sustaining biodiversity: the species approach
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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 - PowerPoint PPT PresentationTRANSCRIPT
Sustaining Biodiversity: The Species Approach
Chapter 9
Passenger pigeon hunted to extinction by 1900
Commercial hunters used a "stool pigeon”
Archeological record shows five mass extinctions
Human activities: hastening more extinctions?
Core Case Study: The Passenger Pigeon: Gone Forever
Passenger Pigeon
Degrading and destroying biodiversity in many parts of the world and these threats are increasing : 83% of the earth’s land surface
filling in wetlands, converting grasslands and forests to crop fields and urban areas
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 role in premature extinction…….
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
Human Activities Are Destroying and Degrading Biodiversity
continuous low level of extinction extinction rate : expressed as a percentage or
number of species that go extinct/per million species per year 1/1,000,000=.000001 or .0001% ( estimated extinction rate before humans came on the scene)
Background Extinction……….
Premature extinctions due to◦Habitat destruction◦Overhunting
Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up
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
Animal Species Prematurely Extinct Due to Human Activities
Lost Natural capital
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
2000 50 100 150
Endangered species – has so individual survivors that the species could soon become extinct over all or most of it’s natural range
Threatened species - abundant in natural range , but numbers declining
Endangered and Threatened Species Are Ecological Smoke Alarms
Endangered Natural Capital: Species Threatened with Premature Extinction
Fig. 9-5, p. 188Stepped 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
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
Science Focus: Estimating Extinction Rates Is Not Easy
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.
Why Should We Care about Preventing Premature Species Extinction?
Instrumental value◦Use value Ecotourism: wildlife tourism Genetic information
◦Nonuse value Existence value Aesthetic value Bequest value
Ecological value
Species Are a Vital Part of the Earth’s Natural Capital
Natural Capital Degradation: Endangered Orangutans in a Tropical Forest
Endangered Scarlet Macaw is a Source of Beauty and Pleasure
Natural Capital: Nature’s Pharmacy
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?
Science Focus: Using DNA to Reduce Illegal Killing of Elephants for Their Ivory
Intrinsic value: existence value
Edward O. Wilson: biophilia (inherent kinship with the natural world)
Biophobia – against certain organisms
Are We Ethically Obligated to Prevent Premature Extinction?
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
Science Focus: Why Should We Care about Bats?
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.
How do Humans Accelerate Species Extinction?
Habitat destruction, degradation, and fragmentation
Invasive (nonnative) species Population and resource use growth Pollution Climate change Overexploitation
Loss of Habitat Is the Single Greatest Threat to Species: Remember HIPPCO
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
Tropical Biologist Bill Laurance, et al.- edges of forest fragments invaded by vines which take over
How large must a forest fragment be in order to prevent the loss of rare trees? – within 100 meters of the edge of a forest fragment 36% of the biomass of old growth trees is lost within 10-17 years
Science Focus: Studying the Effects of Forest Fragmentation on Old-Growth Trees
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
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
◦ Climate Change
Case Study: A Disturbing Message from the Birds
Distribution of Bird Species in North America and Latin America
Loss of 93% of Brazil’s coastal rain forest
Vultures poisoned from diclofenac in cow carcasses
More wild dogs eating the cow carcasses
More rabies spreading to people
Science Focus: Vultures, Wild Dogs, and Rabies: Unexpected Scientific Connections
Most species introductions are beneficial◦Food◦Shelter◦Medicine◦Aesthetic enjoyment
Nonnative species may have no natural◦Predators◦Competitors◦Parasites◦Pathogens
Some Deliberately Introduced Species Can Disrupt Ecosystems
Some Harmful Nonnative Species in the United States
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)
7100 harmful invasive species introduced into the US
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. 199Stepped 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
Imported from Japan in the 1930s
“ The vine that ate the South” – might spread as far as the Great Lakes by 2040 if climate change (global warming) occurs
Could there be benefits of kudzu? – source of food, for making paper
Case Study: The Kudzu Vine
Kudzu Taking Over an Abandoned House in Mississippi, U.S.
Argentina fire ant: 1930s◦Pesticide spraying in 1950s and 1960s worsened
conditions
Burmese python –imported as a pet from Southeast Asia. Dumped in the Everglades. By 2100 in most of southern US
Some Accidentally Introduced Species Can Also Disrupt Ecosystems
Argentina Fire Ant Accidentally Introduced into Mobile, Alabama, U.S.
Prevent them from becoming established
Learn the characteristics of the species
Set up research programs
Try to find natural ways to control them
Prevention Is the Best Way to Reduce Threats from Invasive Species
Characteristics of Invader Species and Ecosystems Vulnerable to Invading Species
What Can You Do to Control Invasive Species ?
Population growth Overconsumption Pollution Climate change
Other Causes of Species Extinction
Pesticides◦DDT: Banned in the U.S. in 1972
Bioaccumulation
Biomagnification
Other Causes of Species Extinction
Bioaccumulation and Biomagnification
Honeybees responsible for 80% of insect-pollinated plants; 110 commercially grown crops; 1/3 US fruit and vegetable crops
30% drop in population
Dying due to?◦Pesticides◦Parasites◦Bee colony collapse syndrome
Case Study: Where Have All the Honeybees Gone?
Environmental impact on polar bears◦Less summer sea ice◦PCBs and DDT
2007: Threatened species list
Case Study: Polar Bears and Global Warming
Polar Bear with Seal Prey
Poaching and smuggling of animals and plants◦Animal parts◦Pets◦Plants for landscaping and enjoyment
Prevention: research and education
Illegal Killing, Capturing, and Selling of Wild Species Threatens Biodiversity
White Rhinoceros Killed by a Poacher
Indigenous people sustained by bush meat
More hunters leading to local extinction of some wild animals
Rising Demand for Bush Meat Threatens Some African Species
Bush Meat: Lowland Gorilla
Wealthy patrons of some restaurants regard gorilla meat as a source of power and status
We can use existing environmental laws and treaties and work to enact new laws designed to prevent species extinction and protect overall biodiversity.
We can help to prevent species extinction by creating and maintaining wildlife refuges, gene banks, botanical gardens, zoos, and aquariums.
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
How Can We Protect Wild Species from Premature Extinction?
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.)
International Treaties Help to Protect Species
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
Mixed reviews of the ESA◦Weaken it◦Repeal it◦Modify it◦Strengthen it◦Simplify it◦Streamline it
Case Study: The U.S. Endangered Species Act
Confiscated Products Made from Endangered Species
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
Suggested changes to ESA◦Increase the budget◦Develop recovery plans more quickly◦Establish a core of the endangered
organism’s survival habitat
Science Focus: Accomplishments of the Endangered Species Act
1903: Theodore Roosevelt- Pelican Island , Florida – brown pelican
Wildlife refuges -547◦Most are wetland sanctuaries- trumpeter swan◦More needed for endangered plants◦Could abandoned military lands be used for
wildlife habitats?
We Can Establish Wildlife Refuges and Other Protected Areas
Gene or seed banks◦Preserve genetic material of endangered plants by
storing their seeds in refrigerated, low humidity environments
Botanical gardens and arboreta◦Living plants- 1/3 rd of the world’s species
Farms to raise organisms for commercial sale
Gene Banks, Botanical Gardens, and Wildlife Farms Can Help Protect Species
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
What Can You Do? Protecting Species
Largest North American bird
Nearly extinct◦Birds captured and breed in captivity
By 2007, 135 released into the wild◦Threatened by lead poisoning
Case Study: Trying to Save the California Condor
Species: primary components of biodiversity
Preservation of species
Preservation of ecosystems
The Precautionary Principle