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Sustaining Biodiversity: The Species Approach
Chapter 9 1967- Declared “endandered” under the US Endangered Species Act 1999- Reduced to “threatened” under the US Endangered Species Act 2007- De-listed Becoming common in coastal GA! Sustaining Biodiversity: The Species Approach
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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?
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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?
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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
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Case Study: Passenger Pigeon
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Why Should We Care About Biodiversity?
Use Value: usefulness in terms of economic and ecological services (many!). Nonuse Value: ·existence value (a.k.a. intrinsic value) ·aesthetic value ·bequest value (for future generations) 1900: 315,000 wild orangutans 2007: <20,000 (losing 2000/yr) Figure 10-3
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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.
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Global Extinction Some animals have become prematurely extinct because of human activities. “The large, the slow, and the tasty” -E.O.Wilson next
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Passenger pigeon Great auk Dodo Dusky seaside sparrow Aepyornis
Figure 11.2 Lost 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 auk Dodo Dusky seaside sparrow Aepyornis (Madagascar) Fig. 11-2, p. 223
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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
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Swallowtail butterfly Humpback chub Golden lion tamarin Siberian tiger
Grizzly bear Kirkland’s warbler Knowlton cactus Florida manatee African elephant Figure 11.3 Endangered 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 dog Swallowtail butterfly Humpback chub Golden lion tamarin Siberian tiger Fig. 11-3, p. 224
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Giant panda Black-footed ferret Whooping crane Northern spotted owl
Blue whale Figure 11.3 Endangered 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 gorilla Florida panther California condor Hawksbill sea turtle Black rhinoceros Fig. 11-3, p. 224
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SPECIES EXTINCTION Some species have characteristics that make them vulnerable to ecological and biological extinction. Next
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Characteristic Examples Low reproductive rate Blue whale, giant panda,
(K-strategist) Specialized niche Narrow distribution a.k.a. endemic species Feeds at high trophic level Fixed migratory patterns Rare Commercially valuable Need large territories Blue whale, giant panda, rhinoceros Everglades kite Many island species, elephant seal, desert pupfish Bengal tiger, bald eagle, grizzly bear Blue whale, whooping crane, sea turtles, many songbirds, esp. neotropical migrants African violet, some orchids Snow leopard, tiger, elephant, rhinoceros, rare plants and birds California condor, grizzly bear, Florida panther Figure 11.4 Natural 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
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Estimating Species Extinction
It is very difficult to catalogue extinction Extinction 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 identified Figure 11-5
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Precautionary Principle
Because it is difficult to know how many species are becoming extinct, many people advocate the precautionary principal. The precautionary principal states that if you are not exactly sure how much damage is being caused, it is best to take preventive measures now until you can be sure. Especially holds true if the potential loss is catastrophic (most people never need their life insurace, but it’s a good idea to have it!)
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SPECIES EXTINCTION Scientists 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
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Percentage Threatened with Extinction Due to Human Activities
34% (51% of freshwater species) Fish 25% Mammals 20% Reptiles Figure 11.5 Endangered 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) Plants 14% Birds 12% Fig. 11-5, p. 225
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SPECIES EXTINCTION Scientists use models to estimate the risk of particular species becoming extinct or endangered. Next
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Number of years until one million
of species existing Effects of a 0.1% extinction rate 5,000 extinct per year 5 million 14 million 14,000 extinct per year 50 million 50,000 extinct per year 100 million Figure 11.6 Natural capital degradation: effects of a 0.1% extinction rate. 100,000 extinct per year Number of years until one million species are extinct Fig. 11-6, p. 226
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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).
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Biophilia vs Biophobia E.O. Wilson
Biophilia- literally, “love of life”, meaning love of the natural world. Connotative meaning: we are one with, part of, and totally connected to all of life on earth. Biophobia- Fear of the natural world. Connotative meaning: Nature is the enemy, to be dominated and exploited.
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HABITAT LOSS, DEGRADATION, AND FRAGMENTATION
Conservation biologists summarize the most important causes of premature extinction as “CHIPPO”: Climate Change Habitat destruction, degradation, and fragmentation Invasive species Population growth Pollution Overharvest
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HABITAT LOSS, DEGRADATION, AND FRAGMENTATION
The greatest threat to species is the loss, degradation, and fragmentation of habitat. Next
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Causes of Depletion and Premature Extinction of Wild Species
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 Figure 11.7 Natural 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. • Climate change • Sale of exotic pets and decorative plants • Overfishing • Introduction of nonnative species • Predator and pest control Fig. 9-10, p. 193
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HABITAT LOSS, DEGRADATION, AND FRAGMENTATION
Reduction in ranges of four wildlife species, mostly due to habitat loss and overharvest. NEXT
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Indian Tiger Range 100 years ago Range today (about 2,300 left)
Figure 11.8 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? (Data from International Union for the Conservation of Nature and World Wildlife Fund) Range 100 years ago Range today (about 2,300 left) Fig. 11-8a, p. 230
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Black Rhino Range in 1700 Range today (about 3,600 left)
Figure 11.8 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? (Data from International Union for the Conservation of Nature and World Wildlife Fund) Range in 1700 Range today (about 3,600 left) Fig. 11-8b, p. 230
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African Elephant Probable range 1600 Range today Fig. 11-8c, p. 230
Figure 11.8 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? (Data from International Union for the Conservation of Nature and World Wildlife Fund) Probable range 1600 Range today Fig. 11-8c, p. 230
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Asian or Indian Elephant
Figure 11.8 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? (Data from International Union for the Conservation of Nature and World Wildlife Fund) Former range Range today (34,000–54,000 left) Fig. 11-8d, p. 230
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Case Study: A Disturbing Message from the Birds
70% of bird species are declining in number Especially true of migratory bird species A.K.A. “Neotropical migrants” Next
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Golden-cheeked warbler
Cerulean warbler Sprague’s pipit Bichnell’s thrush Black-capped vireo Golden-cheeked warbler Figure 11.10 Threatened 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 jay California gnatcatcher Kirtland’s warbler Henslow’s sparrow Bachman’s warbler Fig , p. 232
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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) 400 200 1 Fig. 11-9, p. 231
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Case Study: A Disturbing Message from the Birds
Worldwide, 70% of the world’s 10,000 bird species are declining The majority of the world’s bird species are found in South America. Threatened with habitat loss and invasive species. NEXT
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INVASIVE SPECIES Many 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
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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
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KUDZU! Figure 11-A
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INVASIVE SPECIES Many invasive species have been introduced intentionally. NEXT
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Deliberately Introduced Species
Purple loosestrife European starling African honeybee (“Killer bee”) Nutria Salt cedar (Tamarisk) Figure 11.11 Threats 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 beetle European wild boar (Feral pig) Water hyacinth Hydrilla Fig a, p. 234
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INVASIVE SPECIES Many invasive species have been introduced unintentionally. NEXT
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Accidentally Introduced Species
Sea lamprey (attached to lake trout) Argentina fire ant Brown tree snake Eurasian ruffe Common pigeon (Rock dove) Figure 11.11 Threats 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 termite Zebra mussel Asian long-horned beetle Asian tiger mosquito Gypsy moth larvae Fig b, p. 234
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INVASIVE SPECIES The Argentina fire ant was introduced to Mobile, Alabama in 1932 from South America. Most probably from ships. No natural predators in North America. Figure 11-12
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Fire Ants! Figure 11-12
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INVASIVE SPECIES Prevention 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
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• 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 11.14 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? Which of these actions do you plan to take? Fig , p. 236
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Ecosystems Vulnerable
Characteristics of Successful Invader Species Characteristics of Ecosystems Vulnerable to Invader Species • High reproductive rate, short generation time (r-selected species) • Pioneer species • Long lived • High dispersal rate • Release growth-inhibiting chemicals into soil • Generalists • High genetic variability • Climate similar to habitat of invader • Absence of predators on invading species • Early successional systems • Low diversity of native species • Absence of fire • Disturbed by human activities Figure 11.13 Threats to natural capital: some general characteristics of successful invasive species and ecosystems vulnerable to invading species. Fig , p. 236
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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.
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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
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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 11.15 Natural 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 ppm DDT in water ppm, Fig , p. 237
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OVEREXPLOITATION Killing predators and pests that bother us or cause economic losses threatens some species with premature extinction. Some protected species are killed for their valuable parts or are sold live to collectors. Legal and illegal trade in wildlife species used as pets or for decorative purposes threatens some species with extinction.
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OVEREXPLOITATION: Poaching
The illegal killing of wildlife for food or profit is called poaching. Rhinoceros are often killed for their horns and sold illegally on the black market for decorative and medicinal purposes. Figure 11-16
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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
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Why is Demand for Bushmeat Rising in Africa?
Human population growth Making $ supplying restaurants with exotic meat Roads: Accessibility to remote areas European companies overfishing coastal African waters This has also contributed to Somalian piracy Figure 11-17
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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 including the USA, lists 900 species that cannot be commercially traded.
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INTERNATIONAL TREATIES
Convention on Biodiversity- Goals: reverse delcines in biodiversity & share the benefits of genetic resources Problems: Lack of enforcement Lack of severe penalties Implementation delays U.S. has not ratified
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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
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Figure 11-19
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For every live and exotic animal captured & sold in the pet market, _______ are killed during capture or die in transit. 50
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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 11.21 Individuals 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
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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. Landowners could destroy some habitat under special agreements with the US Fish & Wildlife Service. ESA makes it illegal for Americans to engage in commerce associated with, or hunt / kill / collect endangered or threatened species.
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Case Study: The U.S. Endangered Species Act
Unsuccessful attempts have been made since 1973 to change the ESA: Make protection of endangered species voluntary on private land Make it harder and more expensive to list a species Eliminate the need to designate critical habitats Allow the Secretary of the Interior to permanently exempt landowners
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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. Next
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3 Southern Appalachians 4 Death Valley 5 Southern California
Top Six Hot Spots 1 Hawaii 2 San Francisco Bay area 3 Southern Appalachians 4 Death Valley 5 Southern California 6 Florida Panhandle Figure 11.18 Threatened 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 species Low Moderate High Fig , p. 241
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PROTECTING WILD SPECIES: THE SANCTUARY APPROACH
Blue Goose, symbol of all US NWR’s NWR’s: Protect habitat for migratory waterfowl. PROTECTING WILD SPECIES: THE SANCTUARY APPROACH
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PROTECTING WILD SPECIES: THE SANCTUARY APPROACH
The U.S. has set aside 544 National Wildlife Refuges, mostly for migratory waterfowl, but many refuges are suffering from environmental degradation. Okefenokee is an NWR Pelican Island was the nation’s first wildlife refuge. Figure 11-20
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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.
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Seed Banks Svalbard Global Seed Vault
Secure seedbank located on the Norwegian island of Spitsbergen since January 2008. The seed vault is an attempt to provide insurance against the loss of seeds in genebanks, as well as a refuge for seeds in the case of large-scale regional or global crises. Currently about 360,000 differernt varieties of seed are stored there.
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Svalbard Global Seed Vault
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Svalbard Global Seed Vault
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Svalbard Global Seed Vault
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Seed Banks Svalbard Global Seed Vault
Spitsbergen was considered ideal because it lacked tectonic activity and had permafrost, which aids preservation. Its being 130 metres (430 ft) above sea level will keep the site dry even if the ice caps melt.[9] Locally mined coal provides power for refrigeration units that further cool the seeds to the internationally recommended standard of −18 °C (−0.4 °F).[10] If the equipment fails, at least several weeks will elapse before the facility rises to the surrounding sandstone bedrock's temperature of −3 °C (27 °F) Wikipedia
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Svalbard Global Seed Vault
Construction of the seed vault, which cost approximately NOK 45 million (US$9 million), was funded entirely by the Government of Norway. Storage of seeds in the seed vault is free-of-charge. Primary funding for the Trust comes from organisations, such as the Bill & Melinda Gates Foundation, and from various governments worldwide.[7]
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PROTECTING WILD SPECIES: THE SANCTUARY APPROACH
Zoos and aquariums can also help protect endangered animal species by preserving some individuals with the long-term goal of reintroduction, but suffer from lack of space and money. Avoiding genetic bottlenecks: Need a minimum of 100 to 500 individuals to sustain genetic diversity via captive breeding
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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).
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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
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