Chapter 15 - Endangered Species Lecture Notes

Chapter 15 - Endangered Species

1⃣ Valuing Biodiversity

  • Economic Value: This includes values that derive from:

    • Direct Use: Where an organism is harvested, such as in activities like hunting and fishing.

    • Indirect Use: Where an organism is appreciated for its presence, as seen in wildlife watching and photography.

  • Examples of Economic Values:

    • A vast number of medicines, foods, and other commercial products are derived from natural sources.

    • The role of ecotourism, particularly in tropical rainforests.

  • Ethical / Intrinsic Value: This refers to the idea of valuing species for their own sake, independent of their economic benefits.

  • Ecological Values:

    • Species can become extirpated (locally extinct) when they are lost from part of their natural range.

    • A species is considered endangered when it exists in such low numbers that it cannot complete its ecological roles, thus reducing the ecosystem's ability to function.

2⃣ Main Pressures Causing Extinction

  • The focus on extinction has mainly been on vertebrates.

  • Tropical ecosystems are degrading and being destroyed rapidly due to several factors:

    • Agriculture: Expansion into natural lands for farming.

    • Logging: Deforestation for timber harvesting.

    • Road Building / Development: Infrastructure projects that fragment habitats.

  • Habitat Change: Humans now cover approximately 75% of Earth's terrestrial surface, and nearly 50% of wetlands were lost between 1970 and 2000, with a significant portion still under threat.

    • Habitat loss accounts for approximately 80% of all species-at-risk in Canada.

  • Groups at Risk:

    • Reptiles, amphibians, invertebrates, and lichens are among the most at risk.

    • Plants: High risk of endangerment.

    • Fish: Moderate risk of endangerment.

  • Key Facts:

    • About 90% of endangered birds and mammals in Canada are found in the southern regions.

    • Habitat loss is considered the most significant factor driving species to become endangered.

    • Chemical causes of species endangerment are often difficult to confirm.

3⃣ Vulnerability to Extinction

  • Species Most Vulnerable:

    • Species that are hunted for food or products.

    • Large-bodied species.

    • Species with small populations and limited distribution.

    • Island species.

    • Species at high trophic levels.

    • Species with low reproductive potential.

    • Species whose behaviors increase exposure to human activities.

4⃣ Responses to Biodiversity Loss

  • International Response:

    • CITES (Convention on International Trade in Endangered Species): Regulates international trade in wildlife to prevent extinction, with species categorized under Appendices I, II, III depending on their level of threat.

  • Canadian Response:

    • SARA (Species at Risk Act):

    • Purpose: Establish the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as an independent group of experts.

    • Requires scientific assessments to guide decision-making.

    • Provides legal protection for endangered species and their critical habitats.

    • Recognizes the need for compensation related to habitat restrictions.

    • Creates a public registry for transparency.

    • Must be consistent with international agreements.

  • SARA Process:

    1. Monitoring

    2. Species Assessment

    3. Response

    4. Recovery Program

    5. Evaluation

5⃣ Protected Areas

  • International Targets:

    • 13% of terrestrial areas and 10% of marine areas are targeted for protection.

  • IUCN (International Union for Conservation of Nature) Protected Area Categories:

    1. Ia: Strict Nature Reserve

    2. Ib: Wilderness Area

    3. II: National Park

    4. III: Natural Monument

    5. IV: Habitat/Species Management Area

    6. V: Protected Landscape

    7. VI: Sustainable Use Areas

  • Canada’s Protected Areas:

    • Parks Canada Mandate:

    • Maintain Ecological Integrity as per National Parks Act, which means the ecological condition characteristic of a natural region will likely persist. This includes native species compositions, abundance, and ecosystem processes.

  • Ecosystem Approach: Aligns with ecological integrity as a goal, utilizing methods that support this integrity.

6⃣ Big-Picture Summary (Exam Version)

  • This lecture outlines the importance of biodiversity, the reasons species become extinct, and the responses to these challenges. The core goals are to protect and present representative examples of Canada’s natural and cultural heritage while ensuring ecological integrity for future generations.

  • Key Points to Remember:

    • Biodiversity contributes economic, ecological, and ethical value.

    • Major causes of extinction include habitat loss, overharvesting, pollution, introduced species, and predator control.

    • Habitat loss is the primary driver of species endangerment, particularly in southern Canada.

    • Vulnerability to extinction is influenced by various factors including species size, behavior, reproductive patterns, and habitat.

    • Global responses include CITES and protected areas while Canada’s initiatives include SARA, national parks, and an emphasis on ecological integrity.

7⃣ How to Think About This on an Exam 🎯

  • To address a question such as "Explain the major causes of species extinction and evaluate conservation responses," structure your answer as follows:

    • Start by discussing habitat loss.

    • Include additional factors such as overharvesting and fragmentation of habitats.

    • Explain the vulnerability of particular species based on their characteristics.

    • Conclude with mentions of CITES, SARA, and protected areas as part of conservation responses.