ap biology behavioral ecology
Post on 16-Feb-2017
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Behavioral Ecology
MOSTLY VOCAB – listen to concepts/stories to explain each
term
Behavioral ecologyThe study of how animal behavior develops, evolves, and contributes to survival and reproductive success
Ethology - a narrower field that just studies behavior, without all the ecological parts
We ask 2 kinds of questions
1. Proximate questions - ask about the environmental stimuli that trigger a behavior (“how” questions)
e.g. “How does the length of daylight affect breeding behavior in cranes?”
2. Ultimate questions - ask about the evolutionary significance of a behavior (“why” questions)
e.g. “Why did natural selection favor this behavior and not a different one?”
Animal Behaviors1. Fixed Action
Patterns (FAP)Unlearned behaviorsUsually unchangeableInnate (genetic, born able to do it)Triggered by an external stimulusCarried to completion once initiated
Story of the sticklebacks
Animal Behaviors2. Imprinting
Includes both learning and innate componentsUsually irreversibleComes about during a sensitive period during development when the behavior MUST be learned
The story of ducks, geese, cranes
Caution
All behaviors have some genetic and some environmental componentThe question is not “Nature or Nurture”The question is “How do both nature and nurture affect behavior?”
Animal Behaviors w/ strong genetic basis
Kinesis A change in activity in response to a stimulus; a change in speed – move faster in unfavorable environments and slower in favorable ones. The net result is more time in favorable placesNot directed
The story of the isopods
Animal Behaviors w/ strong genetic basis
TaxisAn automatic, reflex oriented movement toward (positive taxis) or away from (negative taxis) something, like moths to the light
The story of the fish
Animal Behaviors w/ strong genetic basis Migration
Strong genetic component
Story of the black caps
Some populations migrate; some do notIn migrating populations, caged birds show restlessness during migration time
Animal Communication is strongly genetic
Use visual, auditory, chemical, tactile, and electrical signals to communicate
Pheromones - chemical signal that affects behaviorBird songs are at least partly learnedInsect songs are almost purely genetic
Animal Behaviors w/ a strong environmental basis
Environmental factors like:Quality of dietSocial interactionsLearning opportunities
A coyote with a face full of porcupine quills - ouch!
Animal behaviors with a strong environmental basisLearning - the modification of behavior based on specific experiences
ImprintingHabituationSpatial learningCognitive mapsAssociative learningCognition and
problem solving Chimps teaching each other how to hammer open palm nuts
HabituationLoss of responsiveness to stimuli
Venus flytrap closes when triggered, unless it keeps getting touched without the reward of foodBaby ducks run for cover when something flies overhead, unless it keeps happening and no one gets attackedResearchers often have to habituate their study population to their presence
Spatial Learning
The modification of behavior based on experience with the spatial structure of the environment
Where the good nesting sites are, where food can be found, what areas to avoid Wasps use landmarks to
locate nests
Cognitive Maps
An internal representation of the spatial relationships in an animal’s environment
Ravens and jays store food in cachesMay store 1000s of nuts in 1000s of different placesThey can remember where food is stored and even what kind of food is stored in each place using landmarks as identifiers
Associative learningThe ability to associate one feature of the environment with another
Classical conditioning - an arbitrary stimulus is associated with reward or punishment - Pavlov’s dogsOperant conditioning - an animal learns to associate its own behavior with reward or punishment
Cognition & problem solvingThe ability of an animal to perceive and process information
Some animals have very advanced problem solving skills
PrimatesDolphinsMany birds like crows, ravens, and jaysOctopi
Animals can learn from each other
Natural selection can result in the evolution of behaviors
Best evidence for this is variations in behaviors between and within species
Example:Different populations of garter snakes prey on different animals
Natural selection favors individuals who can capitalize on the dominant food source
Optimal Foraging TheoryForaging is a compromise between the benefits of getting food and the energy spent getting it or the risk of getting eaten by a predator while trying to get foodNatural selection favors those that maximize the benefits and minimize the costs
Optimal height drop is 5 m - least amount of work for most benefit…most birds drop frfom exactly this height
Mating BehaviorsMay be
Promiscuous - no lasting relationshipsMonogomous - 1 male w/ 1 female
Both sexes often look alikeMany birds are this way because the young require so much care they need 2 parents
Polygymous - one individual mating w/ several others
Polygyny - 1 male, several females - more common
Female mammals care for young by nursing - don’t need dad to help so he maximizes his reproductive success by mating with severalMales often “prettier” in this type
Polyandry - 1 female, several males
Mating BehaviorsCertainty of paternity an issue
Of course the kids are the mom’s, but are they the dad’s?With internal fertilization, behaviors like guarding females or releasing large amounts of sperm occur to help ensure paternityWith external fertilization, paternity is pretty much a given, so males may help with care of the young more
Male jawfish cares for young…external fertilization guarantees they are his
Bull male protects his harem of females from other males
Mating BehaviorsFemale choice has led to the natural selection of particular traits in males
Social Behavior & Altruism
Altruism - selfless behavior for the benefit of othersBenefits the passing of genes - which is what “success” is all about in biology
One queen is cared for by all others…they even die to save her
Altruism and relatedness
Coefficient of relatedness – a statistic that represents the average number of genes 2 individuals shareThe more they share, the more likely they will help each otherSiblings share 50% of their genes
Agnostic Behavior
Conflict behavior over a resource; usually just big displays of strength
Dominance Hierarchies
Ranking among members of a group; subject to change; reduces conflict among members since everyone knows their place
Territoriality
Defense of territory to keep others out
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