Panthera Onca Research Paper

Life History of Animalia Chordata Mammalia Carnivora Felidae Panthera onca (Linnaeus, 1758)

Kala Rene John
BIO 1301 Biology of Animals Laboratory Fall 2013
Professor Jerry L. Farris
Arkansas State University

General Appearance Panthera onca is the largest feline in the New World (Seymour 1989). The felid is closely related to the leopard (Panthera pardus) in most senses but differs in many areas such as size. P. onca has a larger average body size, approximately 1.12 m to 1.85 m from head to tail (Seymour 1989). Specifically, females average from 1.57 m to 2.19 m in length while males average 1.72 m to 2.41 m in length (Seymour 1989). Shoulder height is overall 0.68 m to 0.75 m on average (Seymour 1989). This makes females
generally 10% to 20% smaller than males (Seymour 1989). P. onca have muscular, deep-chested bodies with relatively short, massive limbs (Seymour 1989). The mass of females are on average 56.3 kg and 95.0 kg for males (Seymour 1989). The species’ tail is more tapered, the body is heavier, more compact, and powerfully built than P. pardus (Seymour 1989). P. onca has larger, shorter canine teeth, a more robust head, and larger rounder footpads than that of its brother, P. pardus (Seymour 1989). Since the head is rounder and stouter, it is relatively short and broad, more so in males than females (Seymour 1989). The sagittal crest on the skull becomes more prominent in males and older individuals (Seymour 1989). As for coloring, P. onca can come in a variety of colors. The colors range from pale yellow to tan to black or reddish yellow (Seymour 1989). The cheeks, sides of the neck, throat, outer parts of the legs, and the lower flanks are more white (Seymour 1989). Although the color on one species is usually uniform throughout, some may develop rosettes (Seymour 1989). The rosettes (rose-like spots developed for camouflage) that spot the fur of P. onca are similar to that of P. pardus, but enclose one or more black spots closer to the flank end (Seymour 1989). Along the back, the spots tend to merge and become long and black with similar spotting on the flanks (Seymour 1989). The spots are solid black on the head and neck while the tail is white underneath with two or three black rings near the end with a black tip (Seymour 1989). Spotting is very random and can even differ from the right side to the left side (Seymour 1989). P. onca ears are black on the back, rounded, and small (Seymour 1989). There are small white central spots on the front of the ears (Seymour 1989). The fur covering the species in short and bristly while the throat, stomach, chest, and interior parts of the paws generally have longer fur (Seymour 1989). There are multiple color variations to the species, P. onca, although all variations are well understood and easily observable.
Range
The species does not have a very wide range throughout the world. P. onca is distributed over a range of 8.75 million km2 broken up into 48 different areas (Sanderson et al. 2002). P. onca mainly live in dense forests near water, therefore mainly tropical areas and are rarely found in altitudes over 1,000 m (Seymour 1989).The species ranges from three isolated observations in the southwestern United States all the way to southern South America with northern Mexico, northern Brazil, southern Argentina, and Guatemala (Sanderson et al. 2002, Seymour 1989). Because of hunting, P. onca has been completely wiped out from the Argentine Monte, Pampas grasslands in southern South America, western gulf coastal grasslands in the United States, El Salvador, Uruguay, and the developed areas of the Brazilian coast (Sanderson et al. 2002, Seymour 1989). The largest remaining population (88% of occupied range) currently resides in the Amazonian rainforest, Amazon Basin in Brazil (Sanderson et al. 2002, Seymour 1989). However, P. onca live in dense, dark forests, are secretive and nocturnal, making them difficult to census.
Habitat
As was said before, P. onca primarily live in dense, dark forests that are close to water. This would mean that their areas are mostly tropical. However, P. onca has been reported to live within many different habitats (Seymour 1989). Although they primarily prefer areas with plant cover, water, and sufficient amounts of prey such as in a rainforest, they have also been recorded living in low-scrub jungles, swampy savannas, lagoons, deserts, marshlands, lowland semi-deciduous forest, thorn scrub, and floating islands of vegetation (Seymour 1989). P. onca are able to live within a variety of habitats due to the fact that they are able to utilize every vegetation type (Seymour 1989). Within their habitats, jaguars will use dens, especially when rearing young; adults that are not breeding will also create dens inside of caves (Seymour 1989). The species seems very versatile in its living arrangements and how it is able to adapt to the environment.
Diet
P.
onca also has a varying diet, perhaps due to the fact that the habitats differ. Most jaguars are solely carnivorous while some will eat grass; avocados have been recorded as an apparent favorite of the species (Seymour 1989). As for the carnivore side of the species, the chief prey is any terrestrial mammal over 1 kg in body mass (Seymour 1989). However, reptiles and birds are also favored (Seymour 1989). Varied examples include: capybaras (Hydrochoerus), pacas (Agouti paca), armadillos (Dasypus), caimans (Caiman), turtles (Podocnemis), opossums (Didelphis), monkeys (Alouatta seniculus, Aotus trivigatus), otters (Lutra), ocelots (Felis pardalis), anteaters (Myrmecophaga, Tamandua), tortoises (Geochelone), storks (Jabiru mycteria), catfish (Pseudoplatystoma fasciatum), sloths (Bradypus, Choloepus), and frogs (Ranidae) (Seymour 1989). P. onca will take down brocket deer and marsh deer, whereas they rarely take deer in general, a contrast to the puma (Seymour 1989). Because the habitats vary, P. onca are opportunistic feeders, especially in rain forests where they catch prey that is easily available and ready (Seymour 1989). This makes their diets dependent on prey density within their respective habitat. Also, it has been observed that individual P. onca can have prey preferences, especially in livestocks of cattle, horses, pigs, or dogs (Seymour
1989).

Literature Cited
Seymour, K. 1989. Panthera onca (Linnaeus 1758). American Society of Mammologists. Mammalian Species 340: 1-9.
Sanderson, E.W., K.H. Redford, C.B. Chetkiewicz, R.A. Medellin, A.R. Rabinowitz, J.G. Robinson, and A.B. Taber. 2002. Planning to Save a Species: the Jaguar as a Model. Conservation Biology 16: 58-72.