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Sustaining Biodiversity: The Species Approach

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

9 Conservative estimates of extinction = 0.01-0.1%
Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up (2) Conservative estimates of extinction = % Growth of human population will increase this loss to 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 9.3 Effects 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 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. Grizzly bear Kirkland’s warbler Knowlton cactus Florida manatee African elephant Utah prairie dog Swallowtail butterfly Humpback chub Golden lion tamarin Siberian tiger Giant panda Black-footed ferret Whooping crane Northern spotted owl Blue whale Mountain gorilla Florida panther California condor Hawksbill sea turtle Black rhinoceros

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

15 Figure 9.6 Endangered 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 9.7 Natural 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. 8 Natural capital: nature’s pharmacy
Figure 9.8 Natural 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 9.9 Many 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

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)
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 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.

30 Tropical Biologist Bill Laurance, et al.
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?

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
One in every eight bird species (12%) is threatened with extinction. Three-fourths live in forests. Numbers Location Reason(s) 75% of birds species Sumatra’s lowland forests Lumber and palm plantations, used for biofuels 115 bird species Brazil Burning/clearing of rainforests for farms and ranches; 93% loss of Atlantic coastal rainforest; clearing of savannah-like cerrado for soybean plantations 30% of bird species, 70% of grassland species North America Habitat loss and fragmentation of breeding habitat; replaced by roads and other developments. 28% of species Worldwide Introduction of non-native bird-eating species 52 of 388 parrot species Pet trade 23 Seabirds Bycatch from commercial fishing; pollution 40% of waterbirds Loss of wetlands

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 9.12 Distribution 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 Golden-cheeked warbler California gnatcatcher
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) Cerulean warbler Sprague’s pipit Bichnell’s thrush Black-capped vireo Golden-cheeked warbler California gnatcatcher Kirtland's warbler Florida scrub jay Henslow's sparrow Bachman's warbler

37 Vultures poisoned from diclofenac in cow carcasses
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 9.16 The 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 9.17 Some 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 9.18 Individuals 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 Figure 9.19 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 can be biologically magnified in the bodies of animals at each higher trophic level. 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 from the water 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 10 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. Dots represent DDT. Question: How does this story demonstrate the value of pollution prevention? DDT in zooplankton 0.04 ppm DDT in water ppm, or 3 ppt

51 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

52 Case Study: Polar Bears and Global Warming
Environmental impact on polar bears Less summer sea ice PCBs and DDT Can adversely affect their development, behavior, and reproduction. IUCN 2006 Study: Population projected to decline by %, and may be found only in zoos by end of century. 2007 listed as threatened species 2008 listed as threatened species under US ESA.

53 Figure 9.20 Polar bear with seal prey on floating ice in Svalbard, Norway. Polar bears in the Arctic are likely to become extinct sometime during this century because global warming is melting the floating sea ice on which they hunt seals.

54 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 When commercially valuable species become endangered, black market prices soar. Prevention: research and education

55 Figure 9.21 White rhinoceros killed by a poacher for its horn in South Africa. Question: What would you say if you could talk to the poacher of this animal?

56 The hyacinth macaw, Anodorhynchus hyacinthinus, may be worth $ to an exotic bird collector, but worth $ in tourist revenues left in the wild.

57 Individuals Matter: Jane Goodall
Primatologist and anthropologist 45 years understanding and protecting chimpanzees Chimps have tool-making skills

58 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 US Agency for International Development, trying to introduce alternatives in some areas. Fish farms Breeding large rodents, like cane rats.

59 Figure 9.22 Bush meat, such as this severed head of a lowland gorilla in the Congo, is consumed as a source of protein by local people in parts of West Africa and sold in the national and international marketplace. You can find bush meat on the menu in Cameroon and the Congo in West Africa as well as in Paris, London, Toronto, New York, and Washington, D.C. It is often supplied by poaching. 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?

60 9-4 How Can We Protect Wild Species from Premature Extinction? (1)
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.

61 9-4 How Can We Protect Wild Species from Premature Extinction? (2)
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.

62 International Treaties 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.)

63 Case Study: The U.S. Endangered Species Act (1)
Endangered Species Act (ESA): 1973 and later amended in 1982, 1983, and 1985 Identify and protect endangered species in the U.S. and abroad Hot Spots Habitat Conservation Plan (HCP) colony

64 Case Study: The U.S. Endangered Species Act (2)
Mixed reviews of the ESA Weaken it Repeal it Modify it Strengthen it Simplify it Streamline it

65 Confiscated Products Made from Endangered Species

66 Science Focus: Accomplishments of the Endangered Species Act (1)
Species listed only when serious danger of extinction Takes decades for most species to become endangered or extinct More than half of the species listed are stable or improving Budget has been small

67 Science Focus: Accomplishments of the Endangered Species Act (2)
Suggested changes to ESA Increase the budget Develop recovery plans more quickly Establish a core of the endangered organism’s survival habitat

68 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?

69 Botanical gardens and arboreta
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

70 Zoos and Aquariums Can Protect Some Species (1)
Techniques for preserving endangered terrestrial species Egg pulling Captive breeding Artificial insemination Embryo transfer Use of incubators Cross-fostering

71 Zoos and Aquariums Can Protect Some Species (2)
Limited space and funds Critics say these facilities are prisons for the organisms

72 What Can You Do? Protecting Species

73 Case Study: Trying to Save the California Condor
Largest North American bird Nearly extinct Birds captured and breed in captivity By 2007, 135 released into the wild Threatened by lead poisoning

74 The Precautionary Principle
Species: primary components of biodiversity Preservation of species Preservation of ecosystems

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