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