Jaguar, Panthera onca
The jaguar is the largest cat in the Americas and is the only living representative of the genus Panthera found in the New World. The largest jaguars have been found in the Brazilian Pantanal region, with a record weight of over 347 pounds (158kg). Jaguars living in heavily forested areas are considerably smaller than those from populations in more open areas like the Pantanal of
Brazil and the Llanos of Venezuela. In one study, the average weight of males was 220 pounds (100kg). Head and body length, without the tail may be up to six feet (1.85m), and the tail can measure 30 inches (75cm) more. Height at the shoulder may be up to 30 inches (75cm). The jaguar’s coat color ranges from pale yellow to reddish brown, with a much paler (often white) underbelly. It has spots on the neck, body and limbs that form rosettes, which contain black markings within them. On the head and underparts, the spots are simple black dots. Black jaguars are not uncommon, and even they possess darker rosette markings that are visible in bright light. Compared to a leopard, the jaguar is stocky and more powerfully built. The square jaw and prominent cheeks, along with robust, muscular limbs give evidence of immense strength. It has been said that the jaguar is built for power, not speed. While true, this cat also demonstrates surprising stealth and grace in movement.
Habitat is variable for the species. Major habitats include grassland, lowland tropical rainforest, temperate broadleaf forest, tropical monsoon and dry forest and tropical savannah woodland. They are also found in lesser numbers in succulent and thorn scrub woodland and dry deciduous forest. Jaguars have been found at elevations as high as 12,467 feet (3,800 m) in Costa Rica, but typically avoid montane forest and have not been found in the high plateau of central Mexico or above 8,858 feet (2,700 m) in the Andes.
First appearing in the fossil record around 2 million years ago, the jaguar has been an American species at least that long. Found throughout what is now the southern United States until about 10,000 years ago, it was eliminated from the United States around 1900. In the late 1990s, several sightings in Arizona occurred, prompting renewed interest in the jaguar’s northernmost habitat and distribution. The southern edge of its range is now in northern Argentina, but once extended into Uruguay. Range countries include Argentina, Belize, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, United States, Venezuela. It is now extinct in El Salvador and Uruguay.
The jaguar is a primary predator at the top of any ecological community in which it resides. Over 85 species have been recorded in the jaguar’s diet. Large prey such as peccary, deer, tapir and capybara are favored, but jaguars will eat almost anything that can be caught. In areas where cattle ranching is widespread, domestic livestock may become the most frequently targeted prey species.
Except when raising cubs, jaguars are solitary, territorial carnivores. Females seem to inhabit home ranges of about 15 to 23 mi2 (25 to 38km2). Ranges overlap somewhat, and resident males inhabit territories about twice that size, patrolling through the ranges of several females at a time. Males are sexually mature in three to four years, females in two to three years. Females have an estrous cycle of approximately four weeks and can breed at any time of year. Gestation is listed as between 93 and 105 days. Litter size is usually fewer than four cubs. Life expectancy in captivity is among the longest of any cat, and lifespans of up to 30 years have been recorded.
Traditionally thought of as being nocturnal, radio-collar tracking indicates that jaguars are active around-the-clock but mostly in the hours around sunrise and sunset. The jaguar patrols its territory or home range searching for food. Jaguars are the only big cat which regularly kills prey (especially capybaras) by piercing and crushing the skull with their canines. An excellent climber, jaguars make good use of trees. They often drag kills to a secluded or sheltered spot for consumption but do not cover or bury them, as cougars do.
It has been said that the jaguar is the only big cat that does not roar, but this is incorrect. The jaguar has an array of vocalizations including mews, grunts and a deep, repetitive “coughing” roar.
Threats to Survival
Major threats to the species are population fragmentation, deforestation and deliberate elimination. Although once heavily hunted for their skins, this threat has declined drastically since the mid-1970’s when anti-fur campaigns reduced the popularity of coats made from spotted cats and CITES controls progressively shut down international markets.
Today, most populations are threatened by high deforestation rates. This fragments jaguar populations and makes them more vulnerable to continuing persecution by man. Regardless of legal protection, jaguars are often shot on sight, especially in areas possessing cattle ranches. Because jaguars consume a large amount of cattle in their diet (where cattle are abundant), some farmers employ hunters to pursue local jaguars and today such conflict is the most urgent conservation issue facing this species. Translocation of problem animals has been attempted in Brazil and Venezuela but with inconclusive results. Attempts to relocate problem individuals in Belize found that jaguars often return to stock killing.
The IUCN lists jaguars as Lower Risk, near-threatened, and the U.S. Fish & Wildlife Service lists jaguars as Endangered. Overall, it seems that jaguars are not in immediate peril of extinction. However, their current geographic range is somewhere between one-third and half its historical size.
The AZA Jaguar Species Survival Plan (SSP) encourages and supports conservation and education projects that promote the survival of the jaguar in nature. Until recently, jaguars in North American zoo collections were largely of unknown origin but, recently, wild- born individuals from Peru and Venezuela have been acquired. A separate genetic line from Mexico has also been imported and ultimately the SSP hopes to possess only jaguars that can be totally traced to some part of the wild. It is not the goal of the SSP to focus on a single subspecies of jaguar because of the relative abundance of some populations, especially in Amazonia, and because it appears likely that additional founders from range countries will be periodically available for years to come. The SSP’s target population for the North American zoo population is 120 individuals.
Jaguar SSP Coordinator
Stacey Johnson, San Diego Zoo
Jaguar SSP Education Advisor
Sunni Robertson, San Diego Zoo
Jaguars are difficult to study in the field but research in the Pantanal of southern Brazil, the llanos of central Venezuela and in the Cockscomb Mountains of Belize have shed light on many aspects of their behavioral biology. Although true protection is still lacking in most parts of their range, protection in the form of the Cockscomb Basin is unique in setting aside a large tract of land specifically for jaguars.