Jaguar
Panthera onca
Description and Behavior
The jaguar is the only big cat of the Americas. Jaguars have the strongest jaw of all felines, and second strongest bite of any mammal, which allow them to eat things like turtles. Melanism is frequent in the jaguar, and is inherited as a dominant rather than a recessive allele (only black jaguars give birth to black cubs). The size difference may be due to the greater abundance of large prey species in more open environments. Jaguars are primarily nocturnal, but may often be active during dawn and dusk (crepuscular) or during the day. Jaguars have been found to be active for 50-60% of each day. The jaguar is a strong swimmer, and is strongly associated with the presence of water.
There are many differences between jaguars and leopards. The jaguar’s pattern differs from that of the leopard by having larger, broken-edged rosettes around small black spots. The jaguars build is also very different. It has a large head and stocky build, with relatively shorter limbs than other big cats (the “bulldog” of the big cats). Leopards are very lean.
Prey
More than 85 species have been recorded in the jaguar’s diet. Large prey, such as peccaries, tapirs and deer, may be preferred, but a jaguar will eat almost anything it can catch, and the more abundant a prey item, the more often it will prey upon it. Jaguars living in open habitats will more often prey upon large herbivores found in these types of habitats. Jaguars are the only big cat that will actively hunt on land, in the trees and in the water. In many areas, cattle are ranched on what is essentially prime jaguar habitat, and cattle have been the most frequent prey species documented in several analyses of jaguar diet in Brazil.
Jaguars are the only big cats which regularly kill prey 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.
Habitat
Hugely variable, but strongly associated with water; rainforest, seasonally flooded swamp, pampas grassland, thorn scrub woodland, to dry deciduous forest. Typically not found in mountain regions (over 2,700 feet)
Range
The historical range of the jaguar extended from Arizona, New Mexico and Texas in the United States south to either the Negro River or Santa Cruz River in Argentina. Now found in portions of Mexico, Central and South America.
Biology
| Weight | 100-225 lb |
| Reproductive Season | Probably year-round, but young are usually born in the rainy season when prey is more abundant
|
| Gestation Period | Average 101, range 91 -111 days
|
| Litter Size | 1-4 cubs, usually 2
|
| Age at Independence | |
| Sexual Maturity | Females 2-3 years; males - 3-4 years
|
| Longevity | 11-12 years in the wild; over 20 years in captivity
|
| Social Structure | Solitary, except for family groups
|
Principal Threats
Loss of habitat isolates jaguar populations so that they are more vulnerable to the predations of man, and to loss of genetic diversity (largest threat to jaguar population) People compete with jaguars for prey, and jaguars are frequently shot on sight, despite protective legislation.
Commercial hunting and trapping of jaguars for their pelts has declined drastically since the mid-1970s, when anti-fur campaigns gathered steam and CITES controls progressively shut down international markets. Poaching is not a threat.
Jaguars face local extirpation at the hands of cattle ranchers. The most urgent conservation issue is the current intolerance of ranchers for jaguars. In many cattle-ranching operations in the region, livestock roam widely and become essentially feral. Cattle have been shown to constitute a major portion of jaguar diet in studies carried out on ranches in seasonally flooded savanna woodland. The vulnerability of the jaguar to persecution is demonstrated by its disappearance by the mid-1900s from the southwestern US and northern Mexico. A conservation plan has been developed for jaguars in Brazil, and the Brazilian government is planning to establish a National Center for Research, Management, and Conservation of Predators in Brazil to address livestock-predator problems. Controlled sport hunting may be an important element of national jaguar conservation strategies, arguing that trophy fees would be an incentive for some ranchers to maintain jaguars on their land. Relocation of problem jaguars has also been recommended, but preliminary research suggests that relocated jaguars return to stock killing in their new range.
Role in Environment
Umbrella species – conservation of rainforest
|
