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

– Change in activity in response to stimulus

• Taxis– Automatic oriented

movement toward or away from a stimulus

• Migration

Animal Communication• Signal

– 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

– 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

– 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

– 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

– 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