Behavior- anything organisms do that involves action in response to internal or external stimuli; the response of an individual, group, or species to its environment. Such responses may or may not be deliberate, and they aren’t necessarily the results of conscious decision making. Ecological- pertaining to the relationships between organisms and all aspects of their environment 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 favored because they increase the reproductive fitness of individuals in specific environmental contexts. Plasticity- the capacity for change. In a behavioral context, the ability of animals to modify actions in response to differing circumstances. Social structure- the composition, size, and sex ratio of a group of animals. Social structures are partly the results of natural selection in specific habitats, and they guide individual interactions and social relationships. Metabolism- the chemical processes within cells that break down nutrients and release energy for the body to use. Some Factors that Influence Social Structure: - Body size -Basal metabolic rate (BML) and diet -Distribution of resources -Predation -Relationships with other, non-predatory species -Dispersal -Life histories -Distribution and types of sleeping sites -Activity patterns -Human Activities Life history traits- also called life history strategies; characteristics and developmental stages that influence rates of reproduction Social Behavior Dominance hierarchies- systems of social organization in which individuals within a social group are ranked relative to one another. Higher-ranked animals have greater access to preferred food items and mating partners than do lower-ranking individuals. Dominance hierarchies are sometimes called pecking orders. Communication- any act that conveys information, in the form of a message, to another individual. Frequently, the result of communication is a change in the recipient’s behavior. Communication may not be deliberate, but may instead 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 chimpanzees would be the erection of body hair during excitement. Blushing is a human example. Both responses convey information about emotional states, but neither is deliberate and communication isn’t intended. Displays- sequences of repetitious behaviors that serve to communicate emotional states. Nonhuman primate displays are most frequently associated with reproductive or aggressive behavior. Affiliative- pertaining to amicable associations between individuals. Affiliative behaviors, such as grooming, reinforce social bonds and promote group cohesion. Territories- portions of an an individual’s or group’s home range that are actively defended against intrusion, especially by members of the same species. Core area- the portion of a home range containing the highest concentration and most reliable supplies of food and water. The core area is usually defended. Grooming- picking through fur to remove dirt, parasites, and other materials. Social grooming is common among primates and reinforces social relationships. Altruism- behavior that benefits another individual but at some potential risk or cost to oneself. Reproduction Reproductive strategies- the complex of behavioral patterns that contributes top individual reproductive success. The behaviors need not be deliberate, and they 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 paternal care. Although only a few infants are born, chances of survival are increased for each one because of paternal investments in time and energy. Examples of K-selected non-primate species are birds and canids. R-selected- an adaptive strategy that emphasizes relatively large numbers of offspring and reduced paternal care (compared to K-selected species). K-selection and r-selection are relative terms, for example, mice are r-selected compared to primates but K-selected compared to fish. Sexual selection- a type of natural selection that operates on only one sex within a species. It’s the result of competition for mates, and it can lead to sexual dimorphism with regard to one or more traits. Polygynous- referring to polygyny, a mating system whereby males have more than one mate. Polyandry- a mating system wherein a female continuously associates with more than one male with whom she mates. Among nonhuman primates, polyandry is seen only in marmosets and tamarins. It also occurs in a few human societies. Biological continuum- refers to 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.