Presentation on theme: "Sustaining Biodiversity: The Species Approach"— Presentation transcript:
1 Sustaining Biodiversity: The Species Approach Chapter 9Sustaining Biodiversity: The Species Approach
2 Chapter Overview Questions How do biologists estimate extinction rates, and how do human activities affect these rates?Why should we care about protecting wild species?Which human activities endanger wildlife?
3 Chapter Overview Questions How can we help prevent premature extinction of species?What is reconciliation ecology, and how can it help prevent premature extinction of species?
4 Core Case Study: The Passenger Pigeon - Gone Forever Once the most numerous bird on earth.In 1858, Passenger Pigeon hunting became a big business.By 1900 they became extinct from over-harvest and habitat loss.Figure 11-1
6 Why Should We Care About Biodiversity? Use Value: usefulness in terms of economic and ecological services.Nonuse Value: ·existence value(a.k.a. intrinsic value)·aesthetic value·bequest value(for future generations)1900: 315,000 wild orangutans2007: <20,000 (losing 2000/yr)Figure 10-3
7 SPECIES EXTINCTION Species can become extinct: Locally: A species is no longer found in an area it once inhabited but is still found elsewhere in the world.Ecologically: Occurs when so few members of a species are left they no longer play its ecological role.Biologically: Species is no longer found on the earth.
8 Global ExtinctionSome animals have become prematurely extinct because of human activities.“The large, the slow, and the tasty”-E.O.Wilsonnext
9 Passenger pigeon Great auk Dodo Dusky seaside sparrow Aepyornis Figure 11.2Lost natural capital: some animal species that have become prematurely extinct largely because of human activities, mostly habitat destruction and overhunting. The Great Auk became extinct in 1844 from overhunting because of its willingness to march up the boardwalks to ships. QUESTION: Why do you think birds top this list?Great aukDodoDusky seaside sparrowAepyornis(Madagascar)Fig. 11-2, p. 223
10 Endangered and Threatened Species: Ecological Smoke Alarms Endangered species: so few individual survivors that it could soon become extinct.Threatened species: still abundant in its natural range but is likely to become endangered in the near future (high current losses)next
11 Swallowtail butterfly Humpback chub Golden lion tamarin Siberian tiger Grizzly bearKirkland’s warblerKnowlton cactusFlorida manateeAfrican elephantFigure 11.3Endangered natural capital: species that are endangered or threatened with premature extinction largely because of human activities. Almost 30,000 of the world’s species and 1,260 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.Utah prairie dogSwallowtail butterflyHumpback chubGolden lion tamarinSiberian tigerFig. 11-3, p. 224
12 Giant panda Black-footed ferret Whooping crane Northern spotted owl Blue whaleFigure 11.3Endangered natural capital: species that are endangered or threatened with premature extinction largely because of human activities. Almost 30,000 of the world’s species and 1,260 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.Mountain gorillaFlorida pantherCalifornia condorHawksbill sea turtleBlack rhinocerosFig. 11-3, p. 224
13 SPECIES EXTINCTIONSome species have characteristics that make them vulnerable to ecological and biological extinction.Next
14 Characteristic Examples Low reproductive rate (K-strategist) Specialized nicheNarrow distributionFeeds at high trophic levelFixed migratory patternsRareCommercially valuableLarge territoriesBlue whale, giant panda,rhinocerosEverglades kiteMany island species,elephant seal, desert pupfishBengal tiger, bald eagle,grizzly bearBlue whale, whooping crane,sea turtles, many songbirdsAfrican violet, some orchidsSnow leopard, tiger,elephant, rhinoceros,rare plants and birdsCalifornia condor, grizzlybear, Florida pantherFigure 11.4Natural capital loss and degradation: 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?Fig. 11-4, p. 225
15 Estimating Species Extinction It is very difficult to catalogue extinctionExtinction takes a long time to happen and is difficult to measure (need long term pop. data)We have only identified 1.7 million of the world’s 4 to 100 million species (likely about 14 million)We know little about most of the species that have been identifiedFigure 11-5
16 SPECIES EXTINCTIONScientists use measurements and models to estimate extinction rates.The International Union for the Conservation of Nature and Natural Resources (IUCN) publishes an annual Red List, listing the world’s threatened species.The 2004 Red List contains 15,589 species at risk for extinction.Figure 11-5
17 SPECIES EXTINCTIONPercentage of various species types threatened with premature extinction from human activities.Next
18 34% (51% of freshwater species) Fish 25%Mammals20%ReptilesFigure 11.5Endangered natural capital: percentage of various types of species threatened with premature extinction because of human activities. QUESTION: Why do you think fish top this list? (Data from World Conservation Union, Conservation International, and World Wildlife Fund)Plants14%Birds12%Fig. 11-5, p. 225
19 SPECIES EXTINCTIONScientists use models to estimate the risk of particular species becoming extinct or endangered.Next
20 Number of years until one million of speciesexistingEffects of a 0.1% extinction rate5,000 extinct per year5 million14 million14,000 extinct per year50 million50,000 extinct per year100 millionFigure 11.6Natural capital degradation: effects of a 0.1% extinction rate.100,000 extinct per yearNumber of years until one millionspecies are extinctFig. 11-6, p. 226
21 IMPORTANCE OF WILD SPECIES We should not cause the premature extinction of species because of the economic and ecological services they provide.Some believe that each wild species has an inherent right to exist.Some people distinguish between the survival rights among various types of species (plants vs. animals).
22 HABITAT LOSS, DEGRADATION, AND FRAGMENTATION Conservation biologists summarize the most important causes of premature extinction as “HIPPO”:Habitat destruction, degradation, and fragmentationInvasive speciesPopulation growthPollutionClimate ChangeOverharvest
23 HABITAT LOSS, DEGRADATION, AND FRAGMENTATION The greatest threat to a species is the loss, degradation, and fragmentation of where it lives.Next
24 BASIC CAUSES • No environmental accounting Habitatloss Overfishing PollutionHabitat degradationand fragmentationCommercial hunting and poachingClimate changeIntroducingnonnative speciesSale of exotic pets and decorative plantsPredator and pest controlSecondary Causes• Population growth• Rising resource use• Poverty• No environmental accountingFigure 11.7Natural capital degradation: underlying and direct causes of depletion and premature extinction of wild species. The major direct cause of wildlife depletion and premature extinction is habitat loss, degradation, and fragmentation. This is followed by the deliberate or accidental introduction of harmful invasive (nonnative) species into ecosystems.BASIC CAUSESFig. 11-7, p. 229
25 HABITAT LOSS, DEGRADATION, AND FRAGMENTATION Reduction in ranges of four wildlife species, mostly due to habitat loss and overharvest.NEXT
26 Indian Tiger Range 100 years ago Range today (about 2,300 left) Figure 11.8Natural 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? (Data from International Union for the Conservation of Nature and World Wildlife Fund)Range 100 years agoRange today(about 2,300 left)Fig. 11-8a, p. 230
27 Black Rhino Range in 1700 Range today (about 3,600 left) Figure 11.8Natural 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? (Data from International Union for the Conservation of Nature and World Wildlife Fund)Range in 1700Range today(about 3,600 left)Fig. 11-8b, p. 230
28 African Elephant Probable range 1600 Range today Fig. 11-8c, p. 230 Figure 11.8Natural 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? (Data from International Union for the Conservation of Nature and World Wildlife Fund)Probable range 1600Range todayFig. 11-8c, p. 230
29 Asian or Indian Elephant Figure 11.8Natural 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? (Data from International Union for the Conservation of Nature and World Wildlife Fund)Former rangeRange today(34,000–54,000 left)Fig. 11-8d, p. 230
30 Case Study: A Disturbing Message from the Birds Human activities are causing serious declines in the populations of many bird species.Especially true of migratory bird species A.K.A. “Neotropical migrants”Next
31 Golden-cheeked warbler Cerulean warblerSprague’s pipitBichnell’s thrushBlack-capped vireoGolden-cheeked warblerFigure 11.10Threatened natural capital: the 10 most threatened species of U.S. songbirds, according to a 2002 study by the National Audubon Society. 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 from human activities during this century. (Data from National Audubon Society)Florida scrub jayCalifornia gnatcatcherKirtland’s warblerHenslow’s sparrowBachman’s warblerFig , p. 232
32 Case Study: A Disturbing Message from the Birds Worldwide, 70% of the world’s 10,000 bird species are decliningThe majority of the world’s bird species are found in South America.Threatened with habitat loss and invasive species.NEXT
33 Number of bird species 609 400 200 1 Fig. 11-9, p. 231 Figure 11.9 Natural capital: distribution of bird species in North America and Latin America. (Data from the Nature Conservancy, Conservation International, World Wildlife Fund, and Environment Canada)4002001Fig. 11-9, p. 231
34 INVASIVE SPECIESMany nonnative species provide us with food, medicine, and other benefits but a few can wipe out native species, disrupt ecosystems, and cause large economic losses.Kudzu vine was introduced in the southeastern U.S. to control erosion. It has taken over native species habitats.Figure 11-A
35 USES FOR KUDZU Almost every part of the plant is edible. Provides a starch used in beverages and gourmet confections.Provides herbal remedies for several diseases.It is a source of fiber for paper that could replace use of trees.Figure 11-A
37 INVASIVE SPECIESMany invasive species have been introduced intentionally.Figure 11-11
38 Deliberately Introduced Species Purple loosestrifeEuropean starlingAfrican honeybee(“Killer bee”)NutriaSalt cedar(Tamarisk)Figure 11.11Threats to natural capital: some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.Marine toad(Giant toad)Japanese beetleEuropean wild boar(Feral pig)Water hyacinthHydrillaFig a, p. 234
39 INVASIVE SPECIESMany invasive species have been introduced unintentionally.Figure 11-11
40 Accidentally Introduced Species Sea lamprey(attached to lake trout)Argentina fire antBrown tree snakeEurasian ruffeCommon pigeon(Rock dove)Figure 11.11Threats to natural capital: some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.Formosan termiteZebra musselAsian long-horned beetleAsian tiger mosquitoGypsy moth larvaeFig b, p. 234
41 Figure 11.11Threats to natural capital: some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.Fig , p. 234
42 INVASIVE SPECIESThe Argentina fire ant was introduced to Mobile, Alabama in 1932 from South America.Most probably from ships.No natural predators.Figure 11-12
44 INVASIVE SPECIESPrevention is the best way to reduce threats from invasive species, because once they arrive it is almost impossible to slow their spread.Figure 11-13
45 • Do not allow wild animals to escape. What Can You Do?Invasive Species• Do not allow wild animals to escape.• Do not spread wild plants to other areas.• Do not dump the contents of an aquarium into waterways, wetlands, or storm drains.• When camping use wood near your campsite instead of bringing firewood from somewhere else.• Do not dump unused bait into the water.• After dogs visit woods or the water brush them before taking them home.• After each use clean your vehicle, mountain bike, surfboard, kayaks, canoes, boats, tent, hiking boots, and other gear before heading for home.• Empty all water from canoes, kayaks, dive gear, and other outdoor equipment before heading home.• Plant a variety of trees, shrubs, and other plants in your yard to reduce losses from invasive species.• Do not buy plants from overseas or swap them with others using the Internet.Figure 11.14Individuals 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? Which of these actions do you plan to take?Fig , p. 236
46 Ecosystems Vulnerable Characteristics ofSuccessfulInvader SpeciesCharacteristics ofEcosystems Vulnerableto Invader Species• High reproductive rate,short generation time(r-selected species)• Pioneer species• Long lived• High dispersal rate• Release growth-inhibitingchemicals into soil• Generalists• High genetic variability• Climate similar to habitat of invader• Absence of predators on invading species• Early successionalsystems• Low diversity of native species• Absence of fire• Disturbed by human activitiesFigure 11.13Threats to natural capital: some general characteristics of successful invasive species and ecosystems vulnerable to invading species.Fig , p. 236
47 POPULATION GROWTH, POLLUTION, AND CLIMATE CHANGE Population growth, affluenza, and pollution have promoted the premature extinction of some species.Projected climate change threatens a number of species with premature extinction.
48 Pollution Each year pesticides: Kill about 1/5th of the U.S. honeybee colonies.67 million birds.6 -14 million fish.Threaten 1/5th of the U.S.’s endangered and threatened species.Example of biomagnification of DDT in an aquatic food chain.Note: Toxins bioaccumulate in the tissues of an individual organism, but biomagnify through a food chain.NEXT
49 DDT in fish-eating birds (ospreys) 25 ppmDDT in large fish (needle fish)2 ppmDDT in small fish (minnows)0.5 ppmFigure 11.15Natural capital degradation: 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 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, and arrows show small losses of DDT through respiration and excretion.DDT in zooplankton 0.04 ppmDDT in water ppm,Fig , p. 237
50 OVEREXPLOITATIONSome protected species are killed for their valuable parts or are sold live to collectors.Killing predators and pests that bother us or cause economic losses threatens some species with premature extinction.Legal and illegal trade in wildlife species used as pets or for decorative purposes threatens some species with extinction.
51 OVEREXPLOITATIONRhinoceros are often killed for their horns and sold illegally on the black market for decorative and medicinal purposes.Figure 11-16
52 Case Study: Rising Demand for Bushmeat in Africa Bushmeat hunting has caused the local extinction of many animals in West Africa.Can spread disease such as HIV/AIDS and ebola virus.Figure 11-17
53 Why is Demand for Bushmeat Rising in Africa? Human population growthMaking $ supplying restaurants with exotic meatRoads: Accessibility to remote areasEuropean companies overfishing coastal African watersFigure 11-17
54 PROTECTING WILD SPECIES: LEGAL AND ECONOMIC APPROACHES International treaties have helped reduce the international trade of endangered and threatened species, but enforcement is difficult.One of the most powerful is the 1975 Convention on International Trade of Endangered Species (CITES).Signed by 169 countries, lists 900 species that cannot be commercially traded.
55 INTERNATIONAL TREATIES Convention on Biodiversity- Goals: reverse delcines in biodiversity & share the benefits of genetic resourcesProblems:Lack of enforcementLack of severe penaltiesImplementation delaysU.S. has not ratified
56 Case Study: The U.S. Endangered Species Act One of the world’s most far-reaching and controversial environmental laws is the 1973 U.S. Endangered Species Act (ESA).ESA forbids federal agencies (besides defense department) to carry out / fund projects that would jeopardize an endangered species.ESA makes it illegal for Americans to engage in commerce associated with or hunt / kill / collect endangered or threatened species.
57 Case Study: The U.S. Endangered Species Act Attempts have been made since to change the ESA:Make protection of endangered species voluntary on private landMake it harder and more expensive to list a speciesEliminate the need to designate critical habitatsAllow the Secretary of the Interior to permanatly exempt landowners
58 Case Study: The U.S. Endangered Species Act Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S.Figure 11-18
59 3 Southern Appalachians 4 Death Valley 5 Southern California Top Six Hot Spots1 Hawaii2 San Francisco Bay area3 Southern Appalachians4 Death Valley5 Southern California6 Florida PanhandleFigure 11.18Threatened natural capital: biodiversity hot spots in the United States. The shaded areas contain the largest concentrations of rare and potentially endangered species. Compare these areas with those on the map of the human ecological footprint in North America shown in Figure 4 on pp. S14–S15 in Supplement 4. (Data from State Natural Heritage Programs, the Nature Conservancy, and Association for Biodiversity Information)Concentration of rare speciesLowModerateHighFig , p. 241
60 Because of scarcity of inspectors, probably no more than 1/10th of the illegal wildlife trade in the U.S. is discovered.Figure 11-19
61 For every live and exotic animal captured & sold in the pet market, _______ are killed during capture or die in transit.50
62 What Can You Do? Protecting Species • Do not buy furs, ivory products, and other materials made from endangered or threatened animal species.• Do not buy wood and paper products produced by cutting remaining old-growth forests in the tropics.• Do not buy birds, snakes, turtles, tropical fish, and other animals that are taken from the wild.• Do not buy orchids, cacti, and other plants that are taken from the wild.• Spread the word. Talk to your friends and relatives about this problem and what they can do about it.Figure 11.21Individuals matter: ways to help premature extinction of species. QUESTIONS: Which two of these actions do you think are the most important? Which of these actions do you plan to take?Fig , p. 246
63 PROTECTING WILD SPECIES: THE SANCTUARY APPROACH The U.S. has set aside 544 federal refuges for wildlife, but many refuges are suffering from environmental degradation.Pelican Island was the nation’s first wildlife refuge.Figure 11-20
64 PROTECTING WILD SPECIES: THE SANCTUARY APPROACH Gene banks, seed banks, botanical gardens and using farms to raise threatened species can help prevent extinction, but these options lack funding and storage space.Zoos and aquariums can help protect endangered animal species by preserving some individuals with the long-term goal of reintroduction, but suffer from lack of space and money.
65 RECONCILIATION ECOLOGY Reconciliation ecology involves finding ways to share places we dominate with other species.Replacing monoculture grasses with native species.Maintaining habitats for insect eating bats can keep down unwanted insects.Reduction and elimination of pesticides to protect non-target organisms (such as vital insect pollinators).
66 Using Reconciliation Ecology to Protect Bluebirds Putting up bluebird boxes with holes too small for (nonnative) competitors in areas where trees have been cut down have helped reestablish populations.Figure 11-B
67 Updates OnlineThe latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at to access InfoTrac articles.InfoTrac: Domestic cats serve as add-on predators. Paducah Sun (Paducah, KY), July 26, 2006.InfoTrac: Invasion of the habitat snatchers. Wichita Eagle, August 6, 2006.InfoTrac: Group pulls for native Denali plants. Anchorage Daily News, June 26, 2006.Union of Concerned Scientists: Invasive SpeciesPBS: Strange Days on Planet EarthUSGS: Nonindigenous Aquatic Species