Sustaining Biodiversity: The Species Approach Chapter 9
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Sustaining Biodiversity: The Species Approach
Chapter 9
Core Case Study: The Passenger Pigeon: Gone Forever
Passenger pigeon hunted to extinction by 1900
Commercial hunters used a "stool pigeon”
Archeological record shows five mass extinctions
Human activities: hastening more extinctions?
Passenger Pigeon
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.
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
Extinctions Are Natural but Sometimes They Increase Sharply
Background extinction
Extinction rate
Mass extinction: causes?
Levels of species extinction • Local extinction • Ecological extinction • Biological extinction
Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up (1)
Premature extinctions due to • Habitat destruction • Overhunting
Conservative estimates of extinction = 0.01-1.0% • 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
Speciation crisis
Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up (2)
Animal Species Prematurely Extinct Due to Human Activities
Fig. 9-2, p. 185
Passenger pigeon
Great auk Dodo Golden toad Aepyornis (Madagascar)
Effects of a 0.1% Extinction Rate
Fig. 9-3, p. 186
Number of species existing Effects of a 0.1% extinction rate
5 million 5,000 extinct per year
14 million 14,000 extinct per year
50 million 50,000 extinct per year
100 million 100,000 extinct per year
Number of years until one million species are extinct
200 0 50 100 150
Endangered and Threatened Species Are Ecological Smoke Alarms
Endangered species
Threatened species, vulnerable species • Characteristics of such species
Endangered Natural Capital: Species Threatened with Premature Extinction
Fig. 9-4, p. 187
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
Characteristics of Species That Are Prone to Ecological and Biological Extinction
Fig. 9-5, p. 188
Low reproductive rate (K-strategist)
Blue whale, giant panda, rhinoceros
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
Characteristic Examples
Fig. 9-5, p. 188 Stepped Art
Fixed migratory patterns
Blue whale, whooping crane, sea turtle
Feeds at high trophic level
Bengal tiger, bald eagle, grizzly bear
Narrow distribution
Elephant seal, desert pupfish
Commercially valuable
Snow leopard, tiger, elephant, rhinoceros, rare plants and birds
Low reproductive rate (K-strategist)
Blue whale, giant panda, rhinoceros
Characteristic Examples
Rare African violet, some orchids
Large territories California condor, grizzly bear, Florida panther
Specialized niche
Blue whale, giant panda, Everglades kite
Percentage of Various Species Threatened with Premature Extinction
Fig. 9-6, p. 189
Fishes 34% (51% of freshwater species)
Amphibians 32%
Mammals 25%
Reptiles 20%
Plants 14%
Birds 12%
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
Use species–area relationship
Mathematical models
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.
Species Are a Vital Part of the Earth’s Natural Capital
Instrumental value • Use value
• Ecotourism: wildlife tourism • Genetic information
• Nonuse value • Existence value • Aesthetic value • Bequest value
Ecological value
Natural Capital Degradation: Endangered Orangutans in a Tropical Forest
Natural Capital: Nature’s Pharmacy
Fig. 9-8, p. 190
Pacific yew Taxus brevifolia, Pacific Northwest Ovarian cancer
Rosy periwinkle Cathranthus roseus, Madagascar Hodgkin's disease, lymphocytic leukemia
Rauvolfia Rauvolfia sepentina, Southeast Asia Anxiety, high blood pressure
Neem tree Azadirachta indica, India Treatment of many diseases, insecticide, spermicide
Foxglove Digitalis purpurea, Europe Digitalis for heart failure
Cinchona Cinchona ledogeriana, South America Quinine for malaria treatment
Endangered Scarlet Macaw is a Source of Beauty and Pleasure
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?
Are We Ethically Obligated to Prevent Premature Extinction?
Intrinsic value: existence value
Edward O. Wilson: biophilia phenomenon
Biophobia
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
ABC Video: Bachelor pad at the zoo
ABC Video: Hsing Hsing dies
ABC Video: Penguin rescue
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.
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
Causes of Depletion and Premature Extinction of World Species
Fig. 9-10, p. 193
NATURAL CAPITAL DEGRADATION
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
• Introduction of nonnative species
• Overfishing • Predator and pest control
Causes of Depletion and Premature Extinction of Wild Species
Natural Capital Degradation: Reduction in the Ranges of Four Wildlife Species
Fig. 9-11a, p. 194
Fig. 9-11a, p. 194
Indian Tiger
Range 100 years ago
Range today
Fig. 9-11b, p. 194
Fig. 9-11b, p. 194
Black Rhino
Range in 1700
Range today
Fig. 9-11c, p. 194
Fig. 9-11c, p. 194
African Elephant
Probable range 1600 Range today
Fig. 9-11d, p. 194
Fig. 9-11d, p. 194
Asian or Indian Elephant
Former range
Range today
Fig. 9-11, p. 194 Stepped Art
Indian Tiger
Range 100 years ago Range today
Black Rhino
Range in 1700 Range today
African Elephant
Probable range 1600 Range today
Asian or Indian Elephant
Former range Range today
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?
Case Study: A Disturbing Message from the Birds (1)
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
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
Case Study: A Disturbing Message from the Birds (3)
Greatest new threat: Climate change
Environmental indicators
Economic and ecological services
Distribution of Bird Species in North America and Latin America
Fig. 9-12, p. 195
Number of bird species
609
400
200
1
The Ten Most Threatened Song Birds in the United States
Fig. 9-13, p. 196
Cerulean warbler Sprague’s pipit Bichnell’s thrush Black-capped vireo
Golden-cheeked warbler
Florida scrub jay California gnatcatcher
Kirtland's warbler Henslow's sparrow
Bachman's warbler
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
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
Some Harmful Nonnative Species in the United States
Fig. 9-14a, p. 199
Fig. 9-14a, p. 199
Deliberately Introduced Species
Purple loosestrife
European starling
African honeybee (“Killer bee”)
Nutria Salt cedar (Tamarisk)
Marine toad (Giant toad)
Water hyacinth Japanese beetle
Hydrilla European wild boar (Feral pig)
Fig. 9-14b, p. 199
Fig. 9-14b, p. 199
Accidentally Introduced Species
Sea lamprey (attached to lake trout)
Argentina fire ant
Brown tree snake
Eurasian ruffe Common pigeon (Rock dove)
Formosan termite Zebra mussel Asian long-horned beetle
Asian tiger mosquito
Gypsy moth larvae
Fig. 9-14, p. 199 Stepped Art
Deliberately introduced species
Purple loosestrife
European starling
African honeybee (“Killer bee”)
Nutria Salt cedar (Tamarisk)
Marine toad (Giant toad)
Water hyacinth
Japanese beetle
Hydrilla European wild boar (Feral pig)
Accidentally introduced species
Sea lamprey (attached to lake trout)
Argentina fire ant
Brown tree snake
Eurasian ruffe
Common pigeon (Rock dove)
Formosan termite
Zebra mussel
Asian long-horned beetle
Asian tiger mosquito
Gypsy moth larvae
Case Study: The Kudzu Vine
Imported from Japan in the 1930s
“ The vine that ate the South”
Could there be benefits of kudzu?
Kudzu Taking Over an Abandoned House in Mississippi, U.S.
Some Accidentally Introduced Species Can Also Disrupt Ecosystems
Argentina fire ant: 1930s • Pesticide spraying in 1950s and 1960s worsened
conditions
Burmese python
Argentina Fire Ant Accidentally Introduced into Mobile, Alabama, U.S.
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
Characteristics of Invader Species and Ecosystems Vulnerable to Invading Species
What Can You Do? Controlling Invasive Species
Other Causes of Species Extinction (1)
Population growth
Overconsumption
Pollution
Climate change
Other Causes of Species Extinction (2)
Pesticides • DDT: Banned in the U.S. in 1972
Bioaccumulation
Biomagnification
Bioaccumulation and Biomagnification
Fig. 9-19, p. 202
DDT in fish-eating birds (ospreys)
25 ppm
DDT in large fish (needle fish) 2 ppm
DDT in small fish (minnows) 0.5 ppm
DDT in zooplankton 0.04 ppm
DDT in water 0.000003 ppm, or 3 ppt
Fig. 9-19, p. 202 Stepped Art
DDT in water 0.000003 ppm, or 3 ppt
DDT in small fish (minnows) 0.5 ppm
DDT in zooplankton 0.04 ppm
DDT in fish-eating birds (ospreys)
25 ppm
DDT in large fish (needle fish) 2 ppm
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
Case Study: Polar Bears and Global Warming
Environmental impact on polar bears • Less summer sea ice • PCBs and DDT
2007: Threatened species list
Polar Bear with Seal Prey
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
White Rhinoceros Killed by a Poacher
Individuals Matter: Jane Goodall
Primatologist and anthropologist
45 years understanding and protecting chimpanzees • Chimps have tool-making skills
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
Bush Meat: Lowland Gorilla
Animation: Humans affect biodiversity
Active Figure: Habitat loss and fragmentation
Video: Bird species and birdsongs
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.
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.
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.)
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
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
Confiscated Products Made from Endangered Species
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
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
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?
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
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
Zoos and Aquariums Can Protect Some Species (2)
Limited space and funds
Critics say these facilities are prisons for the organisms
What Can You Do? Protecting Species
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
The Precautionary Principle
Species: primary components of biodiversity
Preservation of species
Preservation of ecosystems
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