behavioural ecology 10/27/25

Introduction to Animal Behavior

  • Definition: Observable responses of an organism to internal and external stimuli, influenced by genetic and learned behaviors.

Environmental Stimuli Affecting Behavior

  • Types of Environmental Stimuli:

    • Temperature

    • Odors

    • Humidity

    • Weather

  • Animals respond to various stimuli, both living (organic) and nonliving (inorganic), including lightning and loud sounds.

Nature vs. Nurture

  • Genetic Factors: Behavioral responses are influenced by inherited traits.

  • Learned Behaviors: Experiences and learning also play a significant role.

  • Complex Interactions: The balance between genetic predispositions and environmental influences shapes behavior over time.

Adaptation and Complexity of Behavior

  • Adaptation: Behaviors can evolve to be more complex due to natural selection.

  • Examples of Complex Behaviors:

    • Grey Whales: Use piloting techniques based on landmarks during migration from feeding to breeding areas, particularly around the Hawaiian Islands.

    • Bumblebees: Exhibit strong social structures and complex behaviors such as play and counting abilities.

    • Cephalopods (e.g., Octopi): Capable of tool use, such as using shells for hiding from predators and for hunting.

    • Primates: Show high adaptability, cognitive behaviors, and complex social structures.

Evaluating Observed Behaviors

  • Behaviors are typically observed at localized levels and can be influenced by factors such as day length and specific environmental cues.

  • Questions to Consider: What is the most complex behavior seen in animals?

Behavior Classification

Innate vs. Learned Behaviors

  • Innate Behaviors: Instinctive, genetically programmed actions that do not vary significantly.

    • Fixed Action Patterns: Inborn behaviors that occur in a predictable sequence and are not interrupted.

  • Learned Behaviors: Changes in behavior as a result of experiences and environmental interactions.

Behavior in Evolutionary Context

  • Behavior's Role: Observed behaviors contribute to the survivability and reproductive success of species, impacting their evolutionary success.

  • Immediate vs. Ultimate Causes:

    • Approximate Causes: Immediate impacts of a behavior, e.g., better foraging.

    • Ultimate Causes: Long-term evolutionary benefits, e.g., higher reproductive success leading to gene transmission across generations.

Psychological Mechanisms of Behavior

Ethology

  • The scientific study of animal behavior in natural environments, focusing on the genetic and physiological mechanisms.

Genetic Influences on Behavior

  • Examples of Genetic Behavior:

    • Honeybee cleaning behavior influenced by recessive genes for uncapping and removing diseased larvae.

Learning Mechanisms

Habituation

  • Simplest form of learning where organisms ignore repeated stimuli.

    • Example: Birds ignoring a scarecrow after repeated exposure.

Associative Learning

  • Learn through associations between stimuli and responses.

    • Classical Conditioning: Learning through association of an involuntary response with a stimulus (e.g., Pavlov's dogs).

    • Operant Conditioning: Learning through consequences, using rewards or punishments.

Examples of Conditioning

Classical Conditioning Example

  • Pavlov's Experiment:

    • Unconditioned Stimulus (UCS): Food

    • Unconditioned Response (UCR): Drooling

    • Conditioned Stimulus (CS): Bell

    • Conditioned Response (CR): Drooling at the sound of the bell without food.

Operant Conditioning Example

  • Skinner Box Experiment with Rats:

    • Lever pressing leads to food rewards or electric shocks, leading to learning through trial and error.

Cognitive Learning

  • Complex problem-solving and learning through experience.

    • Example: Chimpanzees stacking boxes to reach bananas.

Interaction of Innate and Learned Behaviors

  • Behaviors like song production can involve both genetic predispositions and learning from environmental cues.

  • Imprinting: A critical period where certain animals form attachments, exemplified in young birds imprinting on their mothers.

Migration and Navigation

  • Migration: Long-range seasonal movement often related to breeding and food availability.

    • Three mechanisms of navigation:

    1. Piloting: Using landmarks to navigate.

    2. Orientation: Following compass bearings, often using magnetic fields.

    3. Path Finding: Adjusting routes based on learned experiences.

Foraging Behavior

  • Animals optimize foraging to maximize energy intake while minimizing energy expenditure.

  • Optimality Theory: Suggests that behavior should maximize the benefits minus costs.

  • Examples in Foraging:

    • Short crabs choose to feed on medium-sized mussels to balance energy gain and expenditure.

    • Leafcutter ants forage during different times of day to avoid predators based on their size.

Communication in Animals

  • Communication can be classified into chemical, auditory, visual, and tactile types:

    • Chemical Communication: Marking territories and attracting mates, exemplified by pheromones in moths or queen bees controlling worker behavior.

    • Auditory Communication: Sound signals used in mating or territory establishment, often with a focus on optimal conditions for sound transmission.

    • Visual Communication: Displays of color and ornamentation to attract mates, as seen in peacocks.

    • Tactile Communication: Used in dark environments, such as bees performing the waggle dance to communicate food location through vibrational signals.

Social Structure and Altruism

  • Sociality: Living in groups can have benefits, such as increased protection from predators and easier access to resources, though it may also spread diseases.

  • Benefits of Social Living: Enhanced food location, mate attraction, and protection from predation due to increased vigilance.

  • Altruism: Cooperative behaviors that can benefit the group, often at some cost to the individual, requiring further exploration in subsequent discussions.