Chimpanzee Mating Behavior

Chimpanzees live in social groups, which set the tone of their usual mating behaviors. But, these very social groups can also be unpredictable, according to the Primate Info Net website. Many factors influence a chimpanzee’s mating behavior, including how much food is available to the group and how many chimps are in the group at any given time.

  1. Males Have Preferred Mates

    • When it comes to preferring older versus younger women, chimpanzees are much more open to the suggestion than are their male primate cousins, human males. In fact, research by Martin Muller of Boston University, reported in the November 2006 issue of Current Biology, shows that chimps actually prefer older females to young ones. Researchers speculate that the reason male chimpanzees tend to prefer older females is because chimpanzees are promiscuous. Humans form long-term mating bonds. Therefore, young females are more valuable mates for human males than older females are because of their greater reproductive potential. Since chimpanzees are promiscuous, it doesn’t matter what the age of the female is, as long as she can still reproduce. In fact, males prefer old, balding females with worn and broken teeth over young, healthy females, according to a Current Biology report summarized on Science Daily.

    Chimpanzees Live in Groups

    • Chimps have a high rate of copulatory success partly because they live in groups and have easy access to mates, according to the Primate Info Net website. Groups that chimps live in vary in size and can be highly fluid with different members coming and going. But when estrous females--females who are going through ovulation--are present, the group size increases. Estrous females are very social.

    When Mating Begins

    • Male chimpanzees can reproduce beginning at 16 years. Estrus in females starts at 10 years, at which time their anus and genitals swell. Menarche begins a few months after the swelling. Then, females go through a two- to four-year period during which they are infertile. They still exhibit swelling so that male chimps will accept them into their community. Female chimps will typically have their first baby when they are 13 or 14. They wait three to five years before giving birth again.

    Infertile Period of Female Chimpanzees

    • Female chimps go through the infertile period to give them time for the males to accept them in their social group. If a female has offspring before the males accept her in the group, this could jeopardize the life of her baby. Males kill infants unless they know they are their own, according to Primate Info Net website.

    Types of Mating Strategies

    • Although male and female chimpanzees are promiscuous, other strategies occur. Restrictive mating is when the dominant male keeps other males away from his mate during estrous. Consortship mating is when an adult pair leaves the community together for a few days or weeks. Extra-group mating is when females leave their community and mate with males from nearby communities.