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Behavioral Adaptations to the Environment. Ch. 35. Goals. Define and distinguish between the proximate and ultimate causes of behavior. Describe the adaptive advantage of innate behaviors. Describe the respective roles of genetics and the environment in shaping behavior.
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Goals • Define and distinguish between the proximate and ultimate causes of behavior. • Describe the adaptive advantage of innate behaviors. • Describe the respective roles of genetics and the environment in shaping behavior. • Define the six types of learning discussed in lecture. • Define search images and optimal foraging. • Explain how courtship rituals are adaptive. • Compare monogamous and polygamous • Define social behavior and sociobiology
Goals 9. Define a territory and describe the ways in which territories are used, identified, and defended. 10. Define agonistic behavior and explain how agonistic behavior is adaptive. • Explain how dominance hierarchies are maintained and identify their adaptive value.
Behavioral Ecology • the study of behavior in an evolutionary context. • Behavior: an animal’s responses to internal and external environmental cues.
Behavioral Ecology Questions • 2 types 1.Proximate questions concern the immediate reason for the behavior. • How is it triggered by stimuli (environmental cues that cause a response)? • What physiological or anatomical mechanisms play a role? • What underlying genetic factors are at work? • Proximate causes are the answers to such questions about the immediate mechanism for behavior. 2.Ultimate questions address why a particular behavior occurs. Ultimate causes are the evolutionary explanations for behavior.
Ex. Proximate & Ultimate Causation • Proximate Cause: simple reflex • Ultimate Cause: Natural Selection for behavior that minimizes damage
Innate Behavior • under strong genetic control • are performed in virtually the same way by all individuals of a species • Inflexible • “built-in” • Ex. Birds hatching from eggs • Not breathing under water
Fixed Action Patterns (FAPs) • an unchangeable series of actions • triggered by a specific stimulus. • Once initiated, the sequence is performed in its entirety, regardless of any changes in circumstances.
Figure 35.2A Egg Retrieval FAP
Genetics & Environment • Animal behavior often involves a combination of genetic programming and environmental factors • Fruit Flies • learning and memory, • internal clocks, • courtship, and • mating behaviors.
Figure 35.3 High-interaction mother Low-interaction mother Pups become relaxed adults Pups become fearful adults Female pups becomehigh-interaction mothers Female pups becomelow-interaction mothers Cross-fosteringexperiment Pups become relaxed adults Pups become fearful adults
Learning • modification of behavior as a result of specific experiences. • Learning enables animals to change their behaviors in response to changing environmental conditions. • There are various forms of learning • a simple behavioral change in response to a single stimulus • complex problem solving using entirely new behaviors
Habituation • Simple type of learning • Loss of response to a stimulus after repeated exposure • animal learns not to respond to a repeated stimulus that conveys little or no information • In terms of ultimate causation, habituation may increase fitness by allowing an animal’s nervous system to focus on stimuli that signal • food, • mates, or • real danger. • Think: the boy who cried wolf
Imprinting • Irreversible learning • limited to a specific phase in an animal’s life called a sensitive period. • Ex. • a young bird learning to identify its parents • song development in birds • “Baby Duck Syndrome” (humans & computers)
Spatial Learning • Movement can be a reaction or a product of learning • Kinesis is a random movement in response to a stimulus • Taxis is a response directed • toward (positive taxis) or • away from (negative taxis) a stimulus
Spatial Learning Cont’d • animals establish memories of landmarks in their environment that indicate the locations of • food, • nest sites, • prospective mates, and/or • potential hazards • Movement guided by learning landmarks
Associative Learning • Associate one environmental feature with another • MEMORY • Link a stimulus to an outcome • Ex. Dogs associate lease with walks • Trial & Error: associate a behavior with an outcome Forming Connections
Social Learning • learning by observing the behavior of others. • Ex. Many predators learn some of their basic hunting tactics by observing and imitating their mothers.
Problem Solving Learning • Ability to apply past experiences to new situations • Cognition: the ability of an animal’s nervous system to perceive, store, integrate, and use information gathered by the senses. • Problem-solving behavior • is highly developed in some mammals, especially dolphins and primates, and • has been observed in some bird species.
Foraging Studies • Behavioral Ecologist study how animal forage • Generalists, specialists, etc. • Search Image: mechanisms animals use to find specific food sources
Cost v. Benefit • Trade-offs involved in food selection • The amount of energy may vary considerably in • locating • capturing • preparing prey for consumption • Optimal foraging theory predicts that an animal’s feeding behavior should provide • maximal energy gain with minimal energy expense an • minimal risk of being eaten while foraging.
Communication • Behavioral ecologist study communication between organisms • Interactions dependent upon communication • Animal communication includes • Sending signals • Receiving signals • responding to signals • Forms of communication vary considerably • Ex. Nocturnal (odor & sound) • Ex. Honeybee dances • Communication essential for mating
Mating • Courting Rituals: elaborate communication • Confirms that: • individuals are of the same species, • of the opposite sex, • physically primed for mating • not threats to each other.
Mating Systems • Connected to reproductive & child rearing success 1. Promiscuous systems • No strong pair-bonds • Fleeting relationships between males and females. 2. Monogamous systems • one male and one female • both parents participating in parental care • Rare 3.Polygamous systems • have one individual of one sex mating with several of the other • usually consist of one male and many females.
Offspring Viability & Mating System • Needs of offspring & certainty of paternity shape mating system & paternal care by males • Cost v. Benefit relationship • Ex. Birds and Monogamy • Ex. Pheasants & Polygamy
Cost v. Benefits Costs of Parental Care Benefits Females Almost certain success (pass on genes) Males Paternity is never certain Mating & birth separated by time in many cases Harems up odds • Energy • Loss of mating opportunities
Sociobiology (Social Behavior) • Applies evolutionary theory to the study and interpretation of social behavior to explain how social behaviors • are adaptive and • could have evolved by natural selection • Social behavior: any kind of interaction between two or more animals
Territorial Behavior • Territory is an area, usually fixed in location, • which individuals defend • other members of the same species are usually excluded. • Territories are usually used for • feeding, • mating, • rearing young • How are territorial behaviors beneficial?
Agonistic Behavior • Conflicts over resources settled by agonistic behaviors • threats, rituals, and sometimes combat that determines which competitor gains access to a resource • can directly affect an individual’s evolutionary fitness • Ritualization favored
Dominance Hierarchies • Ranking of individuals based on social interactions. • Ex • pecking order in chickens • females within a wolf pack • Established & Maintained with agonistic behaviors
Human Behavior • Genes & Environment • Twin studies suggest 50% of complex behavior has a genetic factor • Genes do not dictate behavior but, instead, cause tendencies to react to the environment in a certain way. • The mechanisms and underlying genetics of behavior are proximate causes. • Sociobiologists explore the ultimate causes of human behavior.