reason: one male lion was filmed killing two matriarch hyenas on separate occasions without eating them,^[91] and lion predation can account for up to 71% of hyena deaths in Etosha. Spotted hyenas have adapted by frequently mobbing lions which enter their territories.^[92] Experiments on captive spotted hyenas revealed that specimens with no prior experience with lions act indifferently to the sight of them, but will react fearfully to the scent.^[89]

Lions tend to dominate smaller felines such as cheetahs and leopards where they co-occur, stealing their kills and killing their cubs and even adults when given the chance. The cheetah has a 50% chance of losing its kill to lions or other predators.^[93] Lions are major killers of cheetah cubs, up to 90% of which are lost in their first weeks of life due to attacks by other predators. Cheetahs avoid competition by hunting at different times of the day and hide their cubs in thick brush. Leopards also use such tactics, but have the advantage of being able to subsist much better on small prey than either lions or cheetahs. Also, unlike cheetahs, leopards can climb trees and use them to keep their cubs and kills away from lions. However, lionesses will occasionally be successful in climbing to retrieve leopard kills.^[94] Similarly, lions dominate African wild dogs, not only taking their kills but also preying on young and (rarely) adult dogs. Population densities of wild dogs are low in areas where lions are more abundant.^[95] However, in Kruger National Park, there have been records of wild dogs killing lions and there is one report of eight dogs killing and eating an adult male.^[96]

The Nile crocodile is the only sympatric predator (besides humans) that can singly threaten the lion. Depending on the size of the crocodile and the lion, either can lose kills or carrion to the other. Lions have been known to kill crocodiles venturing onto land,^[97] while the reverse is true for lions entering waterways, as evidenced by the occasional lion claw found in crocodile stomachs.^[98]

Reproduction and life cycle[link]

Most lionesses will have reproduced by the time they are four years of age.^[99] Lions do not mate at any specific time of year, and the females are polyestrous.^[100] As with other cats, the male lion's penis has spines which point backwards. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which may cause ovulation.^[101] A lioness may mate with more than one male when she is in heat;^[102] during a mating bout, which could last several days, the couple copulates twenty to forty times a day and are likely to forgo eating. Lions reproduce very well in captivity.

Lions mating in Ngorongoro Conservation Area, Tanzania

The average gestation period is around 110 days,^[100] the female giving birth to a litter of one to four cubs in a secluded den (which may be a thicket, a reed-bed, a cave or some other sheltered area) usually away from the rest of the pride. She will often hunt by herself while the cubs are still helpless, staying relatively close to the thicket or den where the cubs are kept.^[103] The cubs themselves are born blind—their eyes do not open until roughly a week after birth. They weigh 1.2–2.1 kg (2.6–4.6 lb) at birth and are almost helpless, beginning to crawl a day or two after birth and walking around three weeks of age.^[104] The lioness moves her cubs to a new den site several times a month, carrying them one by one by the nape of the neck, to prevent scent from building up at a single den site and thus avoiding the attention of predators that may harm the cubs.^[103]

Usually, the mother does not integrate herself and her cubs back into the pride until the cubs are six to eight weeks old.^[105] However, sometimes this introduction to pride life occurs earlier, particularly if other lionesses have given birth at about the same time. For instance, lionesses in a pride often synchronise their reproductive cycles so that they cooperate in the raising and suckling of the young (once the cubs are past the initial stage of isolation with their mother), who suckle indiscriminately from any or all of the nursing females in the pride. In addition to greater protection, the synchronization of births also has an advantage in that the cubs end up being roughly the same size, and thus have an equal chance of survival. If one lioness gives birth to a litter of cubs a couple of months after another lioness, for instance, then the younger cubs, being much smaller than their older brethren, are usually dominated by larger cubs at mealtimes—consequently, death by starvation is more common amongst the younger cubs.

A pregnant lioness (right)

In addition to starvation, cubs also face many other dangers, such as predation by jackals, hyenas, leopards, martial eagles and snakes. Even buffaloes, should they catch the scent of lion cubs, often stampede towards the thicket or den where they are being kept, doing their best to trample the cubs to death while warding off the lioness. Furthermore, when one or more new males oust the previous male(s) associated with a pride, the conqueror(s) often kill any existing young cubs,^[106] perhaps because females do not become fertile and receptive until their cubs mature or die. All in all, as many as 80 percent of the cubs will die before the age of two.^[107]

When first introduced to the rest of the pride, the cubs initially lack confidence when confronted with adult lions other than their mother. However, they soon begin to immerse themselves in the pride life, playing amongst themselves or attempting to initiate play with the adults. Lionesses with cubs of their own are more likely to be tolerant of another lioness's cubs than lionesses without cubs. The tolerance of the male lions towards the cubs varies—sometimes, a male will patiently let the cubs play with his tail or his mane, whereas another may snarl and bat the cubs away.^[108]

The tolerance of male lions towards the cubs varies. They are, however, generally more likely to share food with the cubs than with the lionesses.

Weaning occurs after six to seven months. Male lions reach maturity at about 3 years of age and, at 4–5 years of age, are capable of challenging and displacing the adult male(s) associated with another pride. They begin to age and weaken between 10 and 15 years of age at the latest,^[109] if they have not already been critically injured while defending the pride (once ousted from a pride by rival males, male lions rarely manage a second take-over). This leaves a short window for their own offspring to be born and mature. If they are able to procreate as soon as they take over a pride, potentially, they may have more offspring reaching maturity before they also are displaced. A lioness often will attempt to defend her cubs fiercely from a usurping male, but such actions are rarely successful. He usually kills all of the existing cubs who are less than two years old. A lioness is weaker and much lighter than a male; success is more likely when a group of three or four mothers within a pride join forces against one male.^[106]

Contrary to popular belief, it is not only males that are ousted from their pride to become nomads, although most females certainly do remain with their birth pride. However, when the pride becomes too large, the next generation of female cubs may be forced to leave to eke out their own territory. Furthermore, when a new male lion takes over the pride, subadult lions, both male and female, may be evicted.^[110] Life is harsh for a female nomad. Nomadic lionesses rarely manage to raise their cubs to maturity, without the protection of other pride members. One scientific study reports that both males and females may interact homosexually.^[111][112]

Health[link]

Although adult lions have no natural predators, evidence suggests that the majority die violently from humans or other lions.^[113] Lions often inflict serious injuries on each other, either members of different prides encountering each other in territorial disputes, or members of the same pride fighting at a kill.^[114] Crippled lions and lion cubs may fall victim to hyenas, leopards, or be trampled by buffalo or elephants, and careless lions may be maimed when hunting prey.^[115]

One of the tree climbing Lions of the Serengeti, Tanzania

Various species of tick commonly infest the ears, neck and groin regions of most lions.^[116][117] Adult forms of several species of the tapeworm genus Taenia have been isolated from intestines, the lions having ingested larval forms from antelope meat.^[118] Lions in the Ngorongoro Crater were afflicted by an outbreak of stable fly (Stomoxys calcitrans) in 1962; this resulted in lions becoming covered in bloody bare patches and emaciated. Lions sought unsuccessfully to evade the biting flies by climbing trees or crawling into hyena burrows; many perished or emigrated as the population dropped from 70 to 15 individuals.^[119] A more recent outbreak in 2001 killed six lions.^[120] Lions, especially in captivity, are vulnerable to the canine distemper virus (CDV), feline immunodeficiency virus (FIV), and feline infectious peritonitis (FIP).^[16] CDV is spread through domestic dogs and other carnivores; a 1994 outbreak in Serengeti National Park resulted in many lions developing neurological symptoms such as seizures. During the outbreak, several lions died from pneumonia and encephalitis.^[121] FIV, which is similar to HIV while not known to adversely affect lions, is worrisome enough in its effect in domestic cats that the Species Survival Plan recommends systematic testing in captive lions. It occurs with high to endemic frequency in several wild lion populations, but is mostly absent from Asiatic and Namibian lions.^[16]

Communication[link]

Head rubbing and licking are common social behaviours within a pride

When resting, lion socialization occurs through a number of behaviours, and the animal's expressive movements are highly developed. The most common peaceful tactile gestures are head rubbing and social licking,^[122] which have been compared with grooming in primates.^[123] Head rubbing—nuzzling one's forehead, face and neck against another lion—appears to be a form of greeting,^[124] as it is seen often after an animal has been apart from others, or after a fight or confrontation. Males tend to rub other males, while cubs and females rub females.^[125] Social licking often occurs in tandem with head rubbing; it is generally mutual and the recipient appears to express pleasure. The head and neck are the most common parts of the body licked, which may have arisen out of utility, as a lion cannot lick these areas individually.^[126]

Lions have an array of facial expressions and body postures that serve as visual gestures.^[127] Their repertoire of vocalizations is also large; variations in intensity and pitch, rather than discrete signals, appear central to communication. Lion sounds include snarling, purring, hissing, coughing, miaowing, woofing and roaring. Lions tend to roar in a very characteristic manner, starting with a few deep, long roars that trail off into a series of shorter ones. They most often roar at night; the sound, which can be heard from a distance of 8 kilometres (5.0 mi), is used to advertise the animal's presence.^[128] Lions have the loudest roar of any big cat.

Distribution and habitat[link]

Two male Asiatic lions in Sanjay Gandhi National Park, Mumbai, India. The wild population of the endangered Asiatic lions is restricted to the Gir Forest National Park in western India.^[129]

In Africa, lions can be found in savanna grasslands with scattered Acacia trees which serve as shade;^[130] their habitat in India is a mixture of dry savanna forest and very dry deciduous scrub forest.^[131] The habitat of lions originally spanned the southern parts of Eurasia, ranging from Greece to India, and most of Africa except the central rainforest-zone and the Sahara desert. Herodotus reported that lions had been common in Greece around 480 BC; they attacked the baggage camels of the Persian king Xerxes on his march through the country. Aristotle considered them rare by 300 BC. By 100 AD they were extirpated.^[132] A population of Asiatic lions survived until the tenth century in the Caucasus, their last European outpost.^[133]

The species was eradicated from Palestine by the Middle Ages and from most of the rest of Asia after the arrival of readily available firearms in the eighteenth century. Between the late nineteenth and early twentieth century they became extinct in North Africa and Southwest Asia. By the late nineteenth century the lion had disappeared from Turkey and most of northern India,^[16][134] while the last sighting of a live Asiatic lion in Iran was in 1941 (between Shiraz and Jahrom, Fars Province), although the corpse of a lioness was found on the banks of the Karun river, Khūzestān Province in 1944. There are no subsequent reliable reports from Iran.^[83] The subspecies now survives only in and around the Gir Forest of northwestern India.^[22] About 300 lions live in a 1,412 km² (545 sq mi) sanctuary in the state of Gujarat, which covers most of the forest. Their numbers are slowly increasing.^[135]

Population and conservation status[link]

The Asiatic lion, whose habitat once ranged from the Mediterranean to north-west Indian subcontinent, is today found only in the Gir Forest of Gujarat, India. Only about 320 Asiatic lions survive in the wild.^[136]

Most lions now live in eastern and southern Africa, and their numbers there are rapidly decreasing, with an estimated 30–50% decline over the last two decades.^[2] Estimates of the African lion population range between 16,500 and 47,000 living in the wild in 2002–2004,^[137][138] down from early 1990s estimates that ranged as high as 100,000 and perhaps 400,000 in 1950. Primary causes of the decline include disease and human interference.^[2] Habitat loss and conflicts with humans are considered the most significant threats to the species.^[139][140] The remaining populations are often geographically isolated from one another, which can lead to inbreeding, and consequently, reduced genetic diversity. Therefore the lion is considered a vulnerable species by the International Union for Conservation of Nature, while the Asiatic subspecies is endangered.^[141] The lion population in the region of West Africa is isolated from lion populations of Central Africa, with little or no exchange of breeding individuals. The number of mature individuals in West Africa is estimated by two separate recent surveys at 850–1,160 (2002/2004). There is disagreement over the size of the largest individual population in West Africa: the estimates range from 100 to 400 lions in Burkina Faso's Arly-Singou ecosystem.^[2] Another population in northwestern Africa is found in Waza National Park, where only about 14-21 animals persist^[142]

Conservation of both African and Asian lions has required the setup and maintenance of national parks and game reserves; among the best known are Etosha National Park in Namibia, Serengeti National Park in Tanzania, and Kruger National Park in eastern South Africa. Outside these areas, the issues arising from lions' interaction with livestock and people usually results in the elimination of the former.^[143] In India, the last refuge of the Asiatic lion is the 1,412 km² (545 sq mi) Gir Forest National Park in western India which had about 359 lions (as of April 2006). As in Africa, numerous human habitations are close by with the resultant problems between lions, livestock, locals and wildlife officials.^[144] The Asiatic Lion Reintroduction Project plans to establish a second independent population of Asiatic lions at the Kuno Wildlife Sanctuary in the Indian state of Madhya Pradesh.^[145] It is important to start a second population to serve as a gene pool for the last surviving Asiatic lions and to help develop and maintain genetic diversity enabling the species to survive.

The former popularity of the Barbary lion as a zoo animal has meant that scattered lions in captivity are likely to be descended from Barbary lion stock. This includes twelve lions at Port Lympne Wild Animal Park in Kent, England that are descended from animals owned by the King of Morocco.^[146] Another eleven animals believed to be Barbary lions were found in Addis Ababa zoo, descendants of animals owned by Emperor Haile Selassie. WildLink International, in collaboration with Oxford University, launched their ambitious International Barbary Lion Project with the aim of identifying and breeding Barbary lions in captivity for eventual reintroduction into a national park in the Atlas Mountains of Morocco.^[147]

Following the discovery of the decline of lion population in Africa, several coordinated efforts involving lion conservation have been organised in an attempt to stem this decline. Lions are one species included in the Species Survival Plan, a coordinated attempt by the Association of Zoos and Aquariums to increase its chances of survival. The plan was originally started in 1982 for the Asiatic lion, but was suspended when it was found that most Asiatic lions in North American zoos were not genetically pure, having been hybridised with African lions. The African lion plan started in 1993, focusing especially on the South African subspecies, although there are difficulties in assessing the genetic diversity of captive lions, since most individuals are of unknown origin, making maintenance of genetic diversity a problem.^[16]

Man-eaters[link]

While lions do not usually hunt people, some (usually males) seem to seek out human prey; well-publicised cases include the Tsavo maneaters, where 28 railway workers building the Kenya-Uganda Railway were taken by lions over nine months during the construction of a bridge over the Tsavo River in Kenya in 1898, and the 1991 Mfuwe man-eater, which killed six people in the Laungwa River Valley in Zambia.^[148] In both, the hunters who killed the lions wrote books detailing the animals' predatory behaviour. The Mfuwe and Tsavo incidents bear similarities: the lions in both incidents were larger than normal, lacked manes, and seemed to suffer from tooth decay. The infirmity theory, including tooth decay, is not favored by all researchers; an analysis of teeth and jaws of man-eating lions in museum collections suggests that, while tooth decay may explain some incidents, prey depletion in human-dominated areas is a more likely cause of lion predation on humans.^[149]

In their analysis of Tsavo and man-eating generally, Kerbis Peterhans and Gnoske acknowledge that sick or injured animals may be more prone to man-eating, but that the behaviour is "not unusual, nor necessarily 'aberrant'" where the opportunity exists; if inducements such as access to livestock or human corpses are present, lions will regularly prey upon human beings. The authors note that the relationship is well-attested amongst other pantherines and primates in the paleontological record.^[150]

The lion's proclivity for man-eating has been systematically examined. American and Tanzanian scientists report that man-eating behaviour in rural areas of Tanzania increased greatly from 1990 to 2005. At least 563 villagers were attacked and many eaten over this period—a number far exceeding the more famed "Tsavo" incidents of a century earlier. The incidents occurred near Selous National Park in Rufiji District and in Lindi Province near the Mozambican border. While the expansion of villagers into bush country is one concern, the authors argue that conservation policy must mitigate the danger because, in this case, conservation contributes directly to human deaths. Cases in Lindi have been documented where lions seize humans from the center of substantial villages.^[151] Another study of 1,000 people attacked by lions in southern Tanzania between 1988 and 2009 found that the weeks following the full moon (when there was less moonlight) were a strong indicator of increased night attacks on people.^[152]