Female reproductive aging in seven primate species: Patterns and consequences

Area of Science:

• Primate reproductive ecology
• Evolutionary biology
• Gerontology in wildlife

Background:

• Age-related declines in fertility are observed in many wild animal populations.
• Youngest and oldest reproducers often show reduced reproductive success compared to prime adults.
• Understanding the evolution and diversity of these age effects is crucial.

Purpose of the Study:

• To compare patterns and consequences of age-related changes in female reproductive performance.
• To investigate these patterns across seven long-term studied primate populations.
• To identify factors contributing to species-specific differences in age-related reproductive effects.

Main Methods:

• Longitudinal data collection over 29 to 57 years in seven primate populations.
• Analysis of age-specific fertility, interbirth intervals, and offspring survival.
• Examination of the effect of maternal age on daughters' age at first reproduction.

Main Results:

• Most primate species exhibited age effects on fertility and offspring performance.
• Six species showed longer interbirth intervals in younger or older females.
• Five species had lower offspring survival for offspring of oldest mothers; two species showed reduced survival for offspring of both youngest and oldest mothers.

Conclusions:

• Shared patterns and contrasts exist in age-related female fertility changes across nonhuman primates.
• Species-specific behaviors and life-history patterns likely explain observed differences.
• Maternal age impacts reproductive timing in daughters, particularly in species with female-biased dispersal.