Social Cooperation and Altruism

The capybara is a relatively simple species. Simple in the sense that capybaras need three basic thing s: water, foraging and resting areas. If the capybara is not eating, it is resting or wallowing.

So how does one characterize their behavior? First and foremost, capybara behavior, as a whole, can be labeled as cooperative; behavior varies between different groups but in all cases, it is cooperative.

Males exhibit cooperative behavior with each other. The dominant male is responsible for defending his territory and allows subordinate males to stay with the group because they offer four or six more vigilant eyes to the social group. Subordinate males, although marginalized to the outside of the group, garner many benefits like the protection only attained through group living, grazing areas and access to females (whenever they can sneak past the dominant male.) The relationship between the dominant male and the females is also cooperative; both the recipient and the actor's fitness are increased in this relationship. The dominant male has access to all of the females and in return provides protection and access to water, grazing and resting areas.

Females in the group are usually sisters or they are from the same weaning group. Females exhibit cooperative behavior also. Part of altruism involves decreasing one's own fitness in order to increase the fitness of another. Female capybaras, in general, do not place themselves in positions of vulnerability to benefit another sister. Female capybaras present cooperative behavior because they take turns taking care of the young. They all have a vested interest in the survival of their offspring. This is not always the case. The presence of infanticide (some capybaras non-maliciously kill their offspring when removing the placenta after birth) is indicative of selfish behavior. Infanticide is rare and provides the only exception to the cooperative nature of the female. A possible expla nation for infanticide is the introduction of an outside female to the group later in life. This female is not related to the other females and tries to increase her own fitness by decreasing her "competition."

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