Behavioral Ecology
Behavior Ethology- study of animal behavior Causation: Proximate- physiological & genetic mechanisms of behavior “how” Ultimate- evolutionary significance of behavior “why” Sign stimulus- external sensory stimulus Fixed action pattern (FAP)- sequence of acts; unchangeable; carried to completion Ex: 3-spined stickleback Aggressive behavior triggered by red underside No response response
Imprinting Both learning and innate components Must be acquired during a certain limited phase of an organism’s development Geese imprint and follow “mother” Must occur within 1-2 days
Innate Behavior Strong genetic influence Kinesis Taxis Migration Change in activity in response to stimulus Taxis Automatic oriented movement toward or away from a stimulus Migration
Animal Communication Signal Communication Behavior that causes a change in another animal’s behavior Communication Chemical (pheromones) Auditory (songs, calls)
Learning Maturation- behavior due to developing physiological changes Habituation- loss of responsiveness to stimuli that convey no information; simple learning Spatial learning- use “landmarks” as location indicators Cognitive mapping- internal representation of spatial relationships/locations Associative learning: Classical conditioning- Pavlov’s dogs Operant conditioning (trial and error)- “Skinner’s box”
Behavioral Evolution Behaviors are genetically based, so they can undergo natural selection Organisms from different populations exhibit different behaviors Prey selection Aggression Foraging Migration
Foraging Behavior Optimal Foraging Theory Compromise between benefits and cost of obtaining food Energy cost Risk of predation
Social Behavior Sociobiology Agonistic behavior Dominance hierarchy evolutionary theory applied to social behavior Agonistic behavior contest behavior determining access to resources Dominance hierarchy linear “pecking order” Territoriality an area an individual defends excluding others
Mating Systems Promiscuous Monogamous Polygamous Polygyny Polyandry no strong pair bonds Monogamous one male/one female Polygamous one with many Polygyny one male/many females Polyandry one female/many males
Sexual Selection Mate choice Competition between males Female mate selection Influenced by imprinting (traits seen in parents) Competition between males Aggression/ antagonistic behavior Game theory- individuals use different strategies to obtain success
Altruistic behavior Inclusive fitness Coefficient of relatedness total effect an individual has on proliferating its genes by its own offspring and aid to close relatives Coefficient of relatedness proportion of genes that are identical because of common ancestors Kin selection aiding related individuals altruistically (selflessly) Reciprocal altruism exchange of aid