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” Geological record shows five mass extinctions Human activities: hastening more extinctions?

3. Figure 9.1Lost natural capital: passenger pigeons have been extinct in the wild since 1900 because of human activities. The last known passenger pigeon died in the U.S. state of Ohio’s Cincinnati Zoo in 1914.

5. 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.

6. 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

7. Extinctions Are Natural but Sometimes They Increase Sharply • Background extinction • Extinction rate • Mass extinction: causes? • Poorly understood, but involve global changes in environmental conditions. • Levels of species extinction • Local extinction, or extirpation • Ecological extinction • Biological extinction

8. Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up (1) • Premature extinctions due to • Habitat destruction • Overhunting, or overexploitation

9. Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up (2) • Conservative estimates of extinction = 0.01-0.1% • Growth of human population will increase this loss to 10 000 times (to 1%) • 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

10. Animal Species Prematurely Extinct Due to Human Activities

11. Figure 9.3Effects of a 0.1% extinction rate.

12. Endangered and Threatened Species Are Ecological Smoke Alarms • Endangered species • International Union for the for the Conservation of Nature (IUCN), or the World Conservation Union. • Since 1960, published Red List • In 2007, listed 16, 306 animals and plants that are in danger of extinction—60% higher than in 1995. • Threatened species,vulnerable species • Characteristics of such species

13. African elephant Kirkland’s warbler Knowlton cactus Florida manatee Grizzly bear Figure 9.4 Endangered natural capital. Some species that are endangered or threatened with premature extinction largely because of human activities. Almost 30,000 of the world’s species and roughly 1,300 of those in the United States are officially listed as being in danger of becoming extinct. Most biologists believe the actual number of species at risk is much larger. Siberian tiger Utah prairie dog Golden lion tamarin Humpback chub Swallowtail butterfly Northern spotted owl Giant panda Whooping crane Black-footed ferret Blue whale Mountain gorilla Florida panther California condor Black rhinoceros Hawksbill sea turtle

14. 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 Figure 9.5 Characteristics of species that are prone to ecological and biological extinction. Question: Which of these characteristics helped lead to the premature extinction of the passenger pigeon within a single human lifetime?

15. Figure 9.6Endangered natural capital: percentage of various types of species threatened with premature extinction because of human activities (Concept 9-1A). Question: Why do you think fishes top this list? (Data from World Conservation Union, Conservation International, World Wide Fund for Nature, 2005 Millennium Ecosystem Assessment, and the Intergovernmental Panel on Climate Change)

16. 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 • Suggests species survive for 1 to 10 million years before going extinct. • Use species–area relationship • On average, 90% loss of habitat results in a 50% loss of species living in that habitat. • Mathematical models

17. 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. “It will take 5-10 million years for natural speciation to rebuild the biodiversity we are likely to destroy during your lifetime.”

18. Species Are a Vital Part of the Earth’s Natural Capital • Instrumental value – usefulness to us in providing ecological and economic services. • Use value • Ecotourism: wildlife tourism • Genetic information • Loss in diversity of crop species is cause for concern. • Food crops, recreation, scientific information, lumber, paper, etc. • Nonuse value • Existence value • Aesthetic value • Bequest value • Ecological value • Energy flow, nutrient cycling, and population control—the scientific principles of sustainability that sustain and support life on earth.

19. Figure 9.7Natural capital degradation: endangered orangutans in a tropical forest. In 1900, there were over 315,000 wild orangutans. Now there are less than 20,000 and they are disappearing at a rate of over 2,000 per year because of illegal smuggling and clearing of their forest habitat in Indonesia and Malaysia to make way for oil palm plantations. An illegally smuggled orangutan typically sells for a street price of $10,000. According to 2007 study by the World Wildlife Fund (WWF), projected climate change will further devastate remaining orangutan populations in Indonesia and Malaysia. Question: How would you go about trying to set a price on the ecological value of an orangutan?

20. Figure 9.8Natural capital: nature’s pharmacy. Parts of these and a number of other plant and animal species (many of them found in tropical forests) are used to treat a variety of human ailments and diseases. Nine of the ten leading prescription drugs originally came from wild organisms. About 2,100 of the 3,000 plants identified by the National Cancer Institute as sources of cancer-fighting chemicals come from tropical forests. Despite their economic and health potential, fewer than 1% of the estimated 125,000 flowering plant species in tropical forests (and a mere 1,100 of the world’s 260,000 known plant species) have been examined for their medicinal properties. Once the active ingredients in the plants have been identified, they can usually be produced synthetically. Many of these tropical plant species are likely to become extinct before we can study them.

21. Figure 9.9Many species of wildlife, such as this endangered scarlet macaw in Brazil’s Amazon rain forest, are a source of beauty and pleasure. These and other colorful species of parrots can become endangered when they are removed from the wild and sold (sometimes illegally) as pets.

22. 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?

23. Are We Ethically Obligated to Prevent Premature Extinction? • Intrinsic value, or existence value • Species have an inherent right to exist and play their ecological roles, regardless of their usefulness to us. • Edward O. Wilson: biophilia phenomenon • Biophobia

24. 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

25. 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.

26. Loss of Habitat Is the Single Greatest Threat to Species: Remember HIPPCO (1) Habitat destruction, degradation, and fragmentation Invasive (nonnative) species Population and resource use growth Pollution Climate change Overexploitation

27. Figure 9.10 Underlying and direct causes of depletion and premature extinction of wild species (Concept 9-3). The major direct causes of wildlife depletion and premature extinction are habitat loss, degradation, and fragmentation. This is followed by the deliberate or accidental introduction of harmful invasive (nonnative) species into ecosystems. NATURAL CAPITAL DEGRADATION Causes of Depletion and Premature Extinction of Wild Species 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

28. Figure 9.11 Natural capital degradation: reductions in the ranges of four wildlife species, mostly as the result of habitat loss and hunting. What will happen to these and millions of other species when the world’s human population doubles and per capita resource consumption rises sharply in the next few decades? Question: Would you support expanding these ranges even though this would reduce the land available for people to grow food and live on? Explain. (Data from International Union for the Conservation of Nature and World Wildlife Fund)

29. Loss of Habitat Is the Single Greatest Threat to Species: Remember HIPPCO (2) The Bali Mynah is distributed and endemic to the island of Bali, where it is the island's only surviving endemic species.  This rare bird was discovered in 1910 and is one of the world's most critically endangered birds.   In fact, it has been hovering immediately above extinction in the wild for several years. • Globally, habitat loss, greatest in temperate biomes, pace picking up in tropics. • Endemic species • Hawaii, the extinction capital of America—63% of species at risk. • Habitat islands • Habitat fragmentation

30. 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? http://www.learner.org/vod/vod_window.html?pid=2277

31. Case Study: A Disturbing Message from the Birds (1) • 70% of the worlds 10,000 birds are declining; 12% are threatened with extinction. • 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

32. One in every eight bird species (12%) is threatened with extinction. Three-fourths live in forests.

33. Case Study: A Disturbing Message from the Birds (2) • 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

34. Case Study: A Disturbing Message from the Birds (3) • Greatest new threat: Climate change • Environmental indicators • Live in every climate and biome • Respond quickly to environmental changes • Easy to track • Economic and ecological services

35. Figure 9.12Distribution of bird species in North America and Latin America. Question: Why do you think more bird species are found in Latin America than in North America? (Data from The Nature Conservancy, Conservation International, World Wildlife Fund, and Environment Canada).

36. Figure 9.13 The 10 most threatened species of U.S. songbirds. Most of these species are vulnerable because of habitat loss and fragmentation from human activities. An estimated 12% of the world’s known bird species may face premature extinction due mostly to human activities during this century. (Data from National Audubon Society) Black-capped vireo Golden-cheeked warbler Cerulean warbler Sprague’s pipit Bichnell’s thrush California gnatcatcher Kirtland's warbler Florida scrub jay Henslow's sparrow Bachman's warbler

37. 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

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

39. Figure 9.14 Some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.

41. Case Study: The Kudzu Vine Imported from Japan in the 1930s to control soil erosion. “ The vine that ate the South” Could there be benefits of kudzu?

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

43. Some Accidentally Introduced Species Can Also Disrupt Ecosystems • Argentina fire ant: 1930s • Pesticide spraying in 1950s and 1960s worsened conditions • Wiped out competitor ant species and made them more pesticide resistant. • Burmese python

44. Figure 9.16The Argentina fire ant, introduced accidentally into Mobile, Alabama, in the 1930s from South America (green area), has spread over much of the southern United States (red area). This invader is also found in Puerto Rico, New Mexico, and California. Question: How might this accidental introduction of fire ants have been prevented? (Data from S. D. Porter, Agricultural Research Service, U.S. Department of Agriculture)

45. Prevention Is the Best Way to Reduce Threats from Invasive Species Prevent them from becoming established Learn the characteristics of the successful invader species and the types of ecosystems that are vulnerable to invasion. Inspection of imports. Ballast water from cargo ships. Set up research programs to try to find natural ways to control them: predators, parasites, bacteria and viruses. Ground surveys and satellite observations to detect and monitor invasions to develop better models for predicting spread.

46. Figure 9.17Some general characteristics of successful invader species and ecosystems vulnerable to invading species. Question: Which, if any, of the characteristics on the right-hand side could humans influence?

47. Figure 9.18Individuals Matter: ways to prevent or slow the spread of harmful invasive species. Questions: Which two of these actions do you think are the most important? Why? Which of these actions do you plan to take?

48. Other Causes of Species Extinction (1) Population growth Overconsumption Pollution Climate change

49. Other Causes of Species Extinction (2) • Pesticides • DDT: Banned in the U.S. in 1972 • Bioaccumulation • Biomagnification

50. DDT in fish-eating birds (ospreys) 25 ppm DDT in large fish (needle fish) 2 ppm DDT in small fish (minnows) 0.5 ppm DDT in zooplankton 0.04 ppm DDT in water 0.000003 ppm, or 3 ppt