Introduction

Infants have the strongest incentive to avoid infanticide. Paradoxically, they are the least capable of preventing it. Primate infants are particularly vulnerable because they take a long time to develop the physical and cognitive capacity to avoid risk. Yet infants are not utterly helpless in the face of infanticidal threats. Through detection, avoidance and deterrence, infants and their caregivers prevent infanticide. If infanticide is treated as a series of steps preceding lethal injury, one can see several junctures at which animals can act to lower risk (Figure 10.1). Protectors can prevent infanticide at every step. Neonate self-protection is generally limited to the earliest steps in the process. An older infant may have more options.

In this chapter, I explore the behaviors used by primates to prevent infanticide. I begin with protectors and then turn to infant self-protection. In both sections, I search for evidence of specific adaptations to infanticide prevention. The final section specifically addresses infant transport and the coevolution of primate mothers and infants.

Protectors

Primate infants are cared for by a variety of individuals: mothers, fathers, older siblings, more distant kin, as well as some unrelated adults (Hrdy 1976; Nicolson 1987; Whitten 1987; Manson 1999; Paul 1999). Within groups, the sexes usually take different roles in infant protection. A common pattern is for females to perform direct care (e.g., transport, feeding) while males provide indirect care (e.g., guarding).