Chapter 50 Animal Behavior

Behavioral ecology Scientific study of behavior in natural environments from an evolutionary perspective Behavior What an animal does How it does it Usually in response to stimuli from the environment

Proximate causes of behavior Immediate causes that permit a specific behavior Genetic, developmental, and physiological processes Answer “how” questions

Ultimate causes of behavior Evolutionary explanations for behavior Answer “how” questions

Cost-benefit analysis to determine whether a behavior is adaptive Contribute to direct fitness Animal’s reproductive success measured by the number of viable offspring When benefits outweigh costs, behavior is adaptive

Behavior Results from the interaction of innate behavior and environmental factors Learned behavior Behavior is modified in response to environmental experience

Motor programs Coordinated sequences of muscle actions Walking is an example Fixed action pattern (FAP) Automatic behavior that, once activated, continues to completion regardless of feedback Can be triggered by sign stimulus

Egg-rolling behavior in the European graylag goose

Habituation Imprinting Type of learning in which an animal ignores a repeated, irrelevant stimulus Imprinting Establishes a parent-offspring bond Ensures that the offspring recognizes the parent

Imprinting

Classical conditioning An association is formed between some normal body function and a new stimulus Operant conditioning Learns a behavior by positive reinforcement or to avoid punishment

Classical conditioning

Operant conditioning

Insight learning Ability to adapt past experiences to solve a new problem Play May give young animals a chance to learn and practice adult behaviors

Insight learning

Biological rhythms Circadian rhythms are daily cycles Diurnal animals active in the day Nocturnal animals active at night Crepuscular animals active at dawn and/or dusk In mammals, the biological clock is located in the hypothalamus

Migration Periodic long-distance travel due to, for example, seasonal weather changes Directional orientation Travel in a specific direction, which requires compass sense Navigation requires both compass and map sense

Navigation by light and magnetic field

Optimal foraging The most efficient strategy for an animal to get food Often enhances reproductive success

Social behavior Adaptive interaction, usually among members of the same species Animal communication involves exchange of recognizable signals Pheromones are chemical signals that convey information between members of a species

Optimal foraging and group size in lions

Dominance hierarchy Ranking of status within a group More dominant members are accorded benefits, often without overt aggressive behavior

Communicating dominance

Home range Geographic area they seldom leave but do not necessarily defend Territory Defended area within a home range Costs include time, energy, and risk Benefits include rights to food and reduction in conflict among members

Home range

Society Group of individuals within the same species that may work together Insect societies tend to be rigid, narrowly defined, and with the division of labor determined by age Vertebrate societies are more flexible, with some species developing culture

Maintaining a complex social structure

Sexual selection Polygyny Polyandry Monogamy A male mates with many females Polyandry A female mates with several males Monogamy Mating with a single partner Pair bond is a stable relationship between a male and a female

Helping behavior Cooperative behavior includes reciprocal altruism In altruistic behavior, an individual behaves in a way that benefits others Inclusive fitness Number of offspring and offspring of kin Kin selection increases inclusive fitness through reproduction of close relatives