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?
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
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 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.
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)