Pan paniscus

Introduction

            Pan paniscus are commonly known as bonobos.  P. paniscus have sparked the interest of many people because of their peaceful nature and sexual behavior.  P. paniscus were isolated as an individual species in 1933, prior to which they were thought to be a subspecies of chimpanzees, or Pan troglodytes.  The studies of P. paniscus have provided a better understanding of how Homo sapien communication and social patterns may have evolved.

Taxonomy

            P. paniscus and P. troglodytes are the sole members of the genus Pan.  P. paniscus have a smaller torso and longer legs and arms, and are less aggressive than their genus mates.  Paleoanthropologists theorize based on fossil records that the genus’ Pan and Homo share a common ancestor that was more gorilla-like (Lockwood, et al., 2004).

            Adult males weigh 86 lbs on average and adult females weigh 68.3 lbs on average.  P. paniscus are born with their black hair and face and typically do not go bald with age, as opposed to P. troglodytes, whom often do.  P. paniscus are quadrupedal knuckle walking creatures, but also demonstrate brachiation and some bipedalism.  The life expectancies of P. paniscus are 40 years (Cawthon Lang, 2005).

Biology

            P. paniscus rely on a diet mainly consisting of fruit, but they are also known to consume seeds, sprouts, leaves, flowers, bark, stems, roots, and mushrooms.  Additionally, P. paniscus eat an array of small mammals, insect larvae, earthworms, honey, eggs, and soil.  P. paniscus are more opportunistic hunters than active hunters (Cawthon Lang, 2005).

Young females leave their dyads as juveniles to join new groups.  P. paniscus are known for their frequent mating, which can be solicited by males and females.  Certain males and females form close relationships in which they often conceive, though each individual mates with other individuals and paternity is always a mystery.  Conception within close relationship is usually due to frequent mating around the time of ovulation.  Forced mating is rare in P. paniscus due to the likelihood of retaliation by supporting males and females in the dyad (Hohmann, et al., 2003)

Female P. paniscus usually have their first offspring by 13 or 14 years of age, and there is an interbirth interval of four to six years.  The genitals of female P. paniscus swell at different stages, but ovulation has not been found to correlate with swelling size.  A peak birthing season falls during the light rainy season between March and May, which contributes to a decreased likelihood of infant mortality.  Mothers assume parental responsibility in P. paniscus society, and the infants remain in close proximity of their mothers for the first three years of life.  The infants are not weaned until around age four or five.  Though females leave their natal group and sever ties with their mothers, males remain in the same group as their mothers throughout their lives (Cawthon Lang, 2005).

Ecology

            P. paniscus live south of the Congo River in the Central Basin, in the tropical and subtropical forests of central Africa.  The territory inhabited by P. paniscus is roughly 135,000 km and bound by the Congo-Lualaba and the Kasa’i-Sankuru river systems.  Forest altitudes inhabited by P. paniscus vary from 300 to 700m.  The annual average temperature is 24.5 C.  The area is characterized by two dry seasons and two wet seasons and is often flooded (Ilambu, et al., 2005).

Current Topic

            P. paniscus are threatened by deforestation, poaching and diseases introduced by humans.  Deforestation is one of the Democratic Republic of the Congo’s few economical choices and many residents in urban areas have been forced back into the forest.  Loggers, soldiers, and forest residents harvest lumber for commercial and sustenance purposes, decreasing P. paniscus habit.  P. paniscus are also preyed upon for bushmeat and as pets.  Many people use P. paniscus meat for consumption and as currency in exchange for necessities such as clothing, medicine, and spices.  Infants are captured at the expense of sometimes 10 adults to be sold in the illegal pet industry.  Lastly, P. paniscus are also susceptible to human diseases including Ebola, herpes, poliovirus, hepatitis, and possibly leprosy.  Civil war has caused most research to cease until the area is stabilized, and in the process P. paniscus are left to fend for themselves (Cawthon Lang, 2005).

Conclusion

            P. paniscus have provided so many answers and understanding about evolution.  With such limited populations in a specific area, the threat towards P. paniscus is alarming.  There are no known predators of P. paniscus, making humans their only problem.  As long as laws go unenforced and people can live and hunt without any concern for P. paniscus, their numbers will continue to decline, and another of man’s distant relatives will disappear.

Literature Cited

Cawthon Lang, K.A.  (2005).  Primate Factsheets:  Bonobo (Pan paniscus) Taxonomy, Morphology, & Ecology.  http://pin.primate.wisc.edu/factsheets/entry/bonobo/taxon.  Accessed 2010 November 26.

Hohmann, G. and Fruth, B.  (2003).  Intra- and Inter-Sexual Aggression by Bonobos in the Context of Mating.  Behaviour.  140(11/12).  1389-143.

Ilambu, O. and Inogwabini, B.-I.  (2005).  A landscape-wide distribution of Pan-paniscus in the Salonga National Park, Democratic Repubic of Congo.  Endangered Species Update.  22(3).  116.

Lockwood, C.A., Kimbel, W.H., and Lynch, J.M.  (2004).  Morphometrics and hominoid phylogeny:  Support for a chimpanzee-human clade and differentiation among great ape subspecies.  PNAS.  101(13).  4356-4360.