Ecology and Carrying Capacity Lecture

Introduction to Ecological Observations

• Common Observations: Noticing wildlife such as squirrels prompts questions about their behavior and ecology.
• Ecologists' Role: Ecologists ask questions about animals and their environment to understand ecosystems.

Key Concepts

Carrying Capacity

• Definition: The maximum population size an environment can sustain long-term with available resources.
• Examples of Resources: Food, water, shelter, space.

Population

• Definition: A group of individuals of the same species interacting regularly.
• Example: Squirrel population on a nature trail.

Factors Affecting Carrying Capacity

Limiting Factors

• Food, Water, Shelter: Basic resources required for survival.
• Space: Need for nesting and territory, even in non-territorial species like squirrels.
• Predation: Presence of predators such as birds of prey, cats, and snakes.

Density-Dependent Factors

• Examples: Food, water, shelter, space, predation, disease.

Density-Independent Factors

• Example: Natural disasters like wildfires.

Population Density

• Definition: The number of individuals in a specific area.
• Changes: Occurs due to births, deaths, immigration, and emigration.

Case Studies

Squirrels

• Environment: Nature trail with sufficient resources and predatory birds.
• Predators: Red-tailed hawks, kites, owls, and other animals.

Gulf Fritillary Butterflies

• Host Plant: Passionvine.
• Population Growth: Rapid due to butterfly egg laying.
• Limiting Factor: Passionvine leaf availability.
• Predators: Yellowjackets consume eggs and caterpillars.
• Human Intervention: Protecting caterpillars from predators by enclosing them, allowing safe development.

Conclusion

• Variation in Carrying Capacity: Depends on ecosystem and seasonal changes.
• Call to Action: Encouragement to observe local ecosystems and explore further learning.