Science Fair Project Encyclopedia
Catagonus wagneri A peccary (also known by its Spanish name, Javelina) is a medium-sized mammal of the family Tayassuidae. Peccaries are related to pigs and hippopotami, but are found in the southwestern area of North America and throughout South America. It is sometimes erroneously said that they are members of the rodent order; they are not. Peccaries usually measure between 90 and 130 cm in length (3 to 4 feet), and a full-grown adult usually weighs between about 20 and about 40 kilograms (44 to 88 pounds).
People often confuse peccaries, which are found in the New World, with pigs that originated in the Old World, especially since some domestic pigs brought by European settlers have escaped over the years and now run wild in many parts of the United States. These feral pigs are popularly known as razorback hogs. Relatives of the Old World pigs include the Warthog of Africa. One of the ways to tell apart the two groups is the shape of the canine tooth, or tusk. In the Old World pigs the tusk is long and curves around on itself, whereas in the New World peccaries the tusk is short and straight. Peccaries are plant eaters and use their tusks for defense. By rubbing the tusks together they can make a chattering noise that warns potential predators to not get too close.
The only peccary in the United States is the Collared Peccary (Dicotyles tajacu). It is often found in dry arid habitats. It is sometimes called a "musk hog" because of its strong odor. In some areas of the Southwest they have become habituated to human beings and live in relative harmony with them in such areas as the suburbs of cities where there are still relatively large areas of brush and undergrowth to move through. They are generally found in troops of eight to 15 animals of various ages. They will defend themselves if they feel threatened but otherwise tend to ignore human beings.
A second species is the White-lipped Peccary (Tyassu pecari), which is found in the rainforests of Central and South America.
The third species, the Chacoan Peccary (Catagonus wagneri), is the closest living relative to the extinct Platygonus pearcei. It is found in the dry shrub habitat or Chaco of Paraguay, Bolivia and Southern Brazil. The Chacoan Peccary has the unusual distinction of having been first described based on fossils and was originally thought to be only an extinct species. In 1975 the animal was discovered to still be alive and well in the Chaco region of Paraguay. The species was well known to the native people.
Modern peccaries are social animals and often form herds. Over 100 individuals have been recorded for a single herd of White-lipped Peccaries, but Collared and Chacoan Peccaries usually form smaller groups. Such social behavior seems to have been the situation in extinct peccaries as well.
Peccaries have a long history in North America. They first appear in the early Oligocene, about 32 million years ago, and a variety of different species are present in faunas of different ages across the continent. Some of these extinct peccaries have been found at John Day Fossil Beds National Monument in Oregon and at Badlands National Monument in South Dakota.
Although they are common in South America today, peccaries did not reach that continent until about nine million years ago, when the Isthmus of Panama formed, connecting North America and South America. At that time, many North American animals — including peccaries, llamas and tapirs — entered South America, while some South American species, such as the ground sloths, migrated north.
Original source: National Parks Service: Hagerman Fossil Beds' Critter Corner by Dr. Greg McDonald (public domain).
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