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The etymology of the word jaguar is unclear. Some sources
suggest a borrowing from the South American Tupi language to
English via Portuguese, while others attribute the term to the
related Guaraní languages. In the Tupi language, the original
and complete indigenous name for the species is jaguara, which
has been reported as a denotation for any carnivorous animal—in
the compound form jaguareté, -eté means "true". In the related
Guaraní languages, yaguareté has been variously translated as
"the real fierce beast", "dog-bodied", or "fierce dog". Early
etymological reports were that jaguara means "a beast that kills
its prey with one bound," and this claim persists in a number of
sources. However, this has been challenged as incorrect. In many
Central and South American countries, the cat is referred to as
el tigre ("the tiger").
The first component of its scientific designation, Panthera onca,
is often presumed to derive from Greek pan- ("all") and ther
("beast"), but this may be a folk etymology. Although it came
into English through the classical languages, panthera is
probably of East Asian origin, meaning "the yellowish animal,"
or "whitish-yellow".
Onca is said to denote "barb" or "hook", a reference to the
animal's powerful claws, but the most correct etymology is
simply that it is an adaptation of the current Portuguese name
for the animal, onça (on-sa), with the cedilla dropped for
typographical reasons.
The jaguar, Panthera onca, is the only New World member of the
Panthera genus. DNA evidence shows that the lion, the tiger, the
leopard, the jaguar, the snow leopard and the clouded leopard
share a common ancestor and that this group is between six and
ten million years old; the fossil record points to the emergence
of Panthera just two to 3.8 million years ago. The clouded
leopard (Neofelis nebulosa) is generally placed at the basis of
this group. The position of the remaining species varies between
studies and is effectively unresolved. Many studies place the
snow leopard within the genus Panthera but there is no consensus
whether the scientific name of the snow leopard should remain
Uncia uncia or be moved to Panthera uncia.
Based on morphological evidence, British zoologist Reginald
Pocock concluded that the jaguar is most closely related to the
leopard. However, DNA evidence is inconclusive and the position
of the Jaguar relative to the other species varies between
studies. Fossils of extinct Panthera species, such as the
European jaguar (Panthera gombaszoegensis) and the American lion
(Panthera atrox), show characteristics of both the lion and the
jaguar. Analysis of jaguar mitochondrial DNA has dated the
species lineage to between 280,000 and 510,000 years ago, later
than suggested by fossil records.
The last taxonomic delineation of the jaguar subspecies was
performed by Pocock in 1939. Based on geographic origins and
skull morphology, he recognized 8 subspecies. However, he did
not have access to sufficient specimens to critically evaluate
all subspecies, and he expressed doubt about the status of
several. Later consideration of his work suggested only 3
subspecies should be recognized.
Recent studies have also failed to find evidence for well
defined subspecies, and are no longer recognized. Larson (1997)
studied the morphological variation in the jaguar and showed
that there is clinal north–south variation, but also that the
differentiation within the supposed subspecies is larger than
that between them and thus does not warrant subspecies
subdivision. A genetic study by Eizirik and coworkers in 2001
confirmed the absence of a clear geographical subspecies
structure, although they found that major geographical barriers
such as the Amazon River limited the exchange of genes between
the different populations. A subsequent, more detailed, study
confirmed the predicted population structure within the
Colombian jaguars.
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The jaguar is a compact and well-muscled animal. There are
significant variations in size: weights are normally in the
range of 56–96 kilograms (124–211 lb). Larger animals have been
recorded as weighing 131–151 kilograms (288–333 lb) (roughly
matching a tigress or lioness), and smaller ones have extremely
low weights of 36 kilograms (80 lb). Females are typically
10–20% smaller than males. The length of the cat varies from
1.62–1.83 meters (5.3–6 feet), and its tail may add a further 75
centimeters (30 in). It stands about 67–76 centimeters (27–30
in) tall at the shoulders.
Further variations in size have been observed across regions and
habitats, with size tending to increase from the north to south.
A study of the jaguar in the Chamela-Cuixmala Biosphere Reserve
on the Mexican Pacific coast, showed ranges of just 30–50
kilograms (66–110 lb), about the size of the cougar. By
contrast, a study of the Jaguar in the Brazilian Pantanal region
found average weights of 100 kilograms (220 lb). Forest Jaguars
are frequently darker and considerably smaller than those found
in open areas (the Pantanal is an open wetland basin), possibly
due to the fewer large herbivorous prey in forest areas.
A short and stocky limb structure makes the jaguar adept at
climbing, crawling and swimming. The head is robust and the jaw
extremely powerful. It has been suggested that the jaguar has
the strongest bite of all felids, and the second strongest of
all mammals; this strength is an adaptation that allows the
jaguar to pierce turtle shells. A comparative study of bite
force adjusted for body size ranked it as the top felid,
alongside the clouded leopard and ahead of the lion and tiger.
It has been reported that "an individual jaguar can drag a 360
kg (800 lb) bull 8 m (25 ft) in its jaws and pulverize the
heaviest bones". The jaguar hunts wild animals weighing up to
300 kilograms (660 lb) in dense jungle, and its short and sturdy
physique is thus an adaptation to its prey and environment.
The base coat of the jaguar is generally a tawny yellow, but can
range to reddish-brown and black. The cat is covered in rosettes
for camouflage in its jungle habitat. The spots vary over
individual coats and between individual Jaguars: rosettes may
include one or several dots, and the shape of the dots varies.
The spots on the head and neck are generally solid, as are those
on the tail, where they may merge to form a band. The
underbelly, throat and outer surface of the legs and lower
flanks are white.

A condition known as melanism occurs in the species. The
melanistic form is less common than the spotted form—six percent
of jaguars in their South American range have been reported to
possess it—and is the result of a dominant allele. Jaguars with
melanism appear entirely black, although their spots are still
visible on close examination. Melanistic Jaguars are informally
known as black panthers, but do not form a separate species.
Rare albino individuals, sometimes called white panthers, occur
among jaguars, as with the other big cats.
The jaguar closely resembles the leopard, but is sturdier and
heavier, and the two animals can be distinguished by their
rosettes: the rosettes on a jaguar's coat are larger, fewer in
number, usually darker, and have thicker lines and small spots
in the middle that the leopard lacks. Jaguars also have rounder
heads and shorter, stockier limbs compared to leopards.
Jaguar females reach sexual maturity at about two years of age,
and males at three or four. The cat is believed to mate
throughout the year in the wild, although births may increase
when prey is plentiful. Research on captive male jaguars
supports the year-round mating hypothesis, with no seasonal
variation in semen traits and ejaculatory quality; low
reproductive success has also been observed in captivity. Female
estrous is 6–17 days out of a full 37-day cycle, and females
will advertise fertility with urinary scent marks and increased
vocalization. Both sexes will range more widely than usual
during courtship.
Mating pairs separate after the act, and females provide all
parenting. The gestation period lasts 93–105 days; females give
birth to up to four cubs, and most commonly to two. The mother
will not tolerate the presence of males after the birth of cubs,
given a risk of infant cannibalism; this behavior is also found
in the tiger.
The young are born blind, gaining sight after two weeks. Cubs
are weaned at three months but remain in the birth den for six
months before leaving to accompany their mother on hunts. They
will continue in their mother's company for one to two years
before leaving to establish a territory for themselves. Young
males are at first nomadic, jostling with their older
counterparts until they succeed in claiming a territory. Typical
lifespan in the wild is estimated at around 12–15 years; in
captivity, the jaguar lives up to 23 years, placing it among the
longest-lived cats.
Like most cats, the jaguar is solitary outside mother-cub
groups. Adults generally meet only to court and mate (though
limited non-courting socialization has been observed
anecdotally) and carve out large territories for themselves.
Female territories, from 25 to 40 square kilometers in size, may
overlap, but the animals generally avoid one another. Male
ranges cover roughly twice as much area, varying in size with
the availability of game and space, and do not overlap. Scrape
marks, urine, and feces are used to mark territory.
Like the other big cats, the jaguar is capable of roaring (the
male more powerfully) and does so to warn territorial and mating
competitors away; intensive bouts of counter-calling between
individuals have been observed in the wild. Their roar often
resembles a repetitive cough, and they may also vocalize mews
and grunts. Mating fights between males occur, but are rare, and
aggression avoidance behaviour has been observed in the wild.
When it occurs, conflict is typically over territory: a male's
range may encompass that of two or three females, and he will
not tolerate intrusions by other adult males.
The jaguar is often described as nocturnal, but is more
specifically crepuscular (peak activity around dawn and dusk).
Both sexes hunt, but males travel further each day than females,
befitting their larger territories. The jaguar may hunt during
the day if game is available and is a relatively energetic
feline, spending as much as 50–60% of its time active. The
jaguar's elusive nature and the inaccessibility of much of its
preferred habitat make it a difficult animal to sight, let alone
study.
Like all cats, the jaguar is an obligate carnivore, feeding only
on meat. It is an opportunistic hunter and its diet encompasses
85 species. The jaguar prefers large prey and will take deer,
tapirs, peccaries, dogs, and even anacondas and caiman. However,
the cat will eat any small species that can be caught, including
frogs, mice, birds, fish,
sloths, monkeys, turtles,
capybara, and domestic livestock.
While the jaguar employs the deep-throat bite-and-suffocation
technique typical among Panthera, it prefers a killing method
unique amongst cats: it pierces directly through the temporal
bones of the skull between the ears of prey (especially the
Capybara) with its canine teeth, piercing the brain. This may be
an adaptation to "cracking open" turtle shells; following the
late Pleistocene extinctions, armored reptiles such as turtles
would have formed an abundant prey base for the jaguar. The
skull bite is employed with mammals in particular; with reptiles
such as caiman, the jaguar may leap on to the back of the prey
and sever the cervical vertebrae, immobilizing the target. While
capable of cracking turtle shells, the jaguar may simply reach
into the shell and scoop out the flesh. With prey such as dogs,
a paw swipe to crush the skull may be sufficient.
The jaguar is a stalk-and-ambush rather than a chase predator.
The cat will walk slowly down forest paths, listening for and
stalking prey before rushing or ambushing. The jaguar attacks
from cover and usually from a target's blind spot with a quick
pounce; the species' ambushing abilities are considered nearly
peerless in the animal kingdom by both indigenous people and
field researchers, and are probably a product of its role as an
apex predator in several different environments. The ambush may
include leaping into water after prey, as a jaguar is quite
capable of carrying a large kill while swimming; its strength is
such that carcasses as large as a heifer can be hauled up a tree
to avoid flood levels.
On killing prey, the jaguar will drag the carcass to a thicket
or other secluded spot. It begins eating at the neck and chest,
rather than the midsection. The heart and lungs are consumed,
followed by the shoulders. The daily food requirement of a 34
kilogram animal, at the extreme low end of the species' weight
range, has been estimated at 1.4 kilograms. For captive animals
in the 50–60 kilogram range, more than 2 kilograms of meat daily
is recommended. In the wild, consumption is naturally more
erratic; wild cats expend considerable energy in the capture and
kill of prey, and may consume up to 25 kilograms of meat at one
feeding, followed by periods of famine.
The jaguar has been attested in the fossil record for two
million years and it has been an American cat since crossing the
Bering Land Bridge during the Pleistocene; the immediate
ancestor of modern animals is Panthera onca augusta, which was
larger than the contemporary cat. Its present range extends from
Mexico, through Central America and into South America,
including much of Amazonian Brazil. The countries included in
this range are Argentina, Belize, Bolivia, Brazil, Colombia,
Costa Rica, Ecuador, French Guiana, Guatemala, Guyana, Honduras,
Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, U.S. and
Venezuela. The jaguar is now extinct in El Salvador and Uruguay.
The largest protected jaguar habitat is the 400 square kilometer
Cockscomb Basin Wildlife Sanctuary in Belize.
The inclusion of the United States in the list is based on
occasional sightings in the southwest, particularly in Arizona,
New Mexico and Texas. In the early 1900s, the jaguar's range
extended as far north as Southern California and western Texas.
The jaguar is a protected species in the United States under the
Endangered Species Act, which has stopped the shooting of the
animal for its pelt. In 2004, wildlife officials in Arizona
photographed and documented jaguars in the south of the state.
For any permanent population to thrive in Arizona, protection
from killing, an adequate prey base, and connectivity with
Mexican populations are essential.
The historic range of the species included much of the southern
half of the United States, and in the south extended much
farther to cover most of the South American continent. In total,
its northern range has receded 1000 kilometers southward and its
southern range 2000 km northward. Ice Age fossils of the jaguar,
dated between 40,000 and 11,500 kya, have been discovered in the
United States, including some at an important site as far north
as Missouri. Fossil evidence shows jaguars of up to 190 kg (420
lb), much larger than the contemporary average for the animal.
The habitat of the cat includes the rain forests of South and
Central America, open, seasonally flooded wetlands, and dry
grassland terrain. Of these habitats, the jaguar much prefers
dense forest; the cat has lost range most rapidly in regions of
drier habitat, such as the Argentinian pampas, the arid
grasslands of Mexico, and the southwestern United States. The
cat will range across tropical, subtropical, and dry deciduous
forests (including, historically, oak forests in the United
States). The jaguar is strongly associated with water and it
often prefers to live by rivers, swamps, and in dense rainforest
with thick cover for stalking prey. Jaguars have been found at
elevations as high as 3800 m, but they typically avoid mountain
forest and are not found in the high plateau of central Mexico
or in the Andes.
A jaguar in a wildlife rescue & rehabilitation centre in
Argentina.The jaguar is an apex predator, meaning that it exists
at the top of its food chain and is not regularly preyed on in
the wild. The jaguar has also been termed a keystone species, as
it is assumed, through controlling the population levels of prey
such as herbivorous and granivorous mammals, apex felids
maintain the structural integrity of forest systems. However,
accurately determining what effect species like the jaguar have
on ecosystems is difficult, because data must be compared from
regions where the species is absent as well as its current
habitats, while controlling for the effects of human activity.
It is accepted that mid-sized prey species see population
increases in the absence of the keystone predators and it has
been hypothesized that this has cascading negative effects,
however, field work has shown this may be natural variability
and that the population increases may not be sustained. Thus,
the keystone predator hypothesis is not favoured by all
scientists.
The jaguar also has an effect on other predators. The jaguar and
the cougar, the next largest feline of the Americas, are often
sympatric (related species sharing overlapping territory) and
have often been studied in conjunction. Where sympatric with the
jaguar, the cougar is smaller than normal. The jaguar tends to
take larger prey and the cougar smaller, reducing the latter's
size. This situation may be advantageous to the cougar. Its
broader prey niche, including its ability to take smaller prey,
may give it an advantage over the jaguar in human-altered
landscapes; while both are classified as near-threatened
species, the cougar has a significantly larger current
distribution.

This Jaguar Page is Copyright The Animal Web Guide © 2004 - 2009 Chuck Ayoub