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Chapter 35

Chapter 35. Behavioral Adaptations to the Environment. Leaping Herds of Herbivores Impalas of the African savanna are one of the most successful species, despite heavy pressure from predators Behavior is the key to the impala's success

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Chapter 35

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  1. Chapter 35 Behavioral Adaptations to the Environment

  2. Leaping Herds of Herbivores • Impalas of the African savanna are one of the most successful species, despite heavy pressure from predators • Behavior is the key to the impala's success • The study of animal behavior is essential to understanding animal evolution and ecological interactions

  3. THE SCIENTIFIC STUDY OF BEHAVIOR • 35.1 Behavioral ecologists ask both proximate and ultimate questions • Behavior: everything an animal does and how it does it • Includes unobservable activities such as learning • Early workers in the field of behavioral biology • Karl von Frisch studied honeybee behavior • Konrad Lorenz compared behavior of animals in response to different stimuli

  4. Niko Tinbergen pioneered behavioral ecology, the study of behavior in an evolutionary context • Proximate questions focus on immediate causes of a behavior • Ultimate questions focus on the evolutionary cause of a behavior

  5. 35.2 Early behaviorists used experiments to study fixed action patterns • Innate behavior: behavior performed the same way by all members of a species • Under strong genetic control but improves with experience • Fixed action patterns: innate unchangeable behavioral sequences • Triggered by a sign stimulus • Advantageous when behaviors must be performed without time for learning

  6. 35.3 Behavior is the result of both genes and environmental factors • Phenotypic traits-including behavior-are the result of both genetic and environmental influences • Studies of complex mating and parenting behaviors in prairie voles • Differences in oxytocin and vasopressin receptors in montane and prairie voles • Transgenic experiments with mice • A single gene may control much of prairie vole behavior

  7. Cross-fostering experiments • Experience during development can change later behavior • Conclusion: strong evidence that vole behaviors are the product of both genes and environment

  8. LEARNING • 35.4 Learning ranges from simple behavioral changes to complex problem solving • Learning: a change in behavior resulting from experience • Enables animals to respond to environmental conditions • Habituation: learning not to respond to a repeated uninformative stimulus • May increase fitness by allowing nervous system to focus on important stimuli

  9. 35.5 Imprinting is learning that involves innate behavior and experience • Imprinting: irreversible learned behavior • Limited to a sensitive period • Demonstrated in classic experiments by Konrad Lorenz • Important in formation of bonds between parents and young • Functions in salmon finding home stream • Plays a role in song development for many birds

  10. Video: Ducklings

  11. CONNECTION • 35.6 Imprinting poses problems and opportunities for conservation programs • Endangered cranes imprinted on foster parents would not breed with their own species • Operation Migration • Chicks bonded with planes used as surrogate mothers • Young birds learned migration routes

  12. 35.7 Animal movement may be a simple response to stimuli or involve spatial learning • Kinesis: random movement in response to a stimulus • Taxis: more or less automatic movement directed toward or away from a stimulus • Spatial learning: more complex than kinesis or taxis • Involves using landmarks to move through the environment • Example: Tinbergen wasp experiment

  13. LE 35-7a Direction of river current

  14. LE 35-7b Nest No nest Nest Nest No nest

  15. 35.8 Movements of animals may depend on internal maps • Cognitive map: internal representation of spatial relationships among objects in an animal's surroundings • Migration: regular back-and-forth movement between two geographic areas • Animals may use sun, stars, landmarks, or innate responses to environmental cues to navigate • Example: indigo buntings' star map

  16. LE 35-8 Paper Funnel- shaped cage Ink pad

  17. 35.9 Animals may learn to associate a stimulus or behavior with a response • Associative learning • Animal learns that a particular stimulus or response is linked to a reward or punishment • Trial-and-error learning • Animal learns to associate one of its own behavioral acts with a positive or negative effect • Animal repeats or avoids the response

  18. 35.10 Social learning involves observation and imitation of others • Social learning: learning by observing the behavior of others • Example: vervet monkey alarm calls

  19. 35.11 Problem-solving behavior relies on cognition • Cognition: ability of an animal's nervous system to perceive, store, process, and use information gathered by sensory receptors • Problem solving: ability to apply past experience to novel situations • Involves complex cognitive processes • Highly developed in some mammals • Observed in some bird species

  20. Video: Chimp Cracking Nut

  21. FORAGING AND MATING BEHAVIORS • 35.12 Behavioral ecologists use cost-benefit analysis in studying foraging • Foraging: food-obtaining behavior • Includes recognizing, searching for, capturing, and eating food items • Animals forage in many ways • Generalists eat all or most available foods (example: gulls) • Specialists eat only specific things (example: koalas)

  22. Search image: mechanism that enables finding a particular food efficiently • Optimal foraging theory: feeding behavior should provide maximal energy gain with minimal energy expense and risk • Occurs among many species when prey is plentiful • May be improved by group behavior

  23. 35.13 Mating behaviors enhance reproductive success • Several mating systems are found among animals • Promiscuous: no strong pair-bonds or lasting relationships between males and females • Monogamous: one male with one female • Polygamous: individual of one sex mating with several of the other sex

  24. Needs of offspring and certainty of paternity help explain differences in mating systems and parental care • Needy young generally have monogamous parents (example: many birds) • Mating and birth separated by time often lead to parental care by males (example: fish)

  25. 35.14 Mating behavior often involves elaborate courtship rituals • In many species, courtship rituals confirm that individuals are • Of the same species • Of the opposite sex • Are physically primed for mating • Are not a threat

  26. Courtship rituals are a group activity in some species • Members of one or both sexes choose mates from a group of candidates

  27. Video: Albatross Courtship Ritual Video: Blue-footed Boobies Courtship Ritual Video: Giraffe Courtship Ritual

  28. SOCIAL BEHAVIOR AND SOCIOBIOLOGY • 35.15 Sociobiology places social behavior in an evolutionary context • Social behavior: any interaction between two or more animals • Examples: courtship, aggression, cooperation • Sociobiology applies evolutionary theory to social behaviors • How they are adaptive • How they could have evolved by natural selection

  29. 35.16 Territorial behavior parcels space and resources • A territory is an area that is • Usually fixed in location • Inhabited by an individual • Defended from occupancy by other individuals of the same species • Territory size varies with species, function of the territory, and resources available • Territories are used for feeding, mating, and/or rearing young

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