Fig. 1.
Age-specific mortality at age x, ux, for each study species, illustrating high infant mortality, low juvenile mortality, and mortality increasing with age over the adult life span. No sex-specific first-year mortality estimates are available for sifaka because individuals were not sexed and individually identified until their first birthday. For blue monkey males and both sexes of capuchins and muriquis, mortality estimates extend only through age 6, 20, and 32 years, respectively; in each case, this is much less than the suspected full life span, making it difficult to estimate the shape of the mortality curve at the end of life.