TERMINATION OF REPRODUCTION IN NONHUMAN AND HUMAN FEMALE PRIMATES

We examined demographic records from 13 captive primate species and a human population to determine age-related changes in female reproducti on. In most species age-specific fertility declined and interbirth int ervals increased with age. Using an operational definition of terminat ion of reproduction based on individual variance in interbirth interva ls, a proportion of females in most nonhuman species had terminated re production before death. Compared to other primates, a greater proport ion of chimpanzees and human females ceased reproduction, and humans, in particular were reproductively inactive for relatively longer than would be expected from their body weight. These empirical data quantif y the extent of reproductive termination and thereby extend hitherto a necdotal accounts of this phenomenon in primates.