Female life history and mating patterns among the M group chimpanzees of the Mahale national park,Tanzania

The mating behavior of receptive females in the M group chimpanzees (Pan troglodytes schweinfurthii) of the Mahale Mountains, western Tanzania, was studied by intensive sampling over a period of 5 months. Restrictive matings were observed only between parous females mostly in the ovulatory stage and prime adult males, in particular the alpha. Young, nulliparous and/or non-ovulatory females tended to mate with immature or low-ranking adult males. By contrast, older, parous and/or ovulatory females tended to mate with adult and higher-ranking males. These confirmed the results of a previous extensive study of the same group. In addition, gradual shift from opportunistic to restrictive matings after inter-unit-group transfer was revealed for 2 ex-K-group parous females. The findings were discussed in relation to the life history of female chimpanzees. A National Park since 1984.