Lion
The lion (Panthera leo) is a species in the family Felidae; it is a muscular, deep-chested cat with a short, rounded head, a reduced neck and round ears, and a hairy tuft at the end of its tail. It is sexually dimorphic; adult male lions have a prominent mane, which is the most recognisable feature of the species. With a typical head-to-body length of 184–208 cm (72–82 in) they are larger than females at 160–184 cm (63–72 in). It is a social species, forming groups called prides. A lion pride consists of a few adult males, related females and cubs. Groups of female lions usually hunt together, preying mostly on large ungulates. The lion is an apex and keystone predator, although some lions scavenge when opportunities occur, and have been known to hunt humans, although the species typically does not.
Typically, the lion inhabits grasslands and savannas but is absent in dense forests. It is usually more diurnal than other big cats, but when persecuted it adapts to being active at night and at twilight. In the Pleistocene, the lion ranged throughout Eurasia, Africa and North America but today it has been reduced to fragmented populations in Sub-Saharan Africa and one critically endangered population in western India. It has been listed as Vulnerable on the IUCN Red List since 1996 because populations in African countries have declined by about 43% since the early 1990s. Lion populations are untenable outside designated protected areas. Although the cause of the decline is not fully understood, habitat loss and conflicts with humans are the greatest causes for concern.
One of the most widely recognised animal symbols in human culture, the lion has been extensively depicted in sculptures and 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 zoological gardens across the world since the late 18th century. Cultural depictions of lions were prominent in the Upper Paleolithic period; carvings and paintings from the Lascaux and Chauvet Caves in France have been dated to 17,000 years ago, and depictions have occurred in virtually all ancient and medieval cultures that coincided with the lion's former and current ranges
Etymology
The word 'lion' is derived from Latin: leo[4] and Ancient Greek: λέων (leon).[5] The word lavi (Hebrew: לָבִיא) may also be related.[6] The generic name Panthera is traceable to the classical Latin word 'panthēra' and the ancient Greek word πάνθηρ 'panther'.[7] Panthera is phonetically similar to the Sanskrit word पाण्डर pând-ara meaning 'pale yellow, whitish, white'.[8]
Taxonomy
Felis leo was the scientific name used by Carl Linnaeus in 1758, who described the lion in his work Systema Naturae.[3] The genus name Panthera was coined by German naturalist Lorenz Oken in 1816.[13] Between the mid-18th and mid-20th centuries, 26 lion specimens were described and proposed as subspecies, of which 11 were recognised as valid in 2005.[1] They were distinguished on the basis of appearance, size and colour of mane. Because these characteristics show much variation between individuals, most of these forms were probably not true subspecies, especially because they were often based upon museum material with "striking, but abnormal" morphological characteristics.[14]
Subspecies
In the 19th and 20th centuries, several lion type specimens were described and proposed as subspecies, with about a dozen recognised as valid taxa until 2017.[1] Between 2008 and 2016, IUCN Red List assessors used only two subspecific names: P. l. leo for African lion populations and P. l. persica for the Asiatic lion population.[2][15][16] In 2017, the Cat Classification Task Force of the Cat Specialist Group revised lion taxonomy, and recognises two subspecies based on results of several phylogeographic studies on lion evolution, namely:[17]
P. l. leo (Linnaeus, 1758) − the nominate lion subspecies includes the Asiatic lion, the regionally extinct Barbary lion, and lion populations in West and northern parts of Central Africa.[17] Synonyms include P. l. persica (Meyer, 1826), P. l. senegalensis (Meyer, 1826), P. l. kamptzi (Matschie, 1900), and P. l. azandica (Allen, 1924).[1] Some authors referred to it as 'northern lion' and 'northern subspecies'.[18][19]
P. l. melanochaita (Smith, 1842) − includes the extinct Cape lion and lion populations in East and Southern African regions.[17] Synonyms include P. l. somaliensis (Noack 1891), P. l. massaica (Neumann, 1900), P. l. sabakiensis (Lönnberg, 1910), P. l. bleyenberghi (Lönnberg, 1914), P. l. roosevelti (Heller, 1914), P. l. nyanzae (Heller, 1914), P. l. hollisteri (Allen, 1924), P. l. krugeri (Roberts, 1929), P. l. vernayi (Roberts, 1948), and P. l. webbiensis (Zukowsky, 1964).[1][20] It has been referred to as 'southern subspecies' and 'southern lion'.[19]
Lion samples from some parts of the Ethiopian Highlands cluster genetically with those from Cameroon and Chad, while lions from other areas of Ethiopia cluster with samples from East Africa. Researchers therefore assume that Ethiopia is a contact zone between the two subspecies.[21]
Fossil records
Other lion subspecies or sister species to the modern lion existed in prehistoric times:[22]
P. l. sinhaleyus was a fossil carnassial excavated in Sri Lanka, which was attributed to a lion. It is thought to have become extinct around 39,000 years ago.[23]
P. leo fossilis, P. fossilis or P. spelaea fossilis was larger than the modern lion and lived in the Middle Pleistocene. Bone fragments were excavated in caves in the United Kingdom, Germany, Italy and Czech Republic.[24][25]
Panthera spelaea lived in Eurasia and Beringia during the Late Pleistocene. It became extinct due to climate warming latest by 11,900 years ago.[26] Bone fragments excavated in European, North Asian, Canadian and Alaskan caves indicate that it ranged from Europe across Siberia into western Alaska.[27] It likely derived from P. fossilis,[28] and was genetically isolated and highly distinct from the lion in Africa and Asia.[29][28] It is depicted in Paleolithic cave paintings, ivory carvings, and clay busts.[30]
P. l. atrox or P. atrox ranged in the Americas from Canada to possibly Patagonia.[31][31] The American lion arose when a cave lion population in Beringia became isolated south of the Cordilleran Ice Sheet about 370,000 years ago.[32][33] A fossil from Edmonton dates to 11,355 ± 55 years ago.[34]
Evolution
The lion's closest relatives are the other species of the genus Panthera, namely tiger, snow leopard, jaguar, and leopard. Results of phylogenetic studies published in 2006 and 2009 indicate that the jaguar and the lion belong to one sister group that diverged about 2.06 million years ago.[9][10] Results of later studies indicate that the leopard and the lion belong to the same sister group, which diverged 3.1–1.95 million years ago.[11][12] The geographic origin of the Panthera is most likely northern Central Asia. The leopard-lion clade was distributed in the Asian and African Palearctic since at least the Early Pliocene. The lion is thought to have diverged from the cave lion clade in Holarctic Asia or Africa in the Pliocene,[35] around 1.89 million years ago.[28] Hybridisation between ancestors of lion and snow leopard lineages may have continued until about 2.1 million years ago.[36] The Eurasian and American cave lions became extinct at the end of the last glacial period without mitochondrial descendants on other continents.[29][37][38]
The modern lion was probably widely distributed in Africa during the Middle Pleistocene and started to diverge in sub-Saharan Africa during the Late Pleistocene. Lion populations in East and Southern Africa became separated from populations in West and North Africa when the equatorial rainforest expanded 183,500–81,800 years ago. The expansion of the Sahara 83,100–26,600 years ago caused the separation of populations in West and North Africa. As the rainforest decreased, thus giving rise to more open habitats, lions moved from West to Central Africa. Lions from North Africa dispersed to southern Europe and Asia 38,800–8,300 ago.[39] Extinction of lions in southern Europe, North Africa and the Middle East interrupted gene flow between lion populations in Asia and Africa. Genetic evidence revealed numerous mutations in lion samples from East and Southern Africa, which indicates that this group has a longer evolutionary history than genetically less diverse lion samples from Asia and West and Central Africa.[40] Results of phylogeographic research indicate that the two living lion subspecies diverged about 245,000 years ago.[21]
Hybrids
In zoos, lions have been bred with tigers to create hybrids for the curiosity of visitors or for scientific purpose.[41][42] The liger is bigger than a lion and a tiger, whereas most tigons are relatively small compared to their parents because of reciprocal gene effects.[43][44] The leopon is a hybrid between a lion and leopard.[45]
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