Chapter 9
Sustaining Biodiversity
the Species Approach
Background Extinction
• 1/106 (or .0001%) until humans
came along
• Now .1 – 1%
Mass Extinction
• 50 – 95% of species go extinct
• 5 mass extinctions
• Last on 65 million years ago
–Cause?
Levels of Extinction
• Local
• Ecological
• Biological
Animal Species Prematurely
Extinct Due to Human Activities
Endangered vs Threatened
• Endangered Species
–So few survivors may become
extinct soon
• Threatened Species
–Population is dropping rapidly
Endangered Species Act
Characteristics of Vulnerable Species
•
•
•
•
•
•
Low reproductive rate
Specialized niche
Narrow distribution
Feed at high trophic level
Commercially valuable
Large territory
Use Value of Species
• Ecotourism
• Pharmaceuticals (62% of cancer
drugs)
–Rosy Periwinkle + Hodgkin’s
Disease
• Genetic information
–GMOs
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
Foxglove
Digitalis purpurea,
Europe
Digitalis for heart failure
Cinchona
Cinchona ledogeriana,
South America
Quinine for malaria treatment
Neem tree
Azadirachta indica,
India
Treatment of many
diseases, insecticide,
spermicide
Fig. 9-8, p. 190
Intrinsic value
• Species have an right to survive
• We have an ethical duty to try to
preserve species
Biophilia
• Inherent connection with nature
• Biophobia
Grizzly bear
Kirkland’s
warbler
Utah prairie dog Swallowtail
butterfly
Giant
panda
Black-footed
ferret
Mountain
gorilla
Florida
panther
Knowlton
cactus
Florida African elephant
manatee
Humpback Golden lion
tamarin
chub
Siberian
tiger
Whooping Northern Blue whale
spotted owl
crane
California
condor
Hawksbill
sea turtle
Black
rhinoceros
Fig. 9-4, p. 187
HIPPCO
• Habitat alteration
–Island species
–Habitat island
–Habitat fragmentation
–Theory of Island Biogeography
Indian
Tiger
Range 100 years ago
Range today
African
Elephant
Probable range 1600
Range today
Black
Rhino
Range in 1700
Range today
Asian or Indian
Elephant
Former range
Range today
Stepped Art
Fig. 9-11, p. 194
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
• Introduction of nonnative species
• Climate change
• Sale of exotic pets and decorative plants
• Overfishing
• Predator and pest control
Fig. 9-10, p. 193
Birds
• 1/8 of world’s birds are endangered
– Kirtland’s warbler
– Habitat loss, wetlands
– 1 billion fly into windows
– Climate change
• Birds are good environmental indicators
– Live in every climate and biome
– Respond quickly to environmental changes
– Easy to track and count
Nonnative species
• Deliberately introduced species
–98% of food supply (corn, wheat,
rice, cattle, chickens)
–Kudzu
• Meant to control erosion
• Afflicts the South
• Food, paper, pharmaceutical?
Kudzu Taking Over an Abandoned
House in Mississippi, U.S.
Deliberately Introduced Species
Purple
loosestrife
Marine toad
(Giant toad)
European
starling
African honeybee
(“Killer bee”)
Water hyacinth Japanese beetle
Nutria
Hydrilla
Salt cedar
(Tamarisk)
European wild
boar (Feral pig)
Fig. 9-14a, p. 199
Accidentally Introduced Species
• Argentina fire ant
– Mobile Alabama, 1930’s
• Burmese python
– Pets dumped in Everglades
• Zebra mussel
– In ballast water from Europe
– Plagues the great lakes
Accidentally Introduced Species
Sea lamprey
Argentina fire Brown tree snake Eurasian ruffe
(attached to lake
ant
trout)
Formosan termite
Zebra mussel Asian long-horned
beetle
Asian tiger
mosquito
Common pigeon
(Rock dove)
Gypsy moth
larvae
Fig. 9-14b, p. 199
Pollution
• Pesticides
– Kill 1/5 of honeybee colonies
• DDT
– Banned in 1972 (Silent Spring)
– Health risk?
– Bald eagle recovery (417  10,000 breeding pairs)
– Success for ESA
DDT is Fat Soluble
• therefore it can undergo bioaccumulation and
biomagnification
• Bioaccumulation
– Ingested fat soluble chemicals are absorbed into
tissue and accumulate over time
• Biomagnificiation
– Higher level consumers ingest chemicals stored in
all organisms lower on its food chain
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
Stepped Art
Fig. 9-19, p. 202
Bees
• Important pollinators of ornamental and food
crops
• 1/3 of crops are pollinated by insects
worldwide
• In US, 98% of honeybees are commercially
owned
• Bee colony collapse disorder
Polar Bears
•
•
•
•
•
•
Winter vs summer feeding
Global warming
Population declines by 1/3 by 2050
PCBs, DDT accumulates in fat
Russian poachers kill 200 a year
Threatened under ESA
Poaching
• Globally, $10 billion business
• Mountain gorilla = $150,000
– Jane Goodall
•
•
•
•
Panda pelt = $100,000
Tigers 100,000 in 1900; now 3500
Tropical fish
Poachers rarely get caught
International Treaties
• CITES
– Signed by 172 countries
– Has been effective, but member countries can
exempt themselves
• CBD (Convention on Biological Diversity)
– 190 countries (not US, so not very effective)
– Protects ecosystems rather than individual species
ESA
First passed in 1973
• National Marine Fisheries Service identifies
and lists ocean species
• US Fish and Wildlife Species land based
species
• Endangered and threatened
– 92 in 1973 - 1350 in 2007
– Shipments of wildlife must enter one of nine ports
Legal Consequences
• Northern Spotted Owl (jobs vs Nature)
• Eminent Domain?
– Regulatory takings
– Takings legislation
• Habitat Conservation Plans
National Wildlife Refuge System
• Established in 1903
– Pelican Island
– Theodore Roosevelt
• 540 refuges (3/4 are wetland refuges)
• 1/5 of endangered and threatened species
have habitats in NWRS
Seed Banks, Zoos, etc
• Seed (gene) banks
– 100 worldwide, 3 million samples
• Arboreta, Botanical Gardens
– 1600 worldwide (Tyler, Morris arboreta)
• Zoos, aquaria
– Egg pulling
– Captive breeding
• Reintroduction into the wild is rarely successful
California Condor
•
•
•
•
Has been successfully reintroduced
Population declined to 22 in 60’s
135 now in the wild
Lead in hunter ammunition led to poisoning