Sustaining Biodiversity: The Species Approach G. Tyler Miller’s Living in the Environment 14th Edition Chapter 9
Key Concepts Human effects on extinction rates Understanding biodiversity and extinction How human activities endanger wildlife Preventing extinction Reconciliation ecology
Species Extinction Local extinction Ecological extinction Biological extinction
Endangered and Threatened Species Endangered species Threatened (vulnerable) species Florida manatee Northern spotted owl (threatened) Gray wolf Florida panther Bannerman's turaco (Africa) © 2004 Brooks/Cole-Thomson Learning From Fig. 12-3 p. 227
Florida Manatee
Hawksbill Sea Turtle
Golden Lion Tamarin
Northern Spotted Owl
White Top Pitcher Plant
Giant Panda
Extinction Rates Background (natural) rate of extinction Mass extinction Extinction spasm Fig. 5-9 p. 96
Characteristics of Extinction Prone Species Fig. 12-4 p. 228
Extinction 99.9% of all species that ever lived are now extinct Great Auk Flightless sea bird that lived in colonies Existed in Iceland, British Isles, Scotland, Scandinavia, and Canada It’s feathers, fat (oil), eggs, and meat became desirable and so the bird was hunted to extinction The last known pair was found and killed in Iceland in 1844 No efforts were made to save the population of the birds
Problems Estimating Extinction Rates Extinction not easily documented over time Many species remain unidentified Little is known about most identified species
Estimated Extinction Rates Species Area Relationship Population viability analysis (PVA) Minimum Viable Population (MVP) Minimum Dynamic Area (MDA)
Estimating Extinction Rates Species-area relationships Population viability analysis (PVA) Minimum viable population (MVP) Minimum dynamic area (MDA)
Causes of Depletion of Wild Species Human population growth Increasing per capita resource use Endangered centers of biodiversity Environmental destruction Spread of opportunistic species
Causes of Extinction Habitat alteration Invasive species Pollution Population Overharvesting
Habitat Loss Elimination of Species through… Tropical Deforestation Destruction of the Coral Reef and wetlands Plowing grasslands Pollution of freshwater streams, lakes, and marine habitats
Habitat Fragmentation Creates 3 Problems Decrease in sustainable population size Increase in surface area or edge Creation of barriers
Causes of Premature Extinction of Wild Species Fig. 12-6 p. 231
Importance of Wild Species Rebuilding biodiversity is slow Instrumental value Genetic information Eco-tourism Ecological value Intrinsic value
Habitat Loss and Degradation Greatest threat to species “HIPPO” Habitat destruction Invasive species Population (humans) growth Pollution Overharvesting
Threats from Nonnative Species Fig. 12-12 p. 238 Arrival Roles of non- native species Prevention Examples (p. 235) See Case Study p. 237 Fig. 12-12 p. 238
Nonnative Species Beneficial Harmful Argentina Fire Ants- Southern States Brown Tree Snake- Guam
Solutions Improving inspection of goods into a country Identifying major nonnative invaders and passing laws to prevent their entry into countries Requiring ships to take more precautions when entering a port
Other Extinction Threats Hunting and Poaching Predators and Pest Control Exotic Pets and Decorative Plants Climate Change and Pollution
Protecting Wild Species: The Research and Legal Approaches International Treaties: CITES and CBD U.S. National Laws: Lacey Act Endangered Species Act Habitat recovery plans
Endangered Species Act Private versus public poverty rights Win-win compromises Weaken or strengthen the Act?
Protecting Wild Species: The Sanctuary Approach Wildlife refuges and protected areas Gene banks, botanical gardens, and farms Zoos and Aquariums
Reconciliation Ecology Establishing and maintaining new habitats Being good neighbors to wildlife Reward voluntary conservation efforts See Case Study p. 248
Conservation: What Can I Do? Fig. 12-16 p. 249