Jaguar

The jaguar (Panthera onca) is a large cat species and the only living member of the genus Panthera that is native to the Americas. Its distinctively marked coat features pale yellow to tan colored fur covered by spots that transition to rosettes on the sides, although a melanistic black coat appears in some individuals. With a body length of up to 1.85 m (6 ft 1 in) and a weight of up to 158 kg (348 lb), it is the biggest cat species in the Americas and the third largest in the world. The jaguar's powerful bite allows it to pierce the carapaces of turtles and tortoises, and to employ an unusual killing method: it bites directly through the skull of mammalian prey between the ears to deliver a fatal blow to the brain.

The modern jaguar's ancestors probably entered the Americas from Eurasia during the Early Pleistocene via the land bridge that once spanned the Bering Strait. The oldest jaguar fossils found in North America date to between 0.85 to 0.82 million years ago. Today, the jaguar's range extends from the Southwestern United States across Mexico and much of Central America, the Amazon rainforest and south to Paraguay and northern Argentina. It inhabits a variety of forested and open terrains, but its preferred habitat is tropical and subtropical moist broadleaf forest, wetlands and wooded regions. It is adept at swimming and is largely a solitary, opportunistic, stalk-and-ambush apex predator. As a keystone species, it plays an important role in stabilizing ecosystems and in regulating prey populations.

The jaguar is threatened by habitat loss, habitat fragmentation, poaching for trade with its body parts and killings in human–wildlife conflict situations, particularly with ranchers in Central and South America. It has been listed as Near Threatened on the IUCN Red List since 2002. The wild population is thought to have declined since the late 1990s. Priority areas for jaguar conservation comprise 51 large areas inhabited by at least 50 breeding individuals, called Jaguar Conservation Units. They are located in 36 geographic regions from Mexico to Argentina.

The jaguar has featured prominently in the mythology of indigenous peoples of the Americas, including those of the Aztec and Maya civilizations.

Etymology

The word "jaguar" is possibly derived from the Tupi-Guarani word yaguara meaning 'wild beast that overcomes its prey at a bound'. Because jaguar also applies to other animals, indigenous peoples in Guyana call it jaguareté, with the added sufix eté, meaning "true beast". "Onca" is derived from the Portuguese name onça for a spotted cat that is larger than a lynx; cf. ounce. The word "panther" is derived from classical Latin panthēra, itself from the ancient Greek πάνθηρ (pánthēr).

In North America, the word is pronounced with two syllables, as , while in British English, it is pronounced with three, as .

Taxonomy and evolution

Taxonomy

In 1758, Carl Linnaeus described the jaguar in his work Systema Naturae and gave it the scientific name Felis onca.

In the 19th and 20th centuries, several jaguar type specimens formed the basis for descriptions of subspecies. In 1939, Reginald Innes Pocock recognized eight subspecies based on the geographic origins and skull morphology of these specimens. Pocock did not have access to sufficient zoological specimens to critically evaluate their subspecific status but expressed doubt about the status of several. Later consideration of his work suggested only three subspecies should be recognized. The description of P. o. palustris was based on a fossil skull.

By 2005, nine subspecies were considered to be valid taxa:

• P. o. onca (Linnaeus, 1758) was a jaguar from Brazil.
• P. o. peruviana (De Blainville, 1843) was a jaguar skull from Peru.
• P. o. hernandesii (Gray, 1857) was a jaguar from Mazatlán in Mexico.
• P. o. palustris (Ameghino, 1888) was a fossil jaguar mandible excavated in the Sierras Pampeanas of Córdova District, Argentina.
• P. o. centralis (Mearns, 1901) was a skull of a male jaguar from Talamanca, Costa Rica.
• P. o. goldmani (Mearns, 1901) was a jaguar skin from Yohatlan in Campeche, Mexico.
• P. o. paraguensis (Hollister, 1914) was a skull of a male jaguar from Paraguay.
• P. o. arizonensis (Goldman, 1932) was a skin and skull of a male jaguar from the vicinity of Cibecue, Arizona.
• P. o. veraecrucis (Nelson and Goldman, 1933) was a skull of a male jaguar from San Andrés Tuxtla in Mexico.

Reginald Innes Pocock placed the jaguar in the genus Panthera and observed that it shares several morphological features with the leopard (P. pardus). He, therefore, concluded that they are most closely related to each other. Results of morphological and genetic research indicate a clinal north–south variation between populations, but no evidence for subspecific differentiation. DNA analysis of 84 jaguar samples from South America revealed that the gene flow between jaguar populations in Colombia was high in the past. Since 2017, the jaguar is considered to be a monotypic taxon, though the modern Panthera onca onca is still distinguished from two fossil subspecies, Panthera onca augusta and Panthera onca mesembrina. However, the 2024 study suggested that the validity of subspecific assignments on both P. o. augusta and P. o. mesembrina remains unresolved, since both fossil and living jaguars show a considerable variation in morphometry.

Evolution

The Panthera lineage is estimated to have genetically diverged from the common ancestor of the Felidae around 9.32 to 4.47 million years ago to 11.75 to 0.97 million years ago. Some genetic analyses place the jaguar as a sister species to the lion with which it diverged 3.46 to 1.22 million years ago, but other studies place the lion closer to the leopard.

The lineage of the jaguar appears to have originated in Africa and spread to Eurasia 1.95–1.77 mya. The living jaguar species is often suggested to have descended from the Eurasian Panthera gombaszogensis. The ancestor of the jaguar entered the American continent via Beringia, the land bridge that once spanned the Bering Strait, Some authors have disputed the close relationship between P. gombaszogensis (which is primarily known from Eurasia) and the modern jaguar. The oldest fossils of modern jaguars (P. onca) have been found in North America dating between 850,000-820,000 years ago. Results of mitochondrial DNA analysis of 37 jaguars indicate that current populations evolved between 510,000 and 280,000 years ago in northern South America and subsequently recolonized North and Central America after the extinction of jaguars there during the Late Pleistocene.

Two extinct subspecies of jaguar are recognized in the fossil record: the North American P. o. augusta and South American P. o. mesembrina.

Description

The jaguar is a compact and muscular animal. It is the largest cat native to the Americas and the third largest in the world, exceeded in size only by the tiger and the lion. It stands 57 to 81 cm (22.4 to 31.9 in) tall at the shoulders. Its size and weight vary considerably depending on sex and region: weights in most regions are normally in the range of 56–96 kg (123–212 lb). Exceptionally big males have been recorded to weigh as much as 158 kg (348 lb). The smallest females from Middle America weigh about 36 kg (79 lb). It is sexually dimorphic, with females typically being 10–20% smaller than males. The length from the nose to the base of the tail varies from 1.12 to 1.85 m (3.7 to 6.1 ft). The tail is 45 to 75 cm (17.7 to 29.5 in) long and the shortest of any big cat. Its muscular legs are shorter than the legs of other Panthera species with similar body weight.

Size tends to increase from north to south. Jaguars in the Chamela-Cuixmala Biosphere Reserve on the Pacific coast of central Mexico weighed around 50 kg (110 lb). Jaguars in Venezuela and Brazil are much larger, with average weights of about 95 kg (209 lb) in males and of about 56–78 kg (123–172 lb) in females.