Transcript Ch 9

Sustaining Biodiversity:
The Species Approach
Chapter 9
Which statement describes you?
a. As long as it stays in its space, wildlife is okay.
b. As long as I do not need its space, wildlife is okay.
c. I have the right to use wildlife habitat to meet my
own needs.
d. When you have seen one redwood tree,
elephant, or some other form of wildlife, you have
seen them all. So lock up a few of each species
in a zoo or wildlife park an don’t worry about
protecting the rest.
e. Wildlife should be protected.
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
 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 – continuous low level
extinction rate. Pre-human rate = .0001%
• Current rate is 1,000x background rate
 Mass extinction: extinction of many species in
a relatively short period of time.
- 5 have occurred
- Are we in the middle of a 6th?
 Causes?
Some Human Activities Cause Premature
Extinctions; the Pace Is Speeding Up (1)
 Levels of species extinction
• Local extinction
• Ecological extinction
• Biological extinction
Some Human Activities Cause Premature
Extinctions; the Pace Is Speeding Up (2)
• Growth of human population will increase this
• Rates are higher where there are more
endangered species ex: Hawaii – “endangered
species capital of the world”
• Tropical forests and coral reefs, wetlands and
estuaries being destroyed
Endangered and Threatened Species Are
Ecological Smoke Alarms
 Endangered species – so few surviving that
they are in danger of becoming extinct
 Threatened species, vulnerable species that
have low populations and could become
 Species of Special Concern numbers are
decreasing and habitat is being reduced.
Characteristics Low reproductive
rate (K-strategist)
of Species
That Are Prone Specialized
to Ecological
and Biological Narrow
Feeds at high
trophic level
Large territories
Blue whale, giant
panda, rhinoceros
Blue whale, giant
panda, Everglades
Elephant seal,
desert pupfish
Bengal tiger, bald
eagle, grizzly bear
Blue whale,
whooping crane,
sea turtle
African violet,
some orchids
Snow leopard, tiger,
elephant, rhinoceros,
rare plants and birds
California condor,
grizzly bear, Florida
Fig. 9-5, p. 188
Endangered Natural Capital: Species
Threatened with Premature Extinction
Utah prairie Swallowtail Humpback Golden lion Siberian
Black-footed Whooping Northern Blue whale
crane spotted owl
California Hawksbill
sea turtle rhinoceros
Fig. 9-4, p. 187
Percentage of Various Species
Threatened with Premature Extinction
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.
Importance of Biodiversity
 Intrinsic
value/Existence value
- inherent
right to exist and play its
ecological roles regardless of it’s use to
 Instrumental value - use values that
benefit people
 Aesthetic
 Bequest
value - appreciation and beauty
value - leaving natural capital
for use by future generations
Nature’s Pharmacy
Pacific yew
Taxus brevifolia,
Pacific Northwest
Ovarian cancer
Rauvolfia sepentina,
Southeast Asia
Anxiety, high blood
Digitalis purpurea,
Digitalis for heart
Cinchona ledogeriana,
South America
Quinine for malaria
Rosy periwinkle
Cathranthus roseus,
Hodgkin's disease,
lymphocytic leukemia
Neem tree
Azadirachta indica,
Treatment of many
diseases, insecticide,
Fig. 9-8, p. 190
Science Focus: Using DNA to Reduce
Illegal Killing of Elephants for Their Ivory
 1989 international treaty against poaching
 Poaching on the rise
 Track area of poaching through DNA analysis of
 Elephants damaging areas of South Africa:
Should they be culled?
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
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
 Invasive (nonnative) species
 Population and resource use growth
 Pollution
 Climate change
 Overexploitation
 Island species are especially vulnerable:
- many are endemic – found nowhere else in the
 Habitat islands are isolated mainland areas
Habitat fragmentation – occures when large
contiguous areas are divided into smaller,
scattered and isolated patches by
- developed or disturbed land.
- Roads
- Logging
- Agriculture
- etc
Climate change will have the biggest impact on
biodiveristy over the next 50 years.
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
• Introduction of nonnative
• Climate change
• Sale of exotic pets and decorative
• Overfishing
• Predator and pest control
Fig. 9-10, p. 193
Range 100 years ago
Range today
Probable range 1600
Range today
Range in 1700
Range today
Asian or Indian
Former range
Range today
Reduction in the Ranges of 4 Wildlife Species
Fig. 9-11, p. 194
Case Study: A Disturbing Message
from the Birds (1)
Birds are Indicator Species
 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
Ingestion of toxic lead shotgun pellets
Case Study: A Disturbing Message
from the Birds (3)
 Greatest new threat: Climate
 Environmental indicators
 Economic and ecological services
Distribution of Bird Species in North
America and Latin America
The Ten Most Threatened Song Birds
in the United States
Science Focus: Vultures, Wild Dogs, and
Rabies: Unexpected Scientific Connections
 Vultures poisoned from diclofenac in cow
 More wild dogs eating the cow carcasses
 More rabies spreading to people
Some Deliberately Introduced Species
Can Disrupt Ecosystems
 Most species introductions are beneficial
Aesthetic enjoyment
 When Non-native species have no natural
• Predators
• Competitors
• Parasites
• Pathogens
BIG PROBLEM!!!! They become INVASIVE!!!!
Deliberately Introduced Species
Marine toad
(Giant toad)
African honeybee
(“Killer bee”)
Water hyacinth
Salt cedar
European wild
boar (Feral pig)
Fig. 9-14a, p. 199
Accidentally Introduced Species
Sea lamprey
(attached to
lake trout)
Argentina fire
Formosan termite Zebra mussel
Brown tree
Asian longhorned beetle
Eurasian ruffe Common pigeon
(Rock dove)
Asian tiger
Gypsy moth
Fig. 9-14b, p. 199
Case Study: The Kudzu Vine … “ The
vine that ate the South”
 Imported from Japan in the 1930s for erosion
 Grows 2 inches every hour!
 Can’t be controlled by normal weed control
 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
 Burmese python in Everglades
Argentina Fire Ant Accidentally
Introduced into Mobile, Alabama, U.S.
Prevention Is the Best Way to Reduce
Threats from Invasive Species
 Ban transfer of species across borders with
international treaties
 Inspect goods before they enter the country
 Require discharge of ballast water out at sea
before entering port
 Filter ballast water from ships
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 – stored in fat tissue in body
 Biomagnification – animals higher in the food
chain have higher amounts of toxin.
Bioaccumulation and Biomagnification
Case Study: Where Have All the
Honeybees Gone?
 Honeybees responsible for 80% of insectpollinated 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
– poles are warming 2x faster than the rest of the
- Bears can’t get enough seals in summer to fatten
up for winter
• PCBs and DDT – bimagnified in arctic food
chains. Bears are top level consumers.
 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
• 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
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-andeffect 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
• Restricts international trade in endangered species
 Convention on Biological Diversity (BCD)
• Focuses on ecosystems & sustainable use of
- Prevents spread of invasive species
- Commited to protecting genetic resources in
biodiversity and making sure all people have access
to it’s benefits
• Ratified by 190 countries (not the U.S.)
Case Study: The U.S. Endangered Species
Act 1973, amended in 1982, 1983, and 1985
Read the Case Study on p 206 on the ESA. One person in each
group will look for the following:
1)Specific description of responsibilities and tools that help protect
2)What are some loopholes or ways the ESA are circumvented
that weaken it’s effectiveness? Discuss ways to prevent these
3)Choose 4 of the efforts to weaken the ESA and discuss with
your group why you think they would be good or bad
4)Read the Science Focus on p 209. What are the major
accomplishments of the ESA? Describe the 3 major changes
Confiscated Products Made from
Endangered Species
Science Focus: Accomplishments
of the Endangered Species Act (1)
 Species listed only when serious danger of
 Takes decades for most species to become
endangered or extinct
 More than half of the species listed are stable or
 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 – benefit migratory
water fowl like ducks and wading birds
• 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
Zoos and Aquariums Can Protect
Some Species (2)
 Limited space and funds
 Critics say these facilities are prisons for the
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
 Prevent introduction of nonnative species