SOCIAL INTERACTIONS

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Chapter 46

• SOCIAL INTERACTIONS

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Ethology

• The study of the behavior of organisms in their
  natural environment

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Mechanisms Underlying Behavior

• Genetic Basis of Behavior
• Involves coordinated responses to internal and
  external responses
• Genes contribute in an indirect way
• e.g., garter snakes in California
  (coastal/inland)
• Hormonal Effects on Behavior
• Hormones signaling molecules
• e.g., songbirds in response to photoperiod
  changes

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Behavior Response

• Animals depend on structural and physiological
  mechanisms that govern behavior response to
  environmental cues.
• Two categories
• Instinctive (innate)
• learned

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1. Innate (Instinctive) Behavior

• Components of the nervous system allow an animal
  to accomplish complex, stereotyped responses to
  certain environmental cues
• Fixed action patterns
• Simple, lasting long, resistant to changes
• e.g. red-spot packing gull chicks
• egg- rolling goose
• swallowing reflexes

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Male song
Song of female experimentally converted to singer
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2. Learned Behavior

• Incorporates information that has been gained
  from specific experience
• Imprinting Konrad Lorenz exp. (1930s),
  Canadian geese story
• Habituation
• Operant Conditioning (Trial-and-error learning)
• Classical Conditioning
• Spatial (Latent) learning
• Insight Learning

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The Adaptive Value of Behavior

• Behavioral Evolution
• Reproductive success refers to the survival and
  production of offspring by
• adaptive behavior,
• selfish behavior,
• altruistic behavior, and
• natural selection (on feeding behavior and mating
  behavior) ? adaptive reproductive behavior

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• Evolution of Altruism
• Reduction in helpers Increased reproduction
  of helped.
• Human Behavior
• The behavior is valuable in the transmission of
  an individual genes
• Selfish / altruistic behavior of human can be
  tested w/o justifying the behavior,
• e.g., adopting children

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Social Life

• Social behavior is the the tendency of
  individual animals to enter into cooperative,
  interdependent relationships with others of their
  kind ? requires
• communication signals
• Pheromones
• Visual signals
• Acoustical signals
• Tactile signals

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Round dance signals food close to hive
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Waggle dance signals food 100 meters from hive
Orientation of straight run shows direction to
food
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Subordinate member of a wolfpack
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Cooperative defensive behavior among musk oxen
(Ovibos moschatus)
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Costs of Social Life

• Increased competition for food, mates, and other
  limiting resources
• Increased vulnerability to disease and parasitism
• Risk of exploitation by other group members

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Social Insects

• Workers in colonies of social insects are
  sterile e.g. termites and honeybees
• These colonies are extended families
• Workers pass on their genes indirectly by helping
  relatives reproduce