Chapter 6 Primate Behavior Key Terms

Social structure The composition, size, and sex ratio of a group of animals. Social structures, in part, are the result of natural selection in specific habitats, and they function to guide individual interactions and social relationships. Ecological Pertaining to the relationship between organisms and all aspects of their environment (temperature, predators, other animals, vegetation, availability of food and water, types of food, etc.).

Behavioral ecology The study of the evolution of behavior, emphasizing the role of ecological factors as agents of natural selection. Behaviors and behavioral patterns have been selected because they increase reproductive fitness in individuals in specific ecological contexts. Plasticity The capacity to change. In a physiological context, the ability of systems or organisms to make alterations in order to respond to differing conditions.

Socioecology The study of animals and all aspects of their habitats that attempts to identify relationships between components of the environment and behavior. Sociobiology The study of the relationship between natural selection and behavior. Unlike the approach of behavioral ecology, sociobiological theory does not strongly emphasize ecological factors.

Crepuscular Active during the evening or dawn. Dominance hierarchies Systems of social organization wherein individuals within a group are ranked relative to one another. Higher-ranking individuals have greater access to preferred food items and mating partners than lower-ranking individuals.

Communication Any act that conveys information, in the form of a message, to another individual. May be the result of involuntary processes or a secondary consequence of an intentional action. Autonomic Pertaining to physiological responses not under voluntary control. An example in humans is blushing. Convey information regarding emotional state, but is not a deliberate behavior, and communication is not intended.

Displays Sequences of repetitious behaviors that communicate emotional states. Nonhuman primate displays are most frequently associated with reproductive or agonistic behavior. Affiliative Pertaining to amicable associations between individuals. Affiliative behaviors, such as grooming, reinforce social bonds and promote group cohesion.

Territories Areas that will be aggressively protected against intrusion, particularly by other members of the same species. Home range The entire area exploited by an animal or group of animals.

Core area The portion of a home range containing the highest concentration of resources. Grooming Picking through fur to remove dirt, parasites, and other materials that may be present. Social grooming is common among primates and reinforces social relationships.

Altruism Any behavior or act that benefits another individual but poses some potential risk or cost to oneself. Reproductive strategies The complex of behavioral patterns that contributes to individual reproductive success. The behaviors need not be deliberate and often vary considerably between males and females.

K-selected Pertaining to an adaptive strategy whereby individuals produce relatively few offspring in whom they invest increased parental care. Although only a few infants are born, chances of survival are increased for each individual because of parental investments in time and energy. Examples of nonprimate K-selected species are birds and canids (e.g., wolves, coyotes, and dogs).

r-selected Pertaining to an adaptive strategy that emphasizes relatively large numbers of offspring and reduced parental care (compared to K-selected species). (K- selection and r-selection are relative terms; e.g., mice are r-selected compared to primates but K-selected compared to many fish species.)

Sexual selection A type of natural selection that operates on only one sex within a species. It is the result of competition for mates, and can lead to sexual dimorphism with regard to one or more traits. Polyandry A mating system wherein a female continuously associates with more than one male (usually two or three) with whom she mates. Among nonhuman primates, this pattern is seen only in marmosets and tamarins.

Anthropocentric Viewing nonhuman phenomena in terms of human experience and capabilities; emphasizing the importance of humans over everything else. Biological continuum The fact that organisms are related through common ancestry and that behaviors and traits seen in one species are also seen in others to varying degrees.