The mighty jaguar (Panthera onca) is a large feline (the third largest in the world behind tigers and lions) which can grow to a height of 2.5 feet and a length of up to 8 feet. This cat can weigh up to 250 lbs,[3] with males generally being 10-20% larger than females. Due to the greater densities of large prey found in more open areas, jaguars found in open habitats tend to be larger than those in dense forests. It is a powerfully built predator, with large, square jaws and prominent cheeks. It possesses a lean body, with muscular limbs.[4] Ultimately, the jaguar is designed with power in mind, not speed, as it can only sustain high speeds for very brief periods of time. While all felines are powerful creatures, the jaguar is especially notable for its sheer strength. This animal’s most frightening feature is its powerful jaws, which house large canines used to puncture the skulls of large mammals and even the armor of sizable reptiles.[5] Possibly the most noticeable feature of this cat, however, is its amazing coat; its base colors range from pale yellow to reddish brown, with black, rosette-shaped spots covering the neck, body, and limbs. The underside of the animal is of a white coloration. There also exist melanistic jaguars which possess a base coat color of black, with dark spots still dimly visible in the black background of the coat.[6]

This feline species once possessed a great distribution, with the large cats roaming from the southern tip of South America to north of the region surrounding the U.S.-Mexico border. Today, however, significant numbers of these animals are found only in remote regions of South and Central America.[7] Specifically, the modern jaguar distribution is concentrated in the Amazon Basin and includes portions of the Cerrado, Pantanal, and Chaco areas to the south. The jaguar range continues north and east to the Caribbean coast of Venezuela and Guianas. Jaguars prefer dense, tropical lowland forests, since these environments offer plenty of cover for the predators. However, these cats can also be found in scrubland, reed thickets, coastal forests, swamps, and thickets. Unlike most other cats, jaguars are excellent swimmers and are thus usually found in habitats near bodies of water such as rivers, slow moving streams, lagoons, watercourses, and swamps. They tend to avoid arid environments and very high altitudes, though jaguars have been reported in altitudes as high as 3800 meters in Costa Rica. In northern Mexico and southwestern United States (in which they are very rare), jaguars can be found in oak woodlands, mesquite thickets, and riparian woodlands. These animals often lay in deep shade, thick vegetation, in caves, or under large rocks when resting (which can take place at any time of the day, though usually during mid-morning and afternoon). It is also common for them to rest near river banks, and they are often forced to rest in trees during flood seasons. Jaguars often stalk prey on the ground, using the dense vegetation of their surroundings to conceal them from view. They will also sometimes climb trees to hunt, as well as to escape from danger. All in all, jaguars require three habitat characteristics in order to support healthy populations: a supply of water, dense cover, and sufficient prey.[8]

Jaguars posses large home ranges of approximately 25-38 square km for females, and double that amount for males. However, the home ranges of adult males often encompass two or three female home ranges. These territories are marked by the scraping of trees, defecating and spraying urine on vegetation, and via vocalizations. The vocalizations (which are also used during times of mating) can be heard as grunting “uh’s” which increase in tone and power while decreasing in frequency between grunts. Due to their larger home ranges, males often travel farther distances than females, and both sexes travel farther during dry seasons than during wet seasons. Adult males will not tolerate the presence of other males in their territory.[9]

The jaguar is a solitary hunter which can be active at any point during the day (unlike other species of felines which often rest during the day). Nonetheless, the jaguar prefers to hunt in the darkness of night, allowing it to use dense cover to a greater effectiveness while taking advantage of its excellent vision.[10] These big cats are in no way picky about what they eat; over 85 different species have been reported in the diet of jaguars. Among their prey are peccaries, tapirs, deer, fish, large birds, capybaras, porcupines, snakes, and turtles. Not even caimans (crocodilians closely related to alligators) are safe from these daring cats. Jaguars are able to overcome many of these animals by pouncing on them from a concealed spot. The jaguar can then deliver a powerful bite to the neck of its prey and suffocate the victim (a common killing method among felines). However, as mentioned previously, the jaguar can also take advantage of its unusually powerful jaws in order to pierce the back of its target’s skull using its canine teeth, puncturing the brain and instantly killing its prey. It then drags its food to a secluded spot where it can eat in peace.[11]

Jaguars also have a reputation for being man-eaters, partly due to their aggressive nature. Though there are many stories about jaguars following men for miles through the jungle, it is likely that these are nothing more than cases of jaguars “escorting” humans out of their territory.[12] Furthermore, the fact that jaguars appear to possess no fear of humans and possess a wide distribution can also contribute to humans’ fears of these creatures. As humans, particularly farmers and ranchers, continue to intrude into the jaguars’ habitat, more and more violent interactions with these predators take place. It is nothing short of ironic, however, that it is these people who become upset over the killing of their livestock by jaguars, never realizing that the jaguar (being an apex predator) is simply programmed to take advantage of any new feeding opportunities whenever they present themselves.[13] Nonetheless, the jaguar is always considered the problem in these situations.

Although jaguars are generally solitary animals, they become surprisingly vocal during times of breeding (which can take place throughout the year, though it usually occurs from December to March). Jaguar estrus cycles are usually 37 days with estrus lengths of 6-17 days. Once females become sexually mature (at the age of 1-2 years) and enter estrus (indicated by lordosis, flehmen, rolling, and increased scent markings), they venture out of their territory and alert nearby males (which reach sexual maturity slightly later at the age of 2-3 years) with 5-7 loud grunts. The males then respond with hoarse and guttural vocalizations and make their way to the female. When more than two males reach the same female, competition ensures. Usually it is the larger and more powerful male that asserts his dominance and wins the right to breed. After mating, however, the female no longer tolerates the presence of any males. After a gestation period of 91-111 days, the female gives birth to anywhere from 1-4 offspring (with two cubs being the average litter size). Born with their eyes closed and with no proper way of defending themselves, the cubs are entirely dependent upon their mother. It is only once they are two weeks of age that the young cats finally open their eyes for the first time, and they nurse until they are 5-6 months old. Once they are weaned, the young jaguars begin to hunt with their mothers. They are still dependent on her for guidance, however, as well as from other predators. Once they reach the age of two years, they finally become independent and can fend for themselves.[14]

Jaguars are among the rarest of the big cats, as their population numbers have been drastically lowered due to several reasons. The primary challenges facing this species are massive conversion of their habitats for human economic interests, being shot or poisoned by livestock owners who are worried for the safety of their livestock, and the depletion of their natural prey base through overhunting. Both humans and jaguars prefer the same prey, large mammals. As a result, there is a certain level of competition between jaguars and rural people for food, a competition that can lead to disastrous consequences for the big cat.[15] The jaguar is also a victim of the fur trade. Since the early 1900’s, jaguars have been hunted for their pelts. Despite a decline of this hunting activity in the 1960’s, the number of pelts exported was still high. Regardless of the jaguar’s status as an endangered species, illegal trade and poaching still continues to reduce their population numbers. Although conservation efforts have taken place, this illegal activity continues to threaten the future of this beautiful cat.[16] However, there is still hope for the species. In March 2009, a court case concerning the protection of the jaguar was brought against the federal government by the organization Defenders of Wildlife. It was ruled in favor of Defenders of Wildlife, with the federal court for the district of Arizona ruling that endangered jaguars deserved the full protection of the Endangered Species Act. This ruling will require the U.S. Fish and Wildlife Service to consider developing a recovery plan or designating critical habitat for the jaguar.[17] As more people become aware of the needs of this incredible creature, the brighter the future of the jaguar becomes. In spite of its status as an endangered species, the future of the jaguar is no longer as bleak as it once was.

The jaguar is truly an awe-inspiring creature. From the days of ancient civilizations to the modern age, the jaguar has been renowned for its beauty and its might. This elusive creature, among the rarest of the big cats, has become the apex predator of an ecosystem teeming with formidable hunters due to its frightening power and stealthy abilities. Yet, unfortunately, these traits are not enough to save it from the damage man has caused the species. The number of these beautiful creatures has diminished over the years due to the unnecessary killing of jaguars carried out by man. Nonetheless, the jaguar’s fate is not sealed. The admiration for this incredible creature remains strong in many people today, and more and more are becoming aware of the jaguar’s need for help. Now, with the people aware of the jaguar’s man-made threats, conservation efforts may allow this mighty yet mysterious hunter to thrive once more.

» Mammalogy » Might and Mystique: The Amazon’s...
On November 19, 2011
By Cendan Luis
amazon, apex predator, big cats, breaking, endangered species, jaguar, pictures

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