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ANIMAL BEHAVIOR. CAMPBELL & REECE CHAPTER 51. ANIMAL BEHAVIOR. a behavior is an action carried out by muscles under control of the nervous system in response to a stimulus. Behavior. over time is subject to natural selection u nderstanding any behavior requires answering 4 ?s
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ANIMAL BEHAVIOR CAMPBELL & REECE CHAPTER 51
ANIMAL BEHAVIOR • a behavior is an action carried out by muscles under control of the nervous system in response to a stimulus
Behavior • over time is subject to natural selection • understanding any behavior requires answering 4 ?s • What stimulus elicits the behavior, & what physiological mechanisms mediate the response? • How does the animal’s experience during growth & development influence the response? • How does the behavior aid survival & reproduction? • What is the behavior’s evolutionary history?
Behavioral Ecology • study of the ecological & evolutionary basis for animal behavior
Fixed Action Patterns • sequence of unlearned acts directly linked to a simple stimulus • are essentially unchangeable • once started, they continue to completion • sign stimulus: the trigger for the behavior
Migration • a regular long-distance change in location • animals use environmental stimuli to provide cues to trigger behavior • some animals track their position relative to the Sun (even though Sun’s position relative to Earth changes thru out the day)
Migration • animals adjust to changes in Sun’s or stars position by means of circadian clock • some use magnetic fields (pigeons & some fishes)
Behavioral Rhythms • linked to seasons called: circannual rhythms • influenced by periods of daylight & darkness in the environment • birds exposed to artificial light simulating longer daylight hrs will start to migrate
Behavioral Rhythms • not all are linked to light/dark • male fiddler crab waves large claw to attract mates using signal of full or new moon
Animal Signals & Communication • a stimulus transmitted from 1 animal to another is called a signal • transmission & reception of signals constitutes animal communication
Forms of Animal Communication • 4 common modes of animal communication: • Visual • Chemical • Tactile • Auditory
Forms of Animal Communication • courtship behavior of Drosophila melanogaster • is a stimulus-response chain (response to each stimulus is the stimulus for next behavior
Pheromones • chemical substances released by animals that communicate thru odors or tastes • common among mammals & insects • often related to reproductive behavior
Pheromones as Alarm Signals • in fish: if 1 injured injured cells release substance that increases vigilance of other fish school becomes more tightly packed move to lake or river bottom where they are safer
Innate Behavior • animal behavior that is developmentally fixed & under strong genetic control • it is exhibited in virtually same form in all individuals in a population despite internal & external environmental differences during development & thru out their lifetimes
Experience & Behavior • How do researchers test the 2nd ?: • How an animal’s experience during growth & development influence the response to stimuli?
Cross-Fostering Study • young of 1 species placed under the care of adults from another species • these studies can be used to measure the influence of social environment & experience on behavior
Human Twin Studies • compare behaviors of identical twins raised apart with those raised in same household • studies have revealed nature & nuture both contribute significantly
Learning • modification of behavior based on specific experiences
Imprinting • formation at a specific stage in life of a long-lasting behavioral response to a specific individual or object • distinguished from other types of learning by having a sensitive period or critical period: a limited developmental phase when this type of learning can occur
Imprinting • during the sensitive period: • the young imprint on their parent & learn basic behaviors of their species • parents learn to recognize their offspring
Imprinting • birds have no innate recognition of “mother” • they identify with the 1st object they encounter that has certain key characteristics (like any object that is moving away from them)
Spatial Learning • establishment of a memory that reflects the environment’s spatial structure • studied digger wasps: • Mother covers entrance with sand when leaves nest..always comes right back to it • hypothesized she locates her nest by learning its position relative to local landmarks
Cognitive Map • some animals guide their activity using a cognitive map: a representation in the nervous system of the spatial relationships between objects in an animal’s surroundings • these animals can navigate more flexibly & efficiently by relating landmark positions to one another
Associative Learning • ability to associate 1 environmental feature (like color) with another (foul taste)
Associative Learning • suited to lab studies because usually involves classical conditioning or operant conditioning
Classical Conditioning • an arbitrary stimulus becomes associated with a particular outcome
Operant Conditioning • aka “trial-and –error” learning • animal learns to associate one of its behaviors with a reward or punishment & then tends to repeat or avoid that behavior
Associative Learning & Evolution • makes sense that some animals cannot learn to make particular connections… • associations animals make typically reflect relationships likely to occur in nature • associations that cannot be formed are those unlikely to be of selective advantage in a native environment
Cognition • process of knowing that involves: • awareness • reasoning • recollection • judgement
Cognition • has been thought that only humans, higher apes & marine mammals • but...some insects & many other groups of animals have demonstrated some levels of cognition in lab experiments
Problem Solving • the cognitive activity of devising a method to proceed from 1 state to another in the face of real or apparent obstacles • varies with individual experience & abilities
Development of Learned Behaviors • some birds learn their songs in stages (during a sensitive period) • young sparrow does not sing but memorizes adult songs • followed by a 2nd learning phase when juvenile bird sings tentative notes called a subsong • juvenile bird compares his subsong to adult song..when he has it right the song “crystallizes”…bird will only sing that song rest of life
Social Learning • modification of behavior thru observation of other individuals • young chimps learn to crack nuts by watching their elders • young vervet monkeys learn correct use of alarm calls by (+) reinforcement from elders
Social Learning • forms the roots of culture (a system of information transfer thru social learning or teaching that influences the behavior of individuals in a population) • can change behavior and thereby influence the fitness of individuals
Foraging Behavior • food-obtaining behavior • an optimal foraging model is based on the idea that natural selection should favor the foraging behavior that minimizes the costs of foraging & maximizes the benefits
Mating Behavior & Mate Choice • mating behavior & mate choice play a major role in determining reproductive success • includes: • seeking or attracting mates • choosing among potential mates • competing for mates • caring for offspring
Mating Systems • vary with regard to both the length & # of relationships • Promiscuous: no strong pair-bonds • Monogamous: mates remain together for longer periods of time • Polygamous: an individual of one sex mating with several of the opposite sex