AP Biology

Behavioral Ecology

meerkats

AP Biology

Why study behavior? Evolutionary perspective…

part of phenotype acted upon by natural selection

lead to greater fitness? lead to greater survival? lead to greater reproductive success?

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What questions can we ask? Proximate causes

immediate stimulus & mechanism “how” & “what” questions

Ultimate causes evolutionary significance how does behavior

contribute to survival & reproduction adaptive value

“why” questions

male songbird what triggers singing?

how does he sing? why does he sing?

male songbird what triggers singing?

how does he sing? why does he sing?

how does daylength influence breeding? why do cranes breed in spring?

how does daylength influence breeding? why do cranes breed in spring?

Courtship behavior in cranes what…how… & why questions

Courtship behavior in cranes what…how… & why questions

AP Biology

What is behavior? Behavior

everything an animal does & how it does it response to stimuli in its environment Nervous to muscular system involvement

innate behaviors automatic, fixed, “built-in”, no “learning curve” despite different environments,

all individuals exhibit the behavior learned behaviors

modified by experience variable, changeable flexible with changing environment

AP Biologyattack on red belly stimulus

court on swollen belly stimulus

Innate behaviors Fixed action patterns (FAP)

Sequence of unlearned acts that are triggered by a sign stimulus (external cue) Carried out to completion

male sticklebacks exhibit aggressive territoriality

Egg Laying Geese

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Complex Innate behaviors Use of environmental cues to carry out behavior

Migration, Hibernation, Estivation, Courtship “migratory restlessness” seen in birds bred & raised in captivity navigate by sun, stars, Earth magnetic fields

Monarchmigration

Sandpiper

ancient fly-ways

Bobolink Golden plover

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Innate: Directed movements Taxis

Response movement toward (positive taxis) or away from (negative taxis) a stimulus phototaxis chemotaxis

Kinesis Random movement in

response to a stimulusex: stopping, starting, or

turning.

ex: sowbug “kinesis”

increases when conditions

are dry.

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Plant Behaviors Responses to environment Governed by hormonal signals Phototaxis – movement towards light Photoperiodism – response to different

times of day

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Learning: Imprinting Young animals go through a “critical

period” whereafter they follow the organisms present during the period.

Konrad Lorenz

video

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Learning: Associative learning to associate

a stimulus with a consequence operant conditioning

trial & error learning associate behavior with

reward or punishment ex: learning what to eat

classical conditioning Pavlovian conditioning associate a “neutral

stimulus” with a “significant stimulus”

Frazier

Sheldon

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Learning: HabituationLoss of response to stimulus

decrease in response to repeated occurrences of stimulus

enables animals to disregard unimportant stimuli ex: falling leaves not triggering fear

response in baby birds ex: animals standing next to

highway don’t get frightened after time

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Learning: Spatial Establishment of

memories that reflect the physical structure of the environment.

Ex: Squirrels using physical markers to find buried food.

Ex: Wasps using physical markers to find their nest.

AP Biologysea otter

Learning: Problem-solving/Cognition Involves reasoning, awareness,

recollection and judgment

tool use

crow

Insight learning

Griffin

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Social behaviors Interactions between individuals that develop

into evolutionary adaptations communication / language agonistic behaviors dominance hierarchy cooperation altruistic behavior

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Visual Communication Honey bees

dance to communicate location of food source

waggle dance

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Sound Communication Bird song

species identification & mating ritual mixed learned & innate critical learning period

Insect song mating ritual & song innate, genetically

controlled

Red-winged blackbird

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Chemical Communication

Pheromones chemical signal that stimulates an

innate response from other individuals alarm pheromones sex pheromones

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Pheromones

Spider using moth sex pheromones, as allomones, to lure its prey

The female lion lures male by spreading sex pheromones, but also by posture & movements

Female mosquitos use CO2 concentrations to locate victims……but apparently some of us breathe more than others…

marking territory

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Social behaviors Agonistic behaviors

threatening & submissive rituals symbolic, usually no harm done

ex: territoriality, competitor aggression

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Social behaviors Dominance hierarchy

social ranking within a group “pecking order”

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Social behaviors

Pack of African dogs hunting wildebeest

cooperatively

White pelicans “herding” school of fish

Cooperation working together in coordination

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Behaviors should increase fitness! Foraging behavior:

Finding food and the energy costs Mating systems:

monogamy – single parents don’t work well, so males and females raise offspring together

polygamy/polyandry – maximizing reproductive success and protection

Certainty of paternity: Behaviors to increase chance of sperm fertilization

Sexual Selection/Mate Choice: Sexual dimorphism results Courtship behaviors – correlate to general health

Birds

Moonwalker

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Social behaviors Altruistic behavior

reduces individual fitness but increases fitness of recipient increasing survival of close relatives passes family genes

on to the next generation – evolutionary fitness!

How can this be of adaptive value? Belding ground squirrel

“Kin Selection”

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“Picture a hot dog that's been left in a microwave a little too long…add some buck teeth at one end, and you've got a fairly good idea of what a Naked Mole Rat looks like.”

Colonial mammals are altruistic! Naked mole rats

underground colony, tunnels queen, breeding males, non-breeding workers hairless, blind

AP Biology

Make sure you can… Provide proximate and ultimate

explanations for behaviors Compare innate and learned behaviors and

provide examples of each Describe how a particular behavior can

evolve Explain how particular behaviors contribute

to an organism’s fitness Explain how altruistic behaviors can evolve

in a population

AP Biology 2008-2009

Any Questions??