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