1. Chapter 9 Sustaining Biodiversity: The Species Approach
The last word in ignorance is the person who says of an animal or plant: “What good is it?”… If the land mechanism as a whole is good, then every part of it is good, whether we understand it or not. Harmony with the land is like harmony with a friend; you cannot cherish his right hand and chop off his left.
- Aldo Leopold

2. Core Case Study: Polar Bears and Global Warming
20,000-25,000 in the Arctic
Most calories in winter from seals on sea ice
Environmental impact on polar bears
Less summer sea ice from global warming
Could be gone from wild by 2100
2008: Threatened species list
Figure 9.1: On floating ice in Svalbard, Norway, a polar bear feeds on its seal prey. Polar bears in the Arctic could become extinct sometime during this century if projected atmospheric warming melts much of the floating sea ice on which they hunt seals. Question: What do you think about the possibility that the polar bear might become extinct mostly because of human activities? Explain.

3. 9-1 What Role Do Humans Play in the Extinction of Species?
Concept 9-1 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. Extinctions Are Natural but Sometimes They Increase Sharply (1)
Biological extinction
No species member alive
Background extinction
Natural low rate of extinction
Extinction rate
Percentage or number of species that go extinct in a certain time period

5. Extinctions Are Natural but Sometimes They Increase Sharply (2)
Mass extinction
3-5 events
50-95% of species became extinct
From global changes in environmental conditions: major climate change, volcanoes, asteroid impacts
Levels of species extinction
Local extinction
Ecological extinction
Biological extinction

6. Some Human Activities Are Causing Extinctions
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
Pollution of land and water

7. Extinction Rates Are Rising Rapidly
Current extinction rate is at least 100 times higher than typical background rate of .0001%
Will rise to 10,000 times the background rate by the end of the century
Rate will rise to 1% per year
¼ to ½ of the world’s plant and animal species

8. Extinction Rates Are Rising Rapidly
Conservative estimates of extinction = %
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

9. Endangered and Threatened Species Are Ecological Smoke Alarms
Endangered species
So few members that the species could soon become extinct
Threatened species (vulnerable species)
Still enough members to survive, but numbers declining -- may soon be endangered

10. Endangered and Threatened Species What Are There Characteristics?
Big
Slow
Tasty
Valuable parts
Behaviors that make them easy to kill
Figure 9.3: This diagram shows the characteristics of species that can put them in greater danger of becoming extinct. Question: Which of these characteristics might possibly contribute to the extinction of the polar bear (Core Case study) during this century?

11. Endangered Natural Capital: Species Threatened with Premature Extinction
Sumatran Tiger: < 60 Mexican Gray Wolf: 60
Figure 9.2: Endangered natural capital: These four critically endangered species are threatened with extinction, largely because of human activities. More than 17,300 of the world’s species, including 1,318 species in the United States, were officially listed in 2009 as endangered or threatened species. The number below each photo indicates the estimated total number of individuals of that species remaining in the wild. These and thousands of other species may disappear forever during your lifetime. According to most biologists, the actual number of species at risk is much larger. Question: What kinds of human activities to you think are putting these four animals in danger?
(a) Sumatran tiger: less than 60 in Sumatra, Indonesia
Fig. 9-2, p. 193

12. Endangered Natural Capital: Species Threatened with Premature Extinction
California Condor: Whooping Crane: 210
Figure 9.2: Endangered natural capital: These four critically endangered species are threatened with extinction, largely because of human activities. More than 17,300 of the world’s species, including 1,318 species in the United States, were officially listed in 2009 as endangered or threatened species. The number below each photo indicates the estimated total number of individuals of that species remaining in the wild. These and thousands of other species may disappear forever during your lifetime. According to most biologists, the actual number of species at risk is much larger. Question: What kinds of human activities to you think are putting these four animals in danger?
(a) Sumatran tiger: less than 60 in Sumatra, Indonesia
Fig. 9-2, p. 193 12

13. Percentage of Various Species Threatened with Premature Extinction
Figure 9.4: Endangered natural capital.
This graph shows the estimated percentages of various types of known species that are threatened with extinction because of human activities (Concept 9-1). Question: Why do you think plants (see Photo 4 in the Detailed Contents) and fish species top this list? (Data from International Union for Conservation of Nature, Conservation 2009)
Fig. 9-4, p. 194

14. Science Focus: Estimating Extinction Rates
Three problems
Hard to document due to length of time
Only 1.9 million species identified
Little known about nature and ecological roles of species identified
Approaches
Study extinction rates over last 10,000 years and then compare with the fossil record
Use species–area relationship
Mathematical models

15. Case Study: The Passenger Pigeon: Gone Forever
Once one of the world’s most abundant birds
Audubon: flock took 3 days to fly over
Passenger pigeon hunted to extinction by 1900
Habitat loss
Commercial hunting
Easy to kill: flew in large flocks and nested in dense colonies
Figure 9.5: Because of human activities, the North American passenger pigeon became extinct in the wild in In 1914, the world’s last known passenger pigeon died in a zoo in the U.S. city of Cincinnati, Ohio.

16. 9-2 Why Should We Care about the Rising Rate of 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.

17. Why Should We Prevent Extinctions? TOP 4 REASONS
Species provide natural resources and natural services
Insects for pollination
Birds for pest control
Most species contribute economic services
Plants for food, fuel, lumber, medicine
Ecotourism
It will take 5-10 million years to regain species biodiversity
Many people believe species have an intrinsic right to exist

18. Natural Capital Degradation: Endangered Orangutans in a Tropical Forest
Figure 9.6: Natural capital degradation.
These endangered orangutans are shown in their rapidly disappearing tropical forest habitat. In 1900, there were over 315,000 wild orangutans, which are found only in the tropical forests of Indonesia and Malaysia. According to the WWF, today there are fewer than 56,000 left in the wild (90% of them in Indonesia). These highly intelligent animals are disappearing at a rate of more than 1,000–2,000 per year because of illegal smuggling and the clearing of their tropical forest habitat to make way for plantations that supply palm oil used in cosmetics, cooking, and the production of biodiesel fuel. An illegally smuggled, live orangutan sells for a street price of up to $10,000. Without urgent protective action, the endangered orangutan may be the first great ape species to become extinct, primarily because of human activities. Question: What difference will it make if human activities cause the extinction of the orangutan?
Fig. 9-6, p. 195

19. Natural Capital: Nature’s Pharmacy
Figure 9.7: Natural capital.
These plant species are examples of nature’s pharmacy. Their scientific names (see Supplement 5, p. S18–S19) and some of their medicinal uses are shown as well. Parts of these plants as well as 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. Once the active ingredients in the plants have been identified, scientists can usually produce them synthetically. The active ingredients in nine of the ten leading prescription drugs originally came from wild organisms. Many of the world’s tropical plant species are likely to become extinct before we can even study them. Question: Which of these species, if any, might have helped you or people you know to deal with health problems?
Fig. 9-7, p. 196

20. Endangered Hyacinth Macaw is a Source of Beauty and Pleasure
Figure 9.8: Many species of wildlife such as this endangered hyacinth macaw are sources of beauty and pleasure. This species of parrot is found in fairly open woodlands and swamps in several areas of Brazil, Bolivia, and Paraguay. This and other colorful species of parrots have become endangered because many birds have been removed from the wild and sold (sometimes illegally) as pets.
Fig. 9-8, p. 197

21. 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.
Pilot Whale Hunt, Faeroe Island

22. 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

23. Habitat Fragmentation
Large intact habitat divided by roads, crops, urban development
Leaves habitat islands
Blocks migration routes
Divides populations
Inhibits migrations and colonization
Inhibits finding food
National parks and nature reserves as habitat islands

24. Causes of Depletion and Premature Extinction of World Species
Figure 9.9: This figure illustrates both the underlying and direct causes of depletion and extinction of wild species resulting from human activities (Concept 9-3) (see Figure 1-9, p. 13). The biggest cause is habitat loss, degradation, and fragmentation. This is followed by the deliberate or accidental introduction of harmful invasive (nonnative) species into ecosystems. Question: What are two direct causes that are specifically related to each of the underlying causes?
Fig. 9-9, p. 198

25. Natural Capital Degradation
Causes of Depletion and Extinction of Wild Species
Underlying Causes
• Population growth
• Rising resource use
• Undervaluing natural capital
• Poverty
Direct Causes
Figure 9.9: This figure illustrates both the underlying and direct causes of depletion and extinction of wild species resulting from human activities (Concept 9-3) (see Figure 1-9, p. 13). The biggest cause is habitat loss, degradation, and fragmentation. This is followed by the deliberate or accidental introduction of harmful invasive (nonnative) species into ecosystems. Question: What are two direct causes that are specifically related to each of the underlying causes?
• Habitat loss
• Pollution
• Commercial hunting and poaching
• Climate change
• Habitat degradation and fragmentation
• Overfishing
• Sale of exotic pets and decorative plants
• Introduction of nonnative species
• Predator and pest control
Fig. 9-9, p. 198

26. Natural Capital Degradation: Reduction in the Ranges of Four Wildlife Species
Figure 9.10: Natural capital degradation.
These maps reveal the reductions in the ranges of four wildlife species, mostly as the result of severe habitat loss and fragmentation and illegal hunting for some of their valuable body parts. What will happen to these and millions of other species during the next few decades when the human population grows by at least 2 billion—the equivalent of more than 6 times the current U.S. population and almost twice the current population of China—as is projected by scientists? See an animation based on this figure at CengageNOW. Question: Would you support expanding these ranges even though this would reduce the land available for human habitation and farming? Explain. (Data from International Union for the Conservation of Nature and World Wildlife Fund)
Fig. 9-10, p. 199

27. 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
Figure 9.11: These are some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.

28. Case Study: The Kudzu Vine
Imported from Japan in the 1930s
“ The vine that ate the South”
Could there be benefits of kudzu?
Fiber for making paper
Kudzu powder reduces desire for alcohol
Figure 9.12: Kudzu has taken over this abandoned house in the U.S. state of Mississippi. The vine, which can grow 5 centimeters (2 inches) per hour, was deliberately introduced into the United States for erosion control. Digging it up and burning it do not halt its spread. Grazing goats and repeated doses of herbicides can destroy it, but goats and herbicides also destroy other plants, and herbicides can contaminate water supplies. Scientists have found a common fungus that can kill kudzu within a few hours, apparently without harming other plants, but they need to investigate any harmful side effects it may have.

29. Some Accidentally Introduced Species Can Also Disrupt Ecosystems
Argentina fire ant: 1930s
Reduced populations of native ants
Painful stings can kill
Pesticide spraying in 1950s and 1960s worsened conditions
2009: tiny parasitic flies may help control fire ants
Burmese python
Florida Everglades

30. Fight Between a Python and Alligator
Figure 9.13: This huge python and an American alligator were in a life-or-death struggle in the Florida Everglades. After a 10-hour battle the alligator killed the snake by taking it underwater and drowning it. However, in some struggles, these snakes kill and eat the alligators—their only natural predator in the Everglades.
Fig. 9-13, p. 202

31. 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
International treaties
Public education

32. What Can You Do? Controlling Invasive Species
Figure 9.14: Individuals matter.
Here is a list of some 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?
Fig. 9-14, p. 203

33. Other Causes of Species Extinction
Human population growth
Overconsumption
Pollution
Climate change
Pesticides
DDT: Banned in the U.S. in 1972
Bioaccumulation
Biomagnification
Figure 9.15: Bioaccumulation and biomagnification: DDT is a fat-soluble chemical that can accumulate in the fatty tissues of animals. In a food chain or web, the accumulated DDT is biologically magnified in the bodies of animals at each higher trophic level. (Dots in this figure represent DDT.) The concentration of DDT in the fatty tissues of organisms was biomagnified about 10 million times in this food chain in an estuary near Long Island Sound in the U.S. state of New York. If each phytoplankton organism takes up and retains one unit of DDT, a small fish eating thousands of zooplankton (which feed on the phytoplankton) will store thousands of units of DDT in its fatty tissue. Each large fish that eats ten of the smaller fish will ingest and store tens of thousands of units, and each bird (or human) that eats several large fish will ingest hundreds of thousands of units. Question: How does this story demonstrate the value of pollution prevention?

34. Case Study: Where Have All the Honeybees Gone?
Honeybees responsible for 80% of insect-pollinated plants and nearly 1/3 human food
2006: 30% drop in honeybee populations
Dying due to
Pesticides?
Parasites?
Viruses, fungi, bacteria?
Microwave radiation – cell phones?
Bee colony collapse syndrome

35. 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

36. Mountain Gorilla in Rwanda
Figure 9.16: This male mountain gorilla inhabits the bush of the African country of Rwanda. Mountain gorillas feed mostly on the leaves, shoots, and stems of a variety of plants. Only about 700 individuals of this critically endangered species remain in the wild.
Fig. 9-16, p. 205

37. White Rhinoceros Killed by a Poacher
Figure 9.17: This white rhinoceros was killed by a poacher in South Africa solely for its horns. Question: What would you say if you could talk to the person who killed this animal?
Fig. 9-17, p. 205

38. The Rare Rhinoceros Hornbill
Figure 9.B: The rare Rhinoceros hornbill is found in tropical and subtropical forest habitats in parts of Asia. It emits a loud honking squawk and uses its long bill to defend itself from predators such as snakes and monkeys. Its habitat is threatened by agricultural development and logging, and in some areas, the hornbill is threatened by local tribesmen who kill it for food and for its feathers. It is also captured and sold live as part of the illegal wildlife trade.
Fig. 9-B, p. 206

39. Rising Demand for Bush Meat Threatens Some African Species
Bush Meat: Lowland Gorilla
Indigenous people sustained by bush meat
More hunters leading to local extinction of some wild animals
West and Central Africa
Helps spread HIV/AIDS and Ebola from animals to humans
Figure 9.18: Bush meat such as this severed head of an endangered lowland gorilla in the Congo is consumed as a source of protein by local people in parts of West and Central Africa and is sold in national and international marketplaces. You can find bush meat on the menu in Cameroon and the Democratic Republic of the Congo in West Africa as well as in Paris, London, Toronto, New York, and Washington, DC. Poachers are often the suppliers of bush meat. Wealthy patrons of some restaurants regard gorilla meat as a source of status and power. Question: How, if at all, is this different from killing a cow for food?

40. Case Study: A Disturbing Message from the Birds (1)
1/3 of 800 bird species in U.S. are endangered or threatened
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

41. 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

42. Case Study: A Disturbing Message from the Birds (3)
Greatest new threat: Climate change
Environmental indicators
Economic and ecological services

43. Endangered Black-Browed Albatross
Figure 9.19: The IUCN reports that 82% of albatrosses are threatened. The black-browed albatross shown here is endangered because of a drastic reduction in its population, due largely to long-line and trawler fishing fleets whose hooks and nets ensnare and drown these birds when they dive into the water for food.
Fig. 9-19, p. 208

44. 9-4 How Can We Protect Wild Species from Premature Extinction?
Concept 9-4 We can reduce the rising rate of species extinction and help to protect overall biodiversity by establishing and enforcing national environmental laws and international treaties, creating a variety of protected wildlife sanctuaries, and taking precautionary measures to prevent such harm.

45. International Treaties and National Laws Help to Protect Species
1975: Convention on International Trade in Endangered Species (CITES)
Signed by 172 countries
Convention on Biological Diversity (BCD)
Focuses on ecosystems
Ratified by 190 countries (not the U.S.)

46. Endangered Species Act (ESA) 1973 (amended 1982, 1985, 1988)
Identify and protect endangered species in the U.S. and abroad
2010: 1,370 species officially listed
National Marine Fisheries Service for ocean species, U.S. Fish and Wildlife Service for all others
USFWS and NMFS prepare recovery plans
Forbids federal agencies (except Defense) from funding or authorizing projects that jeopardize endangered or threatened species
Incentives for private property owners

47. Why Is ESA NOT a Failure?
Even if only 46 species were removed from endangered list
Species listed only when in serious danger
Takes decades to help endangered species
Conditions for more than half of listed species are stable or improving
2010: spend only 9 cents per American

48. How Can ESA Be Improved? Greatly increase funding
Develop recovery plans more quickly
When a species is first listed, establish the core of its habitat that’s critical for survival
New law needed to focus on sustaining biodiversity and ecosystem health

49. Confiscated Products Made from Endangered Species
Figure 9.20: These confiscated products were made from endangered species. Because of a scarcity of funds and inspectors, probably no more than one-tenth of the illegal wildlife trade in the United States is discovered. The situation is even worse in most other countries.
Fig. 9-20, p. 210

50. We Can Establish Wildlife Refuges and Other Protected Areas
1903: Theodore Roosevelt
Wildlife refuges
Most are wetland sanctuaries
More needed for endangered plants
Could abandoned military lands be used for wildlife habitats?

51. Pelican Island National Wildlife Refuge
Figure 9.21: The Pelican Island National Wildlife Refuge in Florida was America’s first National Wildlife Refuge. It was established in 1903 to help protect the brown pelican (see photo insert) and other birds from extinction. In 2009, the brown pelican was removed from the U.S. endangered species list.
Fig. 9-21a, p. 211

52. Gene Banks, Botanical Gardens, and Wildlife Farms Can Help Protect Species
Gene or seed banks
Preserve genetic material of endangered plants
Botanical gardens and arboreta
Living plants
Farms to raise organisms for commercial sale

53. Zoos and Aquariums Can Protect Some Species
Techniques for preserving endangered terrestrial species
Egg pulling
Captive breeding
Artificial insemination
Embryo transfer
Use of incubators
Cross-fostering
Goal of ultimately releasing/reintroducing populations to the wild
Limited space and funds

54. What Can You Do? Protecting Species
Figure 9.22: Individuals matter.
You can help prevent the extinction of species. Questions: Which two of these actions do you believe are the most important? Why?
Fig. 9-22, p. 213

55. Case Study: Trying to Save the California Condor
Largest North American bird
Nearly extinct
Birds captured and breed in captivity
By 2009, 180 in the wild
Threatened by lead poisoning

56. The Precautionary Principle
Precautionary principle: act to prevent or reduce harm when preliminary evidence indicates acting is needed

57. Three Big Ideas
We are greatly increasing the extinction of wild species by destroying and degrading their habitats, introducing harmful invasive species, and increasing human population growth, pollution, climate change, and overexploitation.
We should avoid causing the extinction of wild species because of the ecological and economic services they provide and because their existence should not depend primarily on their usefulness to us.
We can work to prevent the extinction of species and to protect overall biodiversity by using laws and treaties, protecting wildlife sanctuaries, and making greater use of the precautionary principle.