Monkeying around: Study finds older primates father far fewer babies

Older male rhesus monkeys sire fewer offspring, even though they appear to be mating as much as younger monkeys with similarly high social status. Sperm quality or quantity, or the survival of infants, may decline with the age of the would-be father, the new study suggests. A new study from Washington University in St. Louis has implications for understanding some age-related aspects of male reproductive health in primates, including humans.