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Chapter 22 Sustaining Wild Species

Chapter 22 Sustaining Wild Species. Key Concepts. Human effects on biodiversity. Importance of biodiversity. How human activities affect wildlife. Management of wildlife. http:// www.youtube.com/watch?v=OKS4nz6_6Is. The Passenger Pigeon Gone Forever.

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Chapter 22 Sustaining Wild Species

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  1. Chapter 22Sustaining Wild Species

  2. Key Concepts • Human effects on biodiversity • Importance of biodiversity • How human activities affect wildlife • Management of wildlife

  3. http://www.youtube.com/watch?v=OKS4nz6_6Is

  4. The Passenger Pigeon Gone Forever How can a species that was once the most common bird in N. America become extinct in only a few decades? In the early 1800’s Alexander Wilson watched a single flock of migrating passenger pigeons (approx 2 million) darken the sky for 4 hours. By 1914 they were gone forever.

  5. The Passenger Pigeon Gone Forever • Main reasons for extinction of this species: • Uncontrolled commercial hunting • Loss of the bird’s habitat and food supply as forests were cleared to make room for farms and cities. • They were good to eat • Their feathers made good pillows • Their bones were used for fertilizer • Easy to kill because they flew in gigantic flocks • Nested in long, narrow colonies

  6. The Passenger Pigeon Gone Forever • Commercial hunters • would capture one pigeon alive • Sew its eyes shut • Tie it to a perch called a stool • Curious flocks would land beside the “stool pigeon” • Birds would then be shot or ensnared by nets • May trap more than 1,000 birds at once

  7. The Passenger Pigeon Gone Forever • Shooting galleries used live birds as target • In 1878, one professional pigeon trapper made $60,000 by killing 3 million birds at their nesting grounds near Petoskey, Michigan • By early 1880’s, only a few thousand birds remained. • Recovery of the species at this point was doomed because the females laid only one egg per nest. • March 20, 1900, a young boy in Ohio shot the last known wild passenger pigeon.

  8. The Passenger Pigeon Gone Forever • The Story of Martha- • The last passenger pigeon on earth was a hen named Martha- named for Martha Washington. • She died at the Cincinnati Zoo in 1914 • Her stuffed body is displayed at the Natural History Museum in Washington, D.C.

  9. 22.1 Human Impacts on Biodiversity A. Factors that increase biodiversity • Physically diverse habitat • Small - moderate environmental disturbances • Evolution

  10. B. Factors that decrease biodiversity • Environmental stress • Large disturbances • Extreme conditions • Limitation of essential resources • Introduction of alien species • Geographic Isolation

  11. Facts About Humans and the Earth • Have degraded 50% of the earths surface • Use waste or destroy 40% of the lands productivity

  12. Human Impacts on Extinction • Extinction rate is 1000 x faster as a result of human involvement • (Expected to grow to 10,000 x)

  13. Arctic Circle Arctic Circle Projected Biodiversity 1998-2018 60° EUROPE NORTH AMERICA ASIA 30°N Tropic Of Cancer Atlantic Ocean AFRICA Pacific Ocean Pacific Ocean 0° 150° 120° 90° 30°W 0° 60°E 90° 150° SOUTH AMERICA Indian Ocean Tropic Of Capricorn AUSTRALIA 30°S Antarctic Circle 60° ANTARCTICA Critical and endangered Threatened Stable or intact Projected Status of Biodiversity 1998–2018 Fig. 22.3, p. 552

  14. Biodiversity in the USA • 539 species have become extinct • Mostly due to habitat loss • 1/3 of plant and animal species may suffer premature extinction

  15. 1% Probably extinct 7% Critically imperiled 8% Imperiled 16% Vulnerable 1% Other 67% Secure or apparently secure Fig. 22.4, p. 554

  16. Water use and pollution and soil nutrient loss Freshwater supply and demand Food supply and demand Water availability Deforestation Deforestation Changes in precipitation and temperature Erosion, pollution, and changes in water flow CO2, CH4, N2O emissions Habitat change and fragmentation of habitat Forest product supply and demand Climate change CO2 emission Loss and fragmentation of habitat Loss and fragmentation of habitat Changes in transpiration and albedo Loss and fragmentation of habitat Loss of crop genetic diversity Habitat change Reduced resistance to change Biodiversity loss Fig. 22.2, p. 551

  17. How Serious is a Loss of Biodiversity? • Some argue that the threat is exaggerated… • We don’t know how many species there are • We don’t know the true value of all species in ecosystems • Estimates are based on models that lack data

  18. 22.2 Species Extinction Three Levels A. Local Extinction: Species is no longer found in an area it once was, but it is found in other areas

  19. B. Ecological Extinction: • So few that it can no longer play its ecological role

  20. C. Biological Extinction: • Species is no longer found anywhere on the earth • Biological Extinction is Forever • Irreversible loss of genes

  21. What are Endangered and Threatened Species? http://news.discovery.com/videos/why-endangered-species-are-doomed.htm Endangered: • So few individual survivors that the species can become extinct over all or part of its range Threatened or Vulnerable: • Still abundant in its natural range and may become endangered

  22. Rare Species: • Naturally small populations due to limited geographic range • Locally depleted by human activities • Vulnerable to extinction

  23. How Do Biologists Estimate Extinction Rates? Number and diversity of earth species is determined by interplay between extinction and speciation. Species-area relationship… • The number of species increases with the size of the area • A 90% loss of habitat results in 50% of species

  24. Estimation of Extinction Risks • Population Viability Analysis (PVA) • Risk assessment with math and stats sampling • Minimal Viable Population (MVP) • Smallest # of individuals necessary to ensure the survival of a population. At least a few thousand • Minimum Dynamic Area (MDA) • Minimum area of habitat needed to maintain the MVP

  25. Background vs. Mass Extinction Background Extinction- A small, naturally occurring, low rate extinction. Fossil records show 1-14 species a year (Approximately 1 species / million) 0.0001% per year

  26. B. Mass Extinction- A rise above the background rate, often catastrophic and global. Estimated to be five in the past 500 million years

  27. Carboniferous Cretaceous Devonian Jurassic Silurian Triassic Tertiary Ordovician Permian Quaternary Cambrian 408 245 2 Geological Periods Mass extinctions 800 600 Number of families of marine animals ? 400 200 0 570 505 438 360 286 208 144 65 0 Millions of years ago Fig. 22.10, p. 558

  28. Concerns of a New Extinction Crisis • 2/3 of mammals and plants will be extinct by the end of the century • Approx. 14,000 species go extinct each year • Thousands of times faster than the natural rate

  29. How is Today’s Extinction Crisis Different? • Massive loss in a few decades as opposed to thousands – millions of years • We are completely destroying habitat that served as the basis of recovery

  30. 22.3 Why Care About Biodiversity? The Earth’s Overall Biodiversity has 2 Types of Value: How do we value nature? • Instrumental Value: • Usefulness to humans • Intrinsic Value: • Because they exist regardless of their value

  31. Utilitarian (Use) -Economic goods(food, medicine, fuel, paper) - Ecological Services (photosynthesis, pollination of crops, pest control, air/water purification -Information(adaptation, genetic engineering) -Recreation(eco tourism) Non-Utilitarian (Nonuse) -Existence -Aesthetic -Bequest Instrumental Values

  32. Rauvolfia Southeast Asia Tranquilizer, high blood pressure medication Pacific yew Rosy periwinkle Pacific Northwest Ovarian cancer Madagascar Hodgkin's disease, lymphocytic leukemia Cinchona Foxglove South America Quinine for malaria treatment Europe Digitalis for heart failure

  33. 22.4 Causes of Premature Extinction 1. Habitat loss, degradation, and depletion -In U.S. the major disturbances are… *agriculture/grazing *development *outdoor recreation *pollution

  34. Habitat Fragmentation –A large, continuous area of habitat is reduced in area and divided into a patchwork of isolated areas.

  35. Former range Range today (34,000–54,000 left) Fig. 22.14d, p. 565 Asian or Indian Elephant

  36. Range 100 years ago Range today (about 2,300 left) Fig. 22.14a, p. 565 Indian Tiger

  37. Probable range 1600 Range today (600,000 left) African Elephant

  38. YOUR BOOK IS FROM 2004…. THE BLACK RHINO IS NOW EXTINCT. RIP.=( Range in 1700 Range today (about 2,400 left) Fig. 22.14b, p. 565 Black Rhino

  39. 22.5 Extinction Threats by Nonnative Species -U.S. has 50,000 Nonnative species -49% of 1,200 endangered and threatened species are threatened by nonnative species -Nonnative species fall into two categories… A.Deliberately Introduced B. Accidentally Introduced

  40. A. Deliberately Introduced -Supply 98% of U.S. food -Can have detrimental affects w/no predators, parasites, or competition to control numbers.

  41. KUDZU VINE: FERAL CATS

  42. B. Accidentally Introduced Many times they are transported in shipping products Brown Tree Snake Fire Ants

  43. 1918 2000 Expansion of the fire ant in southern states. Fig. 22.18, p. 570

  44. Tiger Mosquito Formosia termite

  45. 22-6. Extinction Threats from Commercial Hunting/Poaching -International trade of wild plant and animals is worth $10-$20 billion dollars per year. -1/4 of total is in illegal sales • Gorilla - $150,000 • Chimp - $50,000 • Rhino Horn - $13,000/lb. • Bushmeat - $150 million /yr.

  46. This family of Gorillas was Slaughtered for Bush meat

  47. Orphans of the Slaughter

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