1. Behavioral Ecology Chapter 37

2. Nature vs. Nurture Behavior To what degree do our genes (nature) and environmental influences (nurture) affect behavior?

3. Nature versus Nurture: Genetic Influences Lovebird Nesting Behavior Genetic role in nest making: Fischer lovebirds, Agapornis fischeri Peach-face lovebirds, Agapornis roseicollis Hybrid lovebirds exhibit intermediate behavior

4. Nature versus Nurture: Genetic Influences Garter Snake Experiments Genetic role in food preference In the wild:  Inland populations of garter snakes are aquatic  Coastal populations are terrestrial In the laboratory:  Inland snakes refused slugs  Coastal snakes readily accepted them  Hybrid snakes exhibited intermediate acceptance of slugs as food

5. Nature versus Nurture: Genetic Influences Garter Snake Experiments Sensory receptors are specific for prey Presented baby snakes with slug extract on cotton swabs  Coastal  Inland Genetic difference – physiological difference

6. Nature versus Nurture: Genetic Influences Experiments with Humans Twin Studies Look at characteristics of twins raised apart Many share common preferences in food, activity patterns, and mate selection

7. Nature versus Nurture: Environmental Influences Fixed Action Patterns (FAP) Specific behaviors elicited by a sign stimulus Learning A durable change in behavior brought about by experience

8. Nature versus Nurture: Environmental Influences Learning in Birds Imprinting: a simple form of learning Sensitive period Social interactions between parent and offspring during the sensitive period are important

9. Nature versus Nurture: Environmental Influences Learning in Birds Song Learning White-crowned sparrows  Species-specific song with different dialects Three groups:  Birds that heard no songs  Sang an undeveloped song as adults  Birds that heard White-crowned sparrows  Sang in that dialect as long as tape was played during a sensitive period  Birds that had adult tutor  Sang the tutor’s song even if a different species and no matter when tutoring began

10. Nature versus Nurture: Environmental Influences Associative learning 1. Classical Conditioning The presentation of two different types of stimuli at the same time Causes an animal to form an association between them 2. Operant Conditioning A stimulus-response connection is strengthened Training an animal by rewarding it

11. Other means of learning…. Animals may learn through insight, imitation, and habituation Insight learning An animal suddenly solves a problem without any prior experience with the problem Habituation An animal no longer responds to a repeated stimulus

12. Mating Behaviors Sexual Selection Adaptive changes that increase ability to attract a mate Influences fitness Three influences on mating: Female Choice Male Competition Human Mating

13. 1. Female Choice Two Hypotheses: Good Genes Hypothesis Females choose mates on basis of traits that improve survival Run-away Hypothesis Females choose mates on basis of traits that improve appearance

14. 2. Male Competition Males can produce many offspring because continuously produce sperm in large numbers Less time and energy invested in reproduction Males compete to inseminate as many females as possible Cost-benefit analyses Is the benefit of access to mating worth the cost of competition among males??

15. 2. Male Competition Males and females have separate dominance hierarchies Higher-ranking animal has greater access to resources than a lower-ranking animal Dominance is decided by confrontations

16. 3. Mating in Humans Human Males Compete Humans are dimorphic Men are larger and stronger likely as result of past selection by females Males pay a price - the average life span is seven years less than females!

17. Sociobiology Applies the principles of evolutionary biology to the study of social behavior in animals Hypothesis Living in a society has a greater reproductive benefit than reproductive cost Benefits of Group Living Helps an animal avoid predators, rear offspring, and find food Disadvantages to Group Living Competition among members of the group for resources Exposes group members to illnesses and parasites

18. Sociobiology Helpers at the Nest Minimal short-term reproductive sacrifice made to maximize future reproductive potential Helper contributes to survival of kin

19. Sociobiology and Human Culture Humans live in organized societies Culture of a human society involves a wide spectrum of customs Earliest organized societies may have been the “hunters-gatherers” Predatory lifestyle likely encouraged the evolution of intelligence and the development of language

20. Animal Communication Communication 4 types communication signals: Chemical Auditory Visual Tactile

21. Animal Communication Chemical Communication Pheromones Powerful chemical signals passed in low concentration May be released into the air or used in territory marking

22. Animal Communication Auditory Communication Very rapid and can be modified for specific situations

23. Animal Communication Visual Communication Most used by diurnal species-must be able to be seen Plumage, courtship “dances”, aggressive displays, etc

24. Animal Communication Tactile Communication Occurs when one individual touches another