15 - Behavioural Ecology

Behavioural Ecology Overview

  • Course Info: Behavioural Ecology BIOL 1113 - Organisms and their Environment 1.

  • Acknowledgment: Recognition of Mi’kma’ki territory and responsibilities as treaty people.

Learning Objectives

  • Key topics in Behavioural Ecology:

    • Influence of genetics and learning on behavior.

    • Local movement versus long-range migration.

    • Foraging behavior and decision making.

    • Communication methods amongst organisms.

    • Social structures: Living in groups and altruism.

    • Diverse mating systems present in nature.

Basic Concepts of Behavioural Ecology

  • Behaviour Definition: Observable responses of organisms to stimuli.

  • Study Focus: Investigates how behavior affects survival and reproduction.

    • Ethology: Examines genetic/physiological mechanisms (proximate causes).

    • Adaptive Significance: Studies evolutionary impacts on reproductive success (ultimate causes).

  • Behavior Types: Combination of innate behaviors and learned experiences.

Case Study: Red Foxes

  • Research Background: Breeding red foxes for positive human interaction (started in 1959).

  • Breeding Outcomes:

    • Selective breeding over 50 generations led to observable behavior differences.

    • Notable genetic study by University of Illinois (2018): Key gene regions identified linking behaviors and domestication traits.

Genetic Influence on Behavior

  • Innate Behaviors: Genetically programmed, common across environments.

    • Fixed Action Patterns: Instinctual behaviors that continue until complete.

      • Example: Geese egg-rolling - sign stimulus initiates the response that improves fitness by ensuring offspring survival.

Learning Mechanisms

  • Learning Definition: Behavior modification based on experience.

  • Forms of Learning:

    • Habituation: Ignoring repeated stimuli.

    • Associative Learning: Behavioral change through stimulus-response associations.

      • Classical Conditioning: Involuntary response linked to paired stimuli (e.g., Pavlov's dogs).

      • Operant Conditioning: Behavior reinforced by consequences, involving trial-and-error learning.

Cognitive Learning

  • Definition: Problem-solving using conscious thought.

  • Examples: Chimpanzee box-stacking for food; ravens retrieving meat with tools.

Innate Behaviour and Learning Interactions

  • Integration: Behavior often combines innate and learned components (e.g., bird song learning).

  • Imprinting: Lifelong behavioral responses based on early critical period experiences (e.g., young geese).

Movement Patterns

  • Local Movement: Finding resources such as food and mates.

  • Kinesis vs. Taxis:

    • Kinesis: Non-directional movement in response to stimuli.

    • Taxis: Directional movement towards (positive) or away (negative) from a stimulus.

Long-Range Migration

  • Seasonal Movement Influences: Changing temperatures and food availability.

  • Examples of Migrators:

    • Birds: Seasonal migration patterns between regions.

    • Mammals: Wildebeest and caribou.

    • Insects: Monarch butterfly migrations involving multiple generations.

Migration Mechanisms

  • Piloting: Movement between familiar landmarks.

  • Orientation: Following compass bearings in a straight line.

  • Navigation: Compass and environmental adjustments to maintain migration paths (e.g., starlings).

Navigation in Animals

  • Utilization of environmental cues:

    • Sun, stars, Earth's magnetic field (e.g., homing pigeons).

    • Example: Green sea turtles migrate to specific nesting areas.

Foraging Behaviour

  • Resource Patch Decisions: Balance between remaining at resources vs. seeking new ones.

  • Optimal Foraging Theory: Strategies maximize benefits relative to costs (energy expenditure vs. energy gained).

Territoriality and Communication

  • Territoriality: Exclusive area defended for resource access; costs and benefits analyzed.

  • Communication Types:

    • Chemical, auditory, tactile, visual signals.

    • Examples: Courtship displays in peacock spiders and fireflies.

Social Structures in Animals

  • Group Living: Social behavior complexity increases in groups.

  • Predator Defense Mechanisms:

    • Increased vigilance through collective awareness (many-eyes hypothesis).

    • Protection strategies, including selfish herd dynamics.

Altruism in Animal Behaviour

  • Definition: Actions benefiting others at personal cost.

  • Kin Selection Theory: Enables reproductive success of relatives through altruism (inclusive fitness).

  • Examples: Hanuman langurs' infanticidal behavior to increase reproductive success after territorial takeover.

Mating Systems Overview

  • Fisher's Principle: 1:1 sex ratio maintained by natural selection.

  • Types of Mating Systems:

    • Promiscuous: Multiple partners for both sexes.

    • Monogamous: Exclusive mating pairs.

    • Polygamous: One individual mates with multiple partners (polygyny or polyandry).

Monogamy and Polygyny

  • Monogamous Relationships: Similar body structure; protective behaviors arise from mate-guarding, male assistance, or female enforcement hypotheses.

  • Polygynous Systems: Female resource dependence leads to male competition; common in resource-rich areas.

Polyandry and Sexual Dimorphism

  • Polyandry: Females mate with multiple males; often at a lower frequency than polygyny.

  • Sexual Dimorphism: Variations in size and characteristics within mating systems.