TR

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