Notes on Social Interactions in Primates

This lecture focuses on social interactions in primates, particularly in relation to reproductive strategies and behaviors.

Definition: Infanticide is identified as a male reproductive strategy.
When an outside male kills unweaned infants, mothers come into estrus sooner, increasing the male's mating opportunities.
Infanticide is observed across multiple species, including primates and birds, and is not considered aberrant behavior due to stress but a natural reproductive strategy.
Female Strategies Against Infanticide:
- Coalition: Females in female philopatric groups (group living with kin) band together to protect each other from infanticidal males.
- Friendships: In species like baboons, males may support females against threats and may even be the father of her offspring.
- Promiscuity in Chimpanzees: Female chimpanzees mate with multiple males to confuse paternity, potentially protecting their infants from infanticide.

Gorillas are typically safe from predation but still live in groups for reproductive safety, using dominant silverback males as protection against infanticide.
Females may move with stronger males who prove their toughness by killing infants, indicating reproductive fitness.

Monogamy vs. Polygamy:
- Monogamy: Having one mate.
- Polygamous: Multiple mates; includes polygyny (one male, multiple females) and rare polyandry (one female, multiple males).
- Mating systems adapt based on ecological factors, especially food distribution, influencing how males can monopolize females for reproductive success.