ABSTRACT

The evolution and proximate causation of paternal behavior in mammals poses an interesting theoretical problem. Males normally maximize reproductive success by mating with multiple females, whereas female reproductive success is ordinarily limited by time and energy constraints (Williams, 1966; Trivers, 1972). Females are likely to benefit from increased male parental assistance (Wittenberger and Tilson, 1980), but any male investment in one female's young necessarily reduces the male's chances of inseminating other females, which would appear to create an insurmountable evolutionary barrier to male parental care (Kurland and Gaulin, 1984).