Sustaining Biodiversity: The Species Approach

1. Sustaining Biodiversity: The Species Approach Chapter 9

2. Core Case Study: The Passenger Pigeon: Gone Forever • Passenger pigeon hunted to extinction by 1900 • Commercial hunters used a "stool pigeon” • Archeological record shows five mass extinctions • Human activities: hastening more extinctions? SELF - STUDY

3. 9-1 What Role Do Humans Play in the Premature Extinction of Species? • Concept 9-1A We are degrading and destroying biodiversity in many parts of the world, and these threats are increasing. • Concept 9-1B Species are becoming extinct 100 to 1,000 times faster than they were before modern humans arrived on the earth (the background rate), and by the end of this century, the extinction rate is expected to be 10,000 times the background rate.

4. Human Activities Are Destroying and Degrading Biodiversity • Human activity has disturbed at least half to 83%* of the earth’s land surface • Filling in wetlands • Converting grasslands and forests to crop fields and urban areas • Degraded aquatic biodiversity *2005 Millennium Ecosystem Assessment

5. Extinctions Are Natural but Sometimes They Increase Sharply • Background extinction estimated = 0.0001% • Extinction rate Can be #/million/year or %/yr. • Mass extinction: causes? • Levels of species extinction • Local extinction – extinct in one area, but not others • Ecological extinction – so few individuals that species can’t fill their ecological role • Biological extinction – none anywhere on earth… this is forever.

6. Human Activities Cause Premature Extinctions: Pace Is Speeding Up • Premature extinctions due to • Habitat destruction • Overhunting • Where are the golden toads?

7. Human Activities Cause Premature Extinctions: Pace Is Speeding Up • Conservative estimates of extinction = 0.01-1% • Growth of human population will increase this loss • Rates are higher where there are more endangered species • Tropical forests and coral reefs, wetlands and estuaries—sites of new species—being destroyed • Speciation crisis – “death is one thing. The lack of births is another.” (loss of genetic biodiversity and diverse habitats can cause speciation to slow)

8. Effects of a 0.1% Extinction Rate

9. Endangered and Threatened Species Are Ecological Smoke Alarms • Endangered species – so few indiv. left that it could soon become extinct over all or part of natural range. • Threatened species (vulnerable species) – likely to become endangered soon… declining numbers

10. Endangered Natural Capital: Species Threatened with Premature Extinction

11. Characteristics of Species That Are Prone to Ecological and Biological Extinction The big, the slow, the tasty, those with valuable parts.

12. Percentage of Various Species Threatened with Premature Extinction

13. IUCN • International Union for the Conservation of Nature and Natural Resources – World Conservation Union • Red lists – in 2007: 16,306 species of plant and animals listed as in danger of extinction.

14. Science Focus: Estimating Extinction Rates Is Not Easy • Three problems • Hard to document due to length of time • Only 1.8 million species identified • Little known about nature and ecological roles of species identified • Document little changes in DNA • Use species–area relationship - 90% habitat loss causes 50% of species to become extinct • Mathematical models

15. 9-2 Why Should We Care about Preventing Premature Species Extinction? • Concept 9-2 We should prevent the premature extinction of wild species because of the economic and ecological services they provide and because they have a right to exist regardless of their usefulness to us.

16. Species Are a Vital Part of the Earth’s Natural Capital • Instrumental value (2 forms) • 1) Use value • Ecotourism: wildlife tourism • Genetic information • 2) Nonuse value • Existence value – appreciate that it exists • Aesthetic value – it’s pretty • Bequest value – willing to pay so it will be there for future generations • Ecological value – plays a role in ecosystem

17. Natural Capital Degradation: Endangered Orangutans in Tropical Forest

18. Natural Capital: Nature’s Pharmacy

19. Science Focus: Using DNA to Reduce Illegal Killing of Elephants for Their Ivory • 1989 international treaty against poaching elephants (although, poaching is on the rise) • Track area of poaching through DNA analysis of elephants • WWF - Wildlife crime scorecard • Elephants damaging areas of South Africa: Should they be culled?

20. Are We Ethically Obligated to Prevent Premature Extinction? • Intrinsic value: existence value • Edward O. Wilson: biophilia phenomenon • Biophobia

21. Science Focus: Why Should We Care about Bats? • Vulnerable to extinction • Slow to reproduce • Human destruction of habitats • Important ecological roles • Feed on crop-damaging nocturnal insects • Pollen-eaters • Fruit-eaters • Unwarranted fears of bats Be afraid of this one

22. 9-3 How do Humans Accelerate Species Extinction? • Concept 9-3 The greatest threats to any species are (in order) loss or degradation of its habitat, harmful invasive species, human population growth, pollution, climate change, and overexploitation.

23. Loss of Habitat Is the Single Greatest Threat to Species: Remember HIPPCO • Habitat destruction, degradation, and fragmentation • Invasive (nonnative) species • Population and resource use growth • Pollution • Climate change • Overexploitation

24. Causes of Depletion and Premature Extinction of World Species

25. Natural Capital Degradation: Reduction in the Ranges of Four Wildlife Species

26. Science Focus: Studying the Effects of Forest Fragmentation on Old-Growth Trees • Tropical Biologist Bill Laurance, et al. • How large must a forest fragment be in order to prevent the loss of rare trees? • Within 100m of the edge of plots, 36% of old-growth biomass is lost.

27. Case Study: A Disturbing Message from the Birds • 70% of species declining • Habitat loss and fragmentation of the birds’ breeding habitats • Forests cleared for farms, lumber plantations, roads, and development • Intentional or accidental introduction of nonnative species • Eat the birds • Everglades! SELF - STUDY

28. Case Study: A Disturbing Message from the Birds • Seabirds caught and drown in fishing equipment • Migrating birds fly into power lines, communication towers, and skyscrapers • Other threats • Oil spills • Pesticides • Herbicides • Ingestion of toxic lead shotgun pellets SELF - STUDY

29. Case Study: A Disturbing Message from the Birds • Greatest new threat: Climate change • Environmental indicators • Economic and ecological services SELF - STUDY

30. Distribution of Bird Species in North America and Latin America SELF - STUDY

31. The 10 Most Threatened Song Birds in the United States SELF - STUDY

32. Science Focus: Vultures, Wild Dogs, and Rabies: Unexpected Scientific Connections • Vultures poisoned from diclofenac in cow carcasses • More wild dogs eating the cow carcasses (increases milk production in cows) • Increase in wild dog population • More rabies spreading to people – more than ½ of rabies cases in the world SELF – STUDY But see Cats of Borneo

33. Some Deliberately Introduced Species Can Disrupt Ecosystems • Most species introductions are beneficial • Food • Shelter • Medicine • Aesthetic enjoyment • Nonnative species may have no natural • Predators • Competitors • Parasites • Pathogens

35. Case Study: The Kudzu Vine • Imported from Japan in the 1930s • “ The vine that ate the South” • Could there be benefits of kudzu?

36. Some Accidentally Introduced Species Can Also Disrupt Ecosystems • Argentina fire ant: 1930s • Pesticide spraying in 1950s and 1960s worsened conditions • Burmese python

37. Argentina Fire Ant Accidentally Introduced into Mobile, Alabama, U.S.

38. Prevention Is the Best Way to Reduce Threats from Invasive Species • Prevent them from becoming established • Learn the characteristics of the species • Set up research programs • Try to find natural ways to control them

41. Other Causes of Species Extinction • Population growth • Overconsumption • Pollution • Climate change

42. Other Causes of Species Extinction • Pesticides • DDT: Banned in the U.S. in 1972 • Bioaccumulation- increase in concentration of a pollutant from the environment to the first organism in a food chain • Biomagnification-increase in concentration of a pollutant from one link in a food chain to another

43. Bioaccumulation and Biomagnification

44. Case Study: Where Have All the Honeybees Gone? • Honeybees responsible for 80% of insect-pollinated plants • Dying due to? • Pesticides • Parasites • Bee colony collapse syndrome SELF - STUDY

45. Case Study: Polar Bears and Global Warming • Environmental impact on polar bears • Less summer sea ice • PCBs and DDT • 2007: Threatened species list SELF - STUDY

46. Illegal Killing, Capturing, and Selling of Wild Species Threatens Biodiversity • Poaching and smuggling of animals and plants • Animal parts • Pets • Plants for landscaping and enjoyment • Prevention: research and education

47. Animals Killed by a Poacher

48. Individuals Matter: Jane Goodall • Primatologist and anthropologist • 45 years understanding and protecting chimpanzees • Chimps have tool-making skills SELF - STUDY

49. Rising Demand for Bush Meat Threatens Some African Species • Indigenous people sustained by bush meat • More hunters leading to local extinction of some wild animals

50. 9-4 How Can We Protect Wild Species from Premature Extinction? • Concept 9-4A We can use existing environmental laws and treaties and work to enact new laws designed to prevent species extinction and protect overall biodiversity. • Concept 9-4B We can help to prevent species extinction by creating and maintaining wildlife refuges, gene banks, botanical gardens, zoos, and aquariums. • Concept 9-4C According to the precautionary principle, we should take measures to prevent or reduce harm to the environment and to human health, even if some of the cause-and-effect relationships have not been fully established, scientifically.