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?

3. Passenger Pigeon

4. Human role in premature extinction……. • Degrading and destroying biodiversity in many parts of the world and these threats are increasing : 83% of the earth’s land surface • filling in wetlands, converting grasslands and forests to crop fields and urban areas • 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.

5. Human Activities Are Destroying and Degrading Biodiversity • Human activity has disturbed at least half of the earth’s land surface • Fills in wetlands • Converts grasslands and forests to crop fields and urban areas • Degraded aquatic biodiversity

6. Background Extinction………. • continuous low level of extinction • extinction rate : expressed as a percentage or number of species that go extinct/per million species per year 1/1,000,000=.000001 or .0001% ( estimated extinction rate before humans came on the scene)

7. Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up • Premature extinctions due to • Habitat destruction • Overhunting

8. Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up • Conservative estimates of extinction = 0.01-1.0% • 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

9. Animal Species Prematurely Extinct Due to Human Activities

10. Lost Natural capital Passenger pigeon Great auk Dodo Golden toad Aepyornis (Madagascar) Fig. 9-2, p. 185

11. Effects of a 0.1% Extinction Rate

12. Number of species existing Effects of a 0.1% extinction rate 5 million 5,000 extinct per year 14 million 14,000 extinct per year 50 million 50,000 extinct per year 100,000 extinct per year 100 million 0 50 100 150 200 Number of years until one million species are extinct Fig. 9-3, p. 186

13. Endangered and Threatened Species Are Ecological Smoke Alarms • Endangered species – has so individual survivors that the species could soon become extinct over all or most of it’s natural range • Threatened species - abundant in natural range , but numbers declining

14. Endangered Natural Capital: Species Threatened with Premature Extinction

15. Characteristic Examples Low reproductive rate (K-strategist) Blue whale, giant panda, rhinoceros Blue whale, giant panda, Everglades kite Specialized niche Elephant seal, desert pupfish Narrow distribution Bengal tiger, bald eagle, grizzly bear Feeds at high trophic level Fixed migratory patterns Blue whale, whooping crane, sea turtle African violet, some orchids Rare Snow leopard, tiger, elephant, rhinoceros, rare plants and birds Commercially valuable California condor, grizzly bear, Florida panther Large territories Stepped Art Fig. 9-5, p. 188

16. Percentage of Various Species Threatened with Premature Extinction

17. 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 • Mathematical models

18. Why Should We Care about Preventing Premature Species Extinction? • 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.

19. Species Are a Vital Part of the Earth’s Natural Capital • Instrumental value • Use value • Ecotourism: wildlife tourism • Genetic information • Nonuse value • Existence value • Aesthetic value • Bequest value • Ecological value

20. Natural Capital Degradation: Endangered Orangutans in a Tropical Forest

21. Endangered Scarlet Macaw is a Source of Beauty and Pleasure

22. Natural Capital: Nature’s Pharmacy

23. Science Focus: Using DNA to Reduce Illegal Killing of Elephants for Their Ivory • 1989 international treaty against poaching elephants • Poaching on the rise • Track area of poaching through DNA analysis of elephants • Elephants damaging areas of South Africa: Should they be culled?

24. Are We Ethically Obligated to Prevent Premature Extinction? • Intrinsic value: existence value • Edward O. Wilson: biophilia (inherent kinship with the natural world) • Biophobia – against certain organisms

25. 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

26. How do Humans Accelerate Species Extinction? 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.

27. 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

28. Causes of Depletion and Premature Extinction of World Species

29. NATURAL CAPITAL DEGRADATION Underlying Causes • Population growth • Rising resource use • Undervaluing natural capital • Poverty Direct Causes • Habitat loss • Pollution • Commercial hunting and poaching • Habitat degradation and fragmentation • Climate change • Sale of exotic pets and decorative plants • Overfishing • Introduction of nonnative species • Predator and pest control Causes of Depletion and Premature Extinction of Wild Species Fig. 9-10, p. 193

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

31. Science Focus: Studying the Effects of Forest Fragmentation on Old-Growth Trees • Tropical Biologist Bill Laurance, et al.- edges of forest fragments invaded by vines which take over • How large must a forest fragment be in order to prevent the loss of rare trees? – within 100 meters of the edge of a forest fragment 36% of the biomass of old growth trees is lost within 10-17 years

32. Case Study: A Disturbing Message from the Birds • 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

33. CaseStudy: 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 • Climate Change

34. Distribution of Bird Species in North America and Latin AmericaLoss of 93% of Brazil’s coastal rain forest

35. Science Focus: Vultures, Wild Dogs, and Rabies: Unexpected Scientific Connections • Vultures poisoned from diclofenac in cow carcasses • More wild dogs eating the cow carcasses • More rabies spreading to people

36. 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

37. Some Harmful Nonnative Species in the United States

38. Deliberately Introduced Species Purple loosestrife European starling African honeybee (“Killer bee”) Nutria Salt cedar (Tamarisk) Hydrilla Marine toad (Giant toad) Water hyacinth Japanese beetle European wild boar (Feral pig) Fig. 9-14a, p. 199

39. 7100 harmful invasive species introduced into the US Fig. 9-14b, p. 199

40. Accidentally Introduced Species Sea lamprey (attached to lake trout) Argentina fire ant Common pigeon (Rock dove) Brown tree snake Eurasian ruffe Formosan termite Zebra mussel Asian long-horned beetle Asian tiger mosquito Gypsy moth larvae Fig. 9-14b, p. 199

41. Deliberately introduced species Purple loosestrife European starling African honeybee (“Killer bee”) Nutria Salt cedar (Tamarisk) Hydrilla Marine toad (Giant toad) Water hyacinth Japanese beetle European wild boar (Feral pig) Accidentally introduced species Sea lamprey (attached to lake trout) Argentina fire ant Common pigeon (Rock dove) Brown tree snake Eurasian ruffe Formosan termite Zebra mussel Asian long-horned beetle Asian tiger mosquito Gypsy moth larvae Stepped Art Fig. 9-14, p. 199

42. Case Study: The Kudzu Vine • Imported from Japan in the 1930s • “ The vine that ate the South” – might spread as far as the Great Lakes by 2040 if climate change (global warming) occurs • Could there be benefits of kudzu? – source of food, for making paper

43. Kudzu Taking Over an Abandoned House in Mississippi, U.S.

44. SomeAccidentally Introduced Species Can Also Disrupt Ecosystems • Argentina fire ant: 1930s • Pesticide spraying in 1950s and 1960s worsened conditions • Burmese python –imported as a pet from Southeast Asia. Dumped in the Everglades. By 2100 in most of southern US

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

46. 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

47. Characteristics of Invader Species and Ecosystems Vulnerable to Invading Species

48. What Can You Do to Control Invasive Species ?

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

50. Other Causes of Species Extinction • Pesticides • DDT: Banned in the U.S. in 1972 • Bioaccumulation • Biomagnification