Catagonus Wagneri - Chacoan Peccary
Photos by Christopher Yahnke, collection of the Field Museum of Natural History
There are three species of peccary in the world and Catagonus wagneri is the largest of them all. Male animals weigh approximately 30 to 40 kg and females slightly less at 30 to 38 kg except when they are pregnant (Handen, 1994). They stand on average 65 cm high at the shoulders and have a body length of 96 to 117 cm. C. wagneri have a mixed coloration of grays, browns, blacks, and white for their bristly fur with an especially dark dorsal line running down the back. An interesting feature of this peccary is that it lacks the dewclaw on its hind foot which other peccaries possess. Along with this the feet are smaller and the legs are longer than in other species, which is probably an adaptation to the dry and difficult environment that it lives in. C. wagneri also has a long skull with an hypsodont tooth morphology and a dental formula of I 2/3, C 1/1, P 3/3, M 3/3 for a total of 38. These peccaries also have a scent gland on their back above the tail which produces a milky white substance used in marking sent on objects and other peccaries. Overall, in C. wagneri it is very hard to distinguish the different sexes in the field, so there is no apparent sexual dimorphism (Raffo, 2000).
C. wagneri is native to the dry Gran Chaco region in South America. This is a region which covers 3 different countries; Paraguay, Argentina, and Bolivia which covers around 140,000 square km. As far as the distribution in Paraguay is concerned, C. wagneri is found in the western half of the country. The Gran Chaco region has few trees and vegetation, such as cactus and brushy grass that dwell in dry areas (Raffo, 2000). This is a region with an extreme climate. Sometimes temperatures range from 19F to 117F (Toone, 2002).
C. wagneri breeds during late spring and early summer and then on average about 2 to 3 young are born from September to January with a gestation period of 151 days. Often females will go somewhere other than the herd to give birth and then come back later with young that are ready to be active and move in under one week. In the wild it is thought that females breed when they are around 3 years old but it has been found that C. wagneri in captivity have conceived in under one year old. The young peccaries are very similar in their coloration to the adults (San Diego Zoo, 2001).
Ecology and Behavior:
C. wagneri has some interesting ways of communicating with other peccaries. One of the unique features mentioned earlier is the fact that they mark areas with their scent glands on their backs by rubbing on things such as trees in locations such as scat stations and areas frequented by multiple herds. This species is very territorial because different herds seem to generally stay away from each other and not much overlapping of home ranges occurs. Other than rubbing on objects, C. wagneri will also rub their heads on another individual’s scent gland. Sometimes, when these peccaries are fleeing from danger, the scent will be squirted out as they run. Most often herds are comprised of 1 to 10 individuals which are often extended family groups and are diurnally active (Nowak, 1997). For the most part, C. wagneri is not a very aggressive species and fighting among these animals is infrequent. A unique way in which C. wagneri has adapted to its environment is the process in which it eats some of its food. Because these animals live in a dry and semi arid environment, one of its sources for food is different species of cacti. In order to get past the spines, C. wagneri rolls the cactus around on the ground with its nose, breaking off the spines. They can then eat it without the problem of dealing with this annoying feature of cactus. C. wagneri also has a tough, two chambered stomach which is needed to digest the tough food that it so often has to eat (Raffo, 2000).
This peccary species was thought to be extinct until it was discovered in 1972. There are an estimated 5000 animals still living in the Gran Chaco region where they have to deal with hunting by humans and some problems with disease. Catagonus wagneri is listed as endangered and work is being done to conserve this unique species. C. wagneri is often easily hunted because one individual can be killed and then others in the group will stay around the body. They can than be easily shot as well. This could contribute to C. wagneri having decreasing numbers (Handen, 1994).
Raffo, E. 2000.”Catagonus wagneri” (On line), Animal Diversity Web. <http://animaldiversity.ummz.umich.edu/site/accounts/information/
Catagonus_wagneri.html. Account #259.
Handen, E. Cynthia. 1994. Current Status of the Tagua’ (Catagonus wagneri) in Paraguay. Der Zoologishe Garten. 6, S. 329-337.
Toone, William and Wallace, Michael. The Giant Chacoan Peccary – An outstanding example of adaptation to a subtropical dryland ecosystem. Tropical Conservancy 2002.
Nowak, M. Ronald. 1997. Chacoan Peccary. Walker’s Mammals of the World Online. www.press.jhu.edu. John Hopkins University Press.
<library.sandiegozoo.org>. Chacoan Peccary, Catagonus wagneri. 2001
Reference written by Jacob Holsclaw, Biol 378 (Mammalogy), University of Wisconsin – Stevens Point: Edited by Christopher Luddington. Page last updated March 4, 2005.