Behavioral Ecology

Fixed Action Pattern (FAP)

A Fixed Action Pattern is an innate behavioral sequence that is triggered by a specific stimulus, known as a sign stimulus. These patterns are highly stereotyped and occur in the same way each time.

• Sign stimulus: An external cue that initiates the FAP.

• Example: The egg-rolling behavior in geese, triggered by the sight of an egg outside the nest.

Innate Behavior

Innate behaviors are genetically programmed and do not require learning or experience.

• Kinesis: A non-directional movement in response to a stimulus.

• Taxis: A directional movement toward or away from a stimulus.

• Migration: Seasonal movement of animals from one region to another.

Signals and Communication

Animals use signals to communicate, which can include chemical, auditory, and visual cues.

• Auditory communication: Use of sound to convey information.

• Imprinting: A form of learning occurring during a sensitive period, often early in life.

Learning

Learning involves modification of behavior based on experience.

• Habituation: Decreased response to a repeated stimulus.

• Spatial learning: Use of environmental cues to navigate.

• Associative learning: Linking two stimuli or events together.

• Classical conditioning: Associating a neutral stimulus with a meaningful one.

• Operant conditioning: Learning through rewards and punishments.

Cognition and Social Learning

Cognition refers to the mental processes involved in gaining knowledge and comprehension. Social learning occurs when individuals learn from others.

Evolution of Behavior

Behavioral traits can evolve through natural selection. Examples include:

• Foraging: Strategies for finding food.

• Honeybee communication: Waggle dance to indicate food location.

Mating Behavior and Mate Choice

Different mating systems exist in animal populations:

• Monogamous: One male and one female pair.

• Polygamous: One individual mates with several others.

• Polygyny: One male, multiple females.

• Polyandry: One female, multiple males.

• Parental care and mate choice: Investment in offspring affects mate selection.

Game Theory and Altruism

Game theory models strategic interactions in behavioral ecology. Altruism refers to behaviors that benefit others at a cost to oneself.

• Genetic basis for altruism: Kin selection and inclusive fitness.

Sociobiology

Sociobiology studies the evolutionary basis of social behavior.

Intro to Ecology

Ecology: Subfields

Ecology is the study of interactions between organisms and their environment. Subfields include:

• Biotic factors: Living components (e.g., plants, animals).

• Abiotic factors: Non-living components (e.g., temperature, water).

Factors Influencing Distribution

• Dispersal: Movement of individuals away from their origin.

• Biotic factors: Predation, competition, disease.

• Abiotic factors: Climate, soil, water availability.

Climate

Climate is a major factor influencing the distribution of organisms.

• Types: Global, regional, local, micro-climate.

• Influences: Sunlight, wind patterns, bodies of water, mountains, human activity.

Aquatic Ecosystems

Productivity

Productivity in aquatic ecosystems is limited by factors such as sunlight and nutrients.

• Zones: Photic, aphotic, benthic.

• Nutrient distribution: Affects primary productivity.

Aquatic and Terrestrial Biomes

Biomes are large ecological areas with distinct climate and organisms.

• Examples: Rivers, lakes, wetlands, estuaries, marine zones, tropical rain forest, desert, chaparral, savanna, temperate grassland, temperate forest, coniferous forest, tundra.

Population Ecology

Population

A population is a group of individuals of the same species living in a given area.

• Density: Number of individuals per unit area.

• Dispersion: Pattern of spacing among individuals (uniform, random, clumped).

• Demography: Study of vital statistics in populations.

Survivorship Curves

Survivorship curves show the proportion of individuals surviving at each age.

• Type I: High survival early, drops at old age (e.g., humans).

• Type II: Constant death rate (e.g., birds).

• Type III: High death rate early, survivors live long (e.g., oysters).

Population Growth Models

• Exponential growth: Population increases rapidly under ideal conditions.

• Logistic growth: Population growth slows as it approaches carrying capacity.

Equations:

• Exponential growth:

• Logistic growth:

Community Ecology & Ecosystems

Niche and Competition

A niche is the role an organism plays in its environment. The competitive exclusion principle states that two species competing for the same resources cannot coexist indefinitely.

Predation and Parasitism

• Predation: One organism kills and eats another.

• Parasitism: Parasite lives on or in host, causing harm.

• Defense strategies: Camouflage, chemical defenses, mimicry (Batesian and Müllerian).

Herbivory and Disease

• Herbivory: Animals eat plants.

• Disease: Pathogens and parasites affect host health.

Symbiosis

• Mutualism: Both species benefit.

• Commensalism: One benefits, other unaffected.

• Parasitism: One benefits, other harmed.

Community Structure

• Species diversity: Variety of species in a community.

• Relative abundance: Proportion of each species.

• Trophic structure: Feeding relationships among organisms.

• Limits to food chain length: Energy loss at each trophic level.

• Dominant species: Most abundant or highest biomass.

• Keystone species: Critical for maintaining community structure.

• Disturbance: Events that change community composition.

Energy and Biogeochemical Cycles

Productivity

• Primary productivity: Rate at which producers convert energy.

• Secondary productivity: Rate at which consumers convert energy from food.

• Limiting factors: Light, nutrients.

Biogeochemical Cycles

• Water cycle: Movement of water through environment.

• Nitrogen cycle: Conversion of nitrogen between forms.

• Carbon cycle: Movement of carbon through organisms and environment.

Effects of Human Activity

• Nutrient enrichment: Excess nutrients cause eutrophication.

• Atmospheric CO2: Increased greenhouse gases.

• Acid precipitation: Caused by pollutants.

• Ozone depletion: Loss of ozone in upper atmosphere.

Conservation Biology

Genetic, Species, and Ecosystem Diversity

Conservation biology focuses on preserving genetic, species, and ecosystem diversity.

Threats to Biodiversity

• Habitat destruction: Loss of living space.

• Invasive species: Non-native species disrupt ecosystems.

• Overexploitation: Excessive use of resources.

• Fragmentation: Breaking up habitats into smaller pieces.

Small Populations and Community Interactions

• Edge communities: Species interactions at habitat boundaries.

• Corridors: Connections to reduce impact of fragmentation.

Protected Areas and Restoration

• Protected areas: Nature reserves, biosphere reserves.

• Restoration: Bioremediation (using organisms to clean up pollution), biological augmentation (adding essential materials).

• Sustainable development: Balancing human needs with conservation.