Ch 51: Behavioral Biology (aka: Ethology)

1. Ch 51: Behavioral Biology (aka: Ethology)

2. Behavior is defined as what an animal does and how it does it • visible result of an animal’s muscular activity, chemicals secreted, or even learning

3. Questions used when studying behavior can be described as: • PROXIMATE: focus on the environmental stimuli (if any) that trigger a behavior as well as the genetic, physiological, & anatomical mechanisms underlying a behavioral act (“how” questions) • “How does day length influence breeding by red-crowned cranes?” 2) ULTIMATE: address the evolutionary significance of a behavior (“why” questions) • “Why did natural selection favor this behavior and not a different one?”

4. Proximate questions:  concern an animals immediate behavior • What stimulus triggers it? • What anatomical or physiological mechanisms are involved? • What underlying genetic factors are at work? • Questions that help us understand how a behavior occurs • Ultimate question:  help us understand why a behavior occurs • What is the adaptive value of the behavior? Proximate: Breed once the days become a certain length Ultimate: more food availability (increase reproductive success)

5. Although proximate & ultimate causation are distinct, they are related • Behavior is a combination of genes and environment (nature and nurture) Very small space 2.5 acres at San Diego Zoo

6. Behavior can be INNATE or LEARNED. INNATE BEHAVIOR: • present at birth; instinctual • Under strong genetic influence  remains essentially the same among organisms despite environmental differences (“developmentally fixed”) ultimate cause: beneficial for some behaviors to be performed “automatically” (without experience)

7. Birds have innate abilities to construct species specific forms of nests

8. Example = TAXIS: automatic, oriented movement toward or away from a stimulus • Many stream fish (ex: trout) exhibit a form of taxis called rheotaxis where they automatically orient themselves to face upstream into the current and therefore, towards the direction of food

9. LEARNED BEHAVIOR: Learning = the modification of behavior resulting from specific experiences Hi!

10.  Habituation = learning to ignore irrelevant stimuli or stimuli that convey little or no info. (“cry wolf” effect) *simple type of learning • Imprinting = form of learning that is limited to a specific time period in an animal’s life (critical or sensitive period); generally irreversible (ex: goslings imprinting on “mother”) *simple type of learning Click on picture

11. IMPRINTING! Imprinting gone wrong

12. Whooping crane conservation: learning a new migration route- following a person in a “whooping crane suit” who is flying an ultralight aircraft

13. Spatial Learning = Modification of behavior based on experience with the spatial structure of the environment • Location of nest sites, hazards, food, and prospective mates • Ex: Digger wasp experiment- wasp nest was in the center of a group of pinecones; scientist moved the circle of pinecones and the wasps still landed in the center of the pinecones

15.  Associative Learning = the ability to learn to associate one stimulus with another 1) classical conditioning: learning to associate an arbitrary stimulus with a reward or punishment (Pavlov’s dogs)

17. Associative Learning (cont.) 2) operant conditioning: “trial-and-error learning”; animal learns to associate one of its own behaviors with a reward or punishment and then tends to repeat or avoid that behavior (Skinner’s rat box)

19. Changes in innate behaviors are not always due to learning…  Maturation = development of neuromuscular systems that allow behavioral improvement (ex: flying)

20. SOCIAL BEHAVIOR:  any interaction between two or more animals, usually of the same species  includes: aggression, courtship, cooperation, deception

21. Examples of Social Behavior: • AGONISTIC BEHAVIOR = a contest of threatening and submissive behavior that determines which competitor gains access to a resource (ex: mate, food, territory) -observed in canine populations  dominance hierarchies, territoriality -much of this behavior involves ritual (no one seriously hurt); “play- fighting”

22. Video clip

23.  COURTSHIP AND MATE SELECTION: -complex behavior often consists of actions that seem to confirm that animals are of the same species but the opposite sex -females are usually more selective because they normally have a greater “parental investment” (more time and resources expended to produce offspring) -most males mate with as many females as possible; compete with other males; try to impress females; may have secondary sex characteristics (colorful plumage, etc.) Video clip

26.  COMMUNICATION: the intentional transmission of information between individuals -animals use visual, auditory, chemical, tactile and electrical signals -signal: behavior that causes a change in another animal’s behavior

28.  ALTRUISM: a behavior that reduces an individual’s fitness and increases the fitness of the recipient of the behavior Sounding the alarm! (at his own peril) Vampire bats often share their food! Belding’s ground squirrel