Sustaining Biodiversity:
The Species Approach
Key Concepts
 Human effects on extinction rates
 Biodiversity and extinction
 How human activities endanger wildlife
 Preventing extinction
 Reconciliation ecology
Types of Species Extinction
Local extinction
Ecological extinction
Biological extinction
Extinct Species
Passenger
pigeon
Great auk
Dodo
Dusky seaside
sparrow
Aepyornis
(Madagascar)
Endangered and Threatened Species
 Endangered species
 Threatened (vulnerable) species
 The red list
Florida
manatee
Northern spotted
owl (threatened)
Gray wolf
Florida panther
© 2004 Brooks/Cole-Thomson Learning
Bannerman's
turaco (Africa)
Grizzly bear
(threatened)
Kirtland's
warbler
White top
pitcher plant
Arabian oryx
(Middle East)
African elephant
(Africa)
Mojave desert
tortoise
(threatened)
Swallowtail
butterfly
Humpback
chub
Golden lion
tamarin
(Brazil)
Siberian tiger
(Siberia)
West Virginia
Giant panda
spring salamander (China)
Mountain gorilla
(Africa)
Pine barrens
tree frog
(male)
Whooping
crane
Knowlton
cactus
Swamp
pink
Hawksbill sea
turtle
Blue whale
El Segundo blue
butterfly
Florida
manatee
Northern spotted
owl (threatened)
Gray wolf
Florida panther
Devil's hole
pupfish
Snow leopard
(Central Asia)
Symphonia
(Madagascar)
Black-footed
ferret
Ghost bat
(Australia)
California
condor
Black lace
cactus
Black rhinoceros
(Africa)
Bannerman's
turaco (Africa)
Utah prairie dog
(threatened)
Oahu tree
snail
34% (51% of freshwater species)
Fish
24%
Mammals
20%
Reptiles
Plants
Birds
14%
12%
Extinction Rates
 Background (natural) rate of extinction
 Mass
extinction
 Extinction
spasm
Characteri
stics of
Extinction
Prone
Species
Characteristic
Examples
Low reproductive rate
(K-strategist)
Blue whale, giant panda,
rhinoceros
Specialized niche
Blue whale, giant panda,
Everglades kite
Narrow distribution
Many island species,
elephant seal, desert pupfish
Feeds at high trophic
level
Bengal tiger, bald eagle,
grizzly bear
Fixed migratory patterns
Blue whale, whooping crane,
sea turtles
Rare
Many island species,
African violet, some orchids
Commercially valuable
Snow leopard, tiger,
elephant, rhinoceros,
rare plants and birds
Large territories
California condor, grizzly
bear, Florida panther
Problems with estimating
extinction rates
Extinction not easily documented over
time
Many species remain unidentified
Little is known about most identified
species
Estimating Extinction Rates
Species-area relationships
Population viability analysis (PVA)
Minimum viable population (MVP)
Minimum dynamic area (MDA)
Causes of Depletion of Wild Species
 Human population growth
 Increasing per capita resource use
 Endangered centers of biodiversity
 Environmental destruction
 Spread of opportunistic species
Causes of Premature Extinction of
Wild Species
Habitat
loss
Overfishing
Pollution
Habitat degradation
and fragmentation
Climate change
Commercial
hunting and poaching
Introducing
nonnative species
Predator and pest control
Secondary Causes
•Population growth
•Rising resource use
•No environmental
accounting
•Poverty
Basic Causes
Sale of exotic pets
and decorative plants
Why are wild species Important?
Rebuilding biodiversity is slow
Instrumental value
Genetic information
Eco-tourism
Ecological value
Intrinsic value
Range in 1700
Range today
(about 2,400 left)
Black Rhino
Probable range 1600
Range today
(300,000 left)
African Elephant
Former range
Range today
(34,000–54,000 left)
Asian or Indian Elephant
Range 100 years ago
Range today
(about 2,300 left)
Indian Tiger
Habitat Loss and Degradation
Greatest threat to species
“HIPPO”
Habitat destruction
Invasive species
Population (humans) growth
Pollution
Overharvesting
Threats from Exotic Species
Arrival
Roles of nonnative species
Prevention
Sea lamprey
(attached to lake trout)
Argentina fire ant
Brown tree snake
Eurasian muffle
Common pigeon
(Rock dove)
Formosan termite
Zebra mussel
Asian long-horned
beetle
Asian tiger mosquito
Gypsy moth larvae
Accidentally introduced Species
Purple loosestrife
Marine toad
European starling
African honeybee
(“Killer bee”)
Water hyacinth
Japanese beetle
Nutria
Salt cedar
(Tamarisk)
Hydrilla
Deliberately introduced Species
European wild boar
(Feral pig)
Cerulean warbler
Florida scrub jay
Sprague’s pipit
Bichnell’s thrush
California gnatcatcher Kirtland’s warbler
Blacked-capped vireo
Golden-cheeked
warbler
Henslow’s sparrow
Bachman’s warbler
Kudzu
1918
2000
Other Extinction Threats
Hunting and Poaching
Predators and Pest Control
Exotic Pets and Decorative Plants
Climate Change and Pollution
Protecting Wild Species: The
Research and Legal Approaches
 International Treaties: CITES and CBD
 U.S. National Laws: Lacey Act
Endangered Species Act
 Habitat recovery plans
Endangered Species Act (ESA)
Private versus public poverty rights
Win-win compromises
Weaken or strengthen the Act?
Protecting Wild Species: The
Sanctuary Approach
 Wildlife refuges and protected areas
 Gene banks, botanical gardens, and farms
 Zoos and Aquariums
Reconciliation Ecology
 Establishing and maintaining new habitats
 Being good neighbors to wildlife
 Reward voluntary conservation efforts
2
4
3
5
Top Six Hot Spots
6
1 Hawaii
2 San Francisco Bay area
3 Southern Appalachians
4 Death Valley
5 Southern California
6 Florida Panhandle
Concentration of rare species
1
Low
Moderate
High
North American-South
American flyways
European-African
flyways
Asian flyways
What can an individual do?
Do not buy furs, ivory products, and other
materials made from endangered or threatened
animal species.
Do not buy wood and paper products produced by
cutting remaining old-growth forests in the tropics.
Do not buy birds, snakes, turtles, tropical fish, and
other animals that are taken from the wild.
Do not buy orchids, cacti, and other plants that
are taken from the wild.