AR103- CH.7 Textbook Notes – Sept.25.12
Behavior: Anything organisms do that involves action in response to internal or external stimuli.
(May or may not be deliberate)
Ecological Perspective: relationships between organisms and their environment (temp.,
predators, food and water availability, vegetation, disease etc.)
Behavioral Ecology: study of evolution of behavior. Emphasizing the role of ecological factors as
agents of natural selection.
Behaviors have evolved through the operation of natural selection. Natural selection favors
characteristics that provide reproductive advantage.
Behavioral genetics: the study of how genes affect behavior.
Factors that influence social structure
BODY SIZE: Larger animals need less energy overall.
BASAL METABOLIC RATE (BMR): smaller animals have higher BMR than larger ones.
Smaller primates require energy-rich diet high in protein, facts, and carbohydrates. Larger
animals with slower BMR rates require less fatty foods such as leaves.
DISTRIBUTION OF RESOURCES: leaves are abundant and dense and can therefore feed larger
populations of animals. Insects scattered and can only be eaten by individuals. Fruits occur
scattered in groups in trees and shrubs, most efficiently exploited by small groups of animals.
PREDATION: Primates are vulnerable to a number of predators. (Snakes, birds, reptiles etc.)
Their responses to predators depend on type of predator and body size. When there is a
predator threat, and body size is small, large communities are better for defending.
DISPERSAL: individuals that disperse usually find mates outside their natal group. Reason for
dispersal: reduced comp. for mates, decreased likelihood of close inbreeding.
LIFE HISTORIES: characteristics or developmental stages that typify members of a species and
influence potential reproductive rates. EX: length of gestation, time between pregnancies,
period of infant dependency, weining age, sexual maturity age, life expectancy.
ACTIVITY PATTERNS: nocturnal primates forage for food alone or groups of 2 or 3 and hide to
avoid predators. HUMAN ACTIVITIES: human hunting and forest cleaning disrupt, isolate groups, reduce
numbers, reduce resource availability, and cause extinction.
Primate social behavior
DOMINANCE: certain degree of order by making parameters of individual behavior. Aggression
used to increase status, domin