Behavioral Ecology

Behavioral Ecology

• Behavioral ecology: the study of how behaviors arise due to ecology and evolution
  • Behavior: an animal’s response to a stimulus (internal or external)
  • Nature vs nurture (genetic and environmental factors)
  • Allow for survival and reproduction
    • Subject to natural selection

Understanding Behavior

• Proximate cause: how a behavior occurs or how it is modified

  • What was the stimulus to cause the behavior?
  • How does the “nurture” component affect behavior (ie how do the experiences during growth and development influence the response)?

• Ultimate cause: why a behavior occurs (in context of natural selection)

  • How does the behavior help the animal survive and reproduce?
  • How does the “nature” component affect behavior (ie what is the evolutionary basis of the behavior)?

Types of Behavior

• Behavior can be innate or learned
  • Innate behaviors: developmentally fixed 
  • Hereditary, born behaviors, do not need to learn them
  • Experience during growth has no obvious effect 
  • Learned behaviors: depend on environmental influence
  • Experiences DO affect these behaviors
  • High variation in a population

Innate Behaviors

• Fixed action patterns (FAPs): a sequence of unlearned acts directly linked to a stimulus
  • Actions are unchangeable
  • Carried out to completion
  • Triggered by a sign stimulus (external cue)
  • Example: stickleback fish
• Innate behaviors are inherited
  • Unlearned behavior
  • Environmental indifference - performed the same way by all members of a species
  • Ensures that activities essential to survival are performed correctly without practice
  • Eg. goose
• Migration: a regular, long-distance change in location
  • Triggered by environmental cues
  • Sun’s position
  • Earth’s magnetic field
  • Celestial cues
• Signal: a stimulus generated and transmitted from one animal to another; animal communication
  • Examples: visual, auditory, tactile, electrical, chemical
  • Pheromones: chemicals emitted by members of a species that can affect other members of the same species
  • Stimulus response chains: when a response to a stimulus serves as the next stimulus for a behavior
    • Seen in animal courtships
  • Body movement
    • Example: waggle dance in bees 

Communication and Signals

• Pheromones: chemicals emitted by members of one species that affect other members of the species (eg. Queen bee, fruit fly, fish)
• Visual signals: eg. warning flash of white of a mockingbird's wing
• Tactile (touch): eg. male fruit fly taps female fly
• Auditory signals: screech of blue jay or song of warbler

Directed Movements (Innate Behaviors)

• Directed movements: movements towards or away from a stimulus
  • Kinesis: random movement in response to a stimulus; non directional
  • Taxis: directional movement towards (positive) or away from (negative) a stimulus
  • Phototaxis: movement in response to light
  • Chemotaxis: movement in response to chemical signals
  • Geotaxis: movement in response to gravity

Learned Behaviors

• Learning: the modification of behavior based on specific experiences
• Imprinting: a long-lasting behavioral response to an individual
  • Happens during a sensitive period of development (usually very early in life)
  • Imprinting occurs on the first individual they encounter
    • Example: ducks following their mother
• Spatial learning: establishing memories based upon the spatial structure of the animal’s surroundings
  • Some animals form a cognitive map or use landmarks as environmental cues
  • Example: birds finding their hidden nests
• Associative learning: the ability to associate one environmental feature with another
  • Example: associating monarch butterflies with a foul taste
• Social learning: learning through observations and imitations of the observed behaviors
  • Example: chimps breaking open oil palm nuts

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