We examined demographic records from 13 captive primate species and a human population to determine age-related changes in
female reproduction. In most species age-specific fertility declined and interbirth intervals increased with age. Using an
operational definition of termination of reproduction based on individual variance in interbirth intervals, a proportion of
females in most nonhuman species had terminated reproduction before death. Compared to other primates, a greater proportion
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 quantify the extent of reproductive termination
and thereby extend hitherto anecdotal accounts of this phenomenon in primates.
Key words age-specific fertility - interbirth interval - life history - menopause - postreproductive life span