Chapter 51: Behavioral Ecology

1. Chapter 51: Behavioral Ecology Behavioral ecology How behavior develops, evolves, & contributes to survival & reproductive success Ethology Study of animal behavior (in the animal’s natural environment) Behavior What an animal does & how the animal does it Cause of behavior Proximate Environmental trigger for behavior as well as genetic, physiological, & anatomical mechanism for the act “how” Ultimate Addresses evolutionary significance for behavior “why”

2. Types of behavior • Instinct • Inherited behavior; developmentally fixed • Examples: • Directional movements • Kinesis- change in activity or rate in response to a stimulus (ex. sow bugs more active in humidity) • Taxis- oriented movement toward or away from a stimulus (ex. Trout face current) • Migration (ex. Migratory restlessness in blackcap birds) • Animal Signals & Communications • Signal=behavior that causes a change in another animal’s behavior • Communication= transmission of, reception of, & response to signals • visual • Tactile • electrical signals

3. Chemical • Releaser Pheromones- cause immediate behavior change • Primer pheromones- cause physiological change • Auditory • which communication is used is dependant on animal’s environment & lifestyle • Fixed Action Patterns • Sequence of unlearned, unchangeable behavioral acts carried out to completion once initiated • Triggered by sign stimulus (external sensory stimuli) • Ex. Male stickleback fish aggressively defends territory when triggered by red color

4. Imprinting • Behavior that involves learning & innate components & is irreversible • Sensitive period: Brief period in which behavior can be learned (typically from parent) • Ex. Graylag gosling accept any moving object as mother during 1st 2 days • Learning • Modification of behavior based on specific experiences • Habituation • loss of responsiveness to stimuli that convey little or no information • “cry-wolf” effect

5. Spatial Learning • Modification of behavior based on experience with spatial structure in the environment (location of nest, hazards, food, mates) • Use landmarks as location indicators • Cognitive maps • Internal representation/code of the spatial relationships between objects in an animal’s surroundings • Associate learning • Ability to associate one feature of the environment (stimulus) with another (the response it produced) • Classical conditioning- stimulus is associated with a reward or punishment • Operant conditioning/trial & error learning- animal associates one of its own behaviors with reward or punishment • Cognition & problem solving • Ability of an animal’s nervous system to perceive, store, process, & use information gathered by sensory receptors

6. **Natural Selection can act on behavior that has a genetic component • Behavioral Variation can exist in • prey selection • aggressive behavior • Parental care • Migratory patterns • **Natural selection most often acts on behaviors that increase survival & reproductive fitness…. • Foraging behavior • Mating behavior & choice

7. Foraging Behavior • Optimal foraging theory • food obtaining behavior is a compromise between the benefits of nutrition & the cost of obtaining food • Costs include- energy expenditure, risk of own predation • Examples: • Northwestern crows flying up to break open shells of molluscs • Bluegill sunfish selecting larger vs. smaller crustaceans • Mule deer feeding in open areas vs. forest edges • Mating Behavior & Mate choice • Mating relationships • Promiscuous- no pair bonds • Monogamous- single pair bond; no dimorphism • Polygamous- sexual dimorphism • Polygyny- one male mating with several females; male ornamented • Polyandry- single female mating with several males; female ornamented • Need for parental care & certainty of paternity influence mating behavior

8. Sexual selection & mate choice • Intersexual selection • Female preference for a male mating behavior or anatomy influences that behavior or anatomical structure’s rate of occurrence • Female prefer traits that signal male quality/health • Intrasexual selection • Male competition for mates • Agnostic behavior- ritualized contest that determines which male gains access to the resource • Game Theory- • Different strategies effectiveness may vary based on environment & strategies of other individuals • Ex. Ispod Paracerceis sculpta alpha, beta, & gamma males; orange, yellow, & blue throat lizards

9. Social Behavior & altruism • “Selfish” behavior can be explained by natural selection • Altruism: selflessness; animal behaves in such a way that decreases its own fitness but increases the fitness of others in the population • Examples: • Belding’s ground squirrel’s alarm call • Worker bee sterility; sting & die • Naked mole rats protecting queen & kings • Inclusive fitness: total effect an individual has on proliferating its genes through its own offspring or through a relatives offspring • rB>C favors altruistic behavior where: • r= coefficient of relatedness • B= benefit to the altruistic behavior (average # offspring that will be produced as a result) • C= cost of altruistic behavior (average # of offspring that will not be produced as a result)

10. Kin selection • Individual acts to enhance the reproductive success of relatives • improves the chance that genes the same as his/her own are passed on • Reciprocal altruism • Altruistic individual aids a non-relative with “hope” that the favor will be returned in the future • Found most often in highly social species in which “cheating” would lead to negative consequences • “tit for tat” • Social Learning • Learning through observing others • Culture: system of information transfer through social learning or teaching of individuals in a population • Example: Vervet monkey alarm calls • Sociobiology: study of human culture & its relationship to evolutionary biology