Chapter 5 - Male Strategies and Tactics

Abstract

This chapter looks at some of the reproductive strategies and tactics—both cooperative and competitive—that are found in males. Males tend to invest more of their reproductive effort into mating than into parenting; when possible, they will use a strategy that maximizes their number of matings and mating partners. Because “sperm is cheap,” some males can “afford” the energy it takes to find and court multiple females. In species in which females maintain a territory or for other reasons remain in one place, a male who traverses the greatest area is most likely to intercept the greatest number of females. As with humans, nonhuman courtship involves sending signals–first to attract attention, then to persuade. Since sexually dimorphic traits are related to testosterone production in males, the magnitude of a male's sexual signal is related in part to his level of testosterone production. Males are not so simple. Aggression and manipulation may be directed toward them just as it is toward other males. In many moths and butterflies, males have larger and more elaborate antennae. A female who is ready to mate will find a safe place to rest, then emit a chemical attractant (pheromone) to attract males; the male who reaches her first is likely to be the one to fertilize her eggs. Another selection pressure on males of short-lived species is for early maturation. The earlier a male matures, the fewer other males are out there to compete with. Unlike in humans in most animals, sex only occurs at or near the times that the female is fertile. The responses of females to males puts even further selection pressures in place, resulting in a complex, dynamic dialectic.