Transcript

Review and Animal Behavior

Animal behavior

Examples? Definition Why study behavior?

How to study animal behavior Ethology: The study of animal behavior

in its natural environment Mid 20th century Tinbergen, von Frisch, Lorenz 4 foundational questions

Mechanistic basis of the behavior How does development influence behavior Evolutionary history of the behavior How does the behavior contribute to its

fitness? Behavioral ecology: Stems from

ethology, and attempts to explain how animal behaviors are controlled and why they developed

Proximate versus ultimate explanations

Proximate: the mechanism (how)

Ultimate: Evolutionary significance (why)

With your partner, write down a proximate and ultimate explanation

Fixed action pattern (FAP)

Sequence of unlearned behaviors

Nearly unchangeable Carried out to completion Sign stimulus (releaser)

behavior Example of an innate

behavior

Imprinting

Generally irreversible Sensitive period Imprinting stimulus Innate and learning

components Lorenz Proximate, ultimate

explanations?

Nature versus nurture

Can behavioral traits be treated like physical traits?

How do your determine whether genes, environment, or both cause behavior?

Example behaviors: intelligence, musical/artistic talent, love?

Directed movements

Strong genetic influence Kinesis versus taxis Migration

Migrating blackcaps kept in captivity exhibited behaviors of “migratory restlessness” at night

Migratory and nonmigratory blackcaps mated and subjected to both environments

40% of offspring exhibited “migratory restlessness”

Signals and communication

Signal causes change in another organism’s behavior

Difference between communication and language

Pheromones (reproductive and nonreproductive behaviors)

Auditory communication

Songs of birds are partly learnedCritical period

Some insects, such as male Drosophila, produce a song even when reared in isolationVery little variation, why?

Learning

Definition? How do we learn? Habituation: Loss of responsiveness

Spatial learning and cognitive maps Spatial learning

(Tinbergen): experience consists of spatial structures of the environmentUse of landmarks.

Reliable? Cognitive maps: Internal

representation of spatial relationships

Classical conditioning (Pavlov)

Operant conditioning (Skinner)

How natural selections leads to behavioral traits Variation exists: fraction of the species T.

elegans (garter snakes) had ability to recognize slugs by chemoreception

Increased fitness: That variation has higher chance to survive and reproduce (genes passed on)

Led to changes in the population over time

1. Your friend Jim comes to you with a problem: His dog barks too much. He tells you that it is getting worse and the only way he can get his dog to stop barking is to give it a treat. Explain to your friend what kind of learning the dog is exhibiting and what can be done about it.

2. Most birds cannot fly when they are first born, but only at a certain age. A scientists decides to isolate 2 groups of birds after being born. One group can practice flapping their wings at any point. The other’s groups wings are tied so that they cannot practice flapping. At the expected age, both groups are allowed to attempt to fly, and both groups do successfully with no apparent difference. What would account for these results. Innate, learned behavior? Both? Neither?

3. The magnolia warbler only breeds in spring/early summer. Propose a proximate and ultimate explanation for this situation.

Lab 11: Animal Behavior

Lab 11: Animal Behavior Concepts

innate vs. learned behaviorexperimental design

control vs. experimental hypothesis

choice chamber temperature humidity light intensity salinity other factors

Lab 11: Animal Behavior Hypothesis

Tentative, testable explanation It is the hypothesis in an experiment that is

tested Deduction

If hypothesis AND experiment THEN prediction

Lab 11: Animal Behavior Hypothesis development

Poor: I think pillbugs will move toward the wet side of a choice chamber.

Better: IF pillbugs prefer a moist environment, AND they are randomly placed on both sides of a wet/dry choice chamber and allowed to move about freely for 10 minutes, THEN most will be found on the wet side.

Lab 11: Animal Behavior Experimental design sample size

Foraging behavior

Optimal foraging theory: behaviors exist as a compromise between benefits of nutrition and cost of obtaining food

Predation must be a factor

Mating behavior

Promiscuous Strong bonds

Monogamous(sex morphology similar)

Polygamous

Polyandry(dimorphic Larger, Showy males)

Polygyny(dimorphicLarger, Showy females)

Factors influencing evolution of mating systems-Need of young-Paternity certainty

- certainty increases with external fertilization

Sexual selection Sexual selection (selective pressure)

evolution of male behavior and anatomy Stalked-eyed flies

Females more likely to mate with males with longer eyestalks

Why? Correlation between genetic disorders and inability to develop long eyestalks

Agonistic behavior

Ritualized Winner gains access to resources Physical and behavioral characteristics

involved Usually harm is not done

Game theory and behavior

Game theory evaluates alternative strategies where outcome depends on strategies of other individuals

Why don’t less fit mating strategies disappear?Depends on abundance of certain strategies

Prisoner’s dilemma (why cooperative succeeds)

Columnman

Remains silent

Columnman

defects

Rowman remains silent

3,3 0,5

Rowman defects

5,0 1,1

Altruism Cost/benefit of selfish vs. unselfish

behavior? Altruism reduces individual fitness but

increases fitness of others

Inclusive fitness Helping close relatives would

increase the inclusive fitness (own offspring and survival, reproduction of close relatives)

Hamilton’s ruleNatural selection would favor

altruistic behavior when rB > C

Social learning

Experience involves observing others Culture: information transfer through social

learning Vervet monkey alarm calls Memes (Richard Dawkins)

Sociobiology (E.O. Wilson)

Connects human culture to evolutionary theory

Social behaviors exist because they are perpetuated by natural selection

Does not mean all social behaviors are hardwired (nature vs. nurture)


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