The Jaguar is the largest cat of the Americas, and the only living representative of the genus Panthera
found in the New World. The jaguars pattern differs from that of the leopard by having larger, broken-edged
rosettes around small black spots. It has a large head and stocky build, with relatively shorter limbs
than others of its genus. The jaguar can reach a length of 7 feet from nose to tail tip and stands about
28 inches at the shoulder. An adult male jaguar may weigh 250 pounds while the female reaches about 200
pounds. Melanism is frequent in the jaguar, and is inherited as a monogenic dominant to the normal golden-colored
form, rather than through a recessive allele. Albinistic specimens are occasionally reported. Forest
jaguars are not only more frequently darker, but are also considerably smaller in size than animals which
inhabit more open areas. The size difference may be due to the greater abundance of large prey species
in more open environments.
Jaguars usually mate in January. Two to four young are born about
110 days later. The cubs will stay with their mother until they are about 15 months of age. Sexual
maturity comes at about 18 months of age for females, and at around 24 months for males. Jaguars may
live for about 20 years in the wild, and have been known to live for 30 years in captivity.
more than 85 species have been recorded in the jaguars diet Large prey, such as peccaries,
tapirs and deer, may be preferred, but a jaguar will eat almost anything it can catch, and in the rainforest
will take mammal prey species in proportion to their occurrence. Large herbivores are more thinly distributed
in rainforest than in more grassy, open habitats, where they are more likely to form groups and cluster
near water, and jaguar diet in the rainforest and in savanna woodlands reflects this difference in prey
availability and vulnerability. In many areas, cattle are ranched on what is essentially prime jaguar
habitat, and cattle have been the most frequent prey species.
Jaguars are the only
big cats which regularly kill prey (especially capybaras) by piercing the skull with their canines.
Emmons (1987) suggests that the massive head and stout canines of the jaguar are an adaptation to "cracking
open" well-armored reptilian prey, such as land tortoises and river turtles. She notes that, following
the late pleistocene extinctions of large herbivores, the jaguar and the puma were the only representatives
of five genera of North American felid to persist, and speculates that the jaguar evolved to take advantage
of a formerly super-abundant prey base of water reptiles.
Although the jaguar has
been characterized as primarily nocturnal, radiotelemetry studies have shown that they are often active
during the daytime, with activity peaks around dawn and dusk. Jaguars have been found to be active for
50-60% of each 24-hour period.
The jaguar, which swims well, is strongly associated with the
presence of water. Habitats meeting this requirement range from rainforest to seasonally flooded swamp
areas (Pantanal and Llanos), pampas grassland, thorn scrub woodland (Chaco), and dry deciduous forest.
In Belize, it has been found that jaguars were more abundant in lowland areas of relatively dense forest
cover with permanent water sources than in open, seasonally dry forests. In the Brazilian Pantanal, riparian
forest was strongly preferred to open grassy areas. Although jaguars have been reported from elevations
as high as 3,800 m, jaguars typically avoid montane forest, and have not been found in the high plateau
of central Mexico, or above 2,700 m in the Andes. The historical range of the jaguar extended from Arizona,
New Mexico and Texas in the United States south to either the Rmo Negro (400S) or Rmo Santa Cruz (500S)
in Argentina. Formerly occupied habitat in the north of its range included oak woodland, mesquite thickets
and riparian forests. In the north, the jaguars range has receded southward about 1,000 km, and has
been reduced in area by about 67%. In South America, the jaguars range has receded northward by well
over 2,000 km, and has been reduced by about 38%.
