Transcript SUSTAINING WILD SPECIES

SUSTAINING WILD
SPECIES
Species Conservation
Factors affecting Biodiversity
• Increases biodiversity:
• Physically diverse habitat
• Moderate environmental
disturbance
• Small variations in environmental
conditions
• Middle stages of succession
• Evolution
• Decreases biodiversity:
• Environmental stress
• Large environmental
disturbance
• Extreme environmental
conditions
• Severe limitations of resources
• Introduction of exotics
• Habitat loss
• How have human activities affected global
biodiversity?
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Taken over or degraded 40-50% of earth’s surface
Waste or destroy 27% of total net primary productivity
Losing our wetlands and deforestation
Coral reefs
Threatening many organisms with premature extinction
BIODIVERSITY HOT SPOTS
Goals for reducing loss of biodiversity:
• To prevent premature
extinction of species
• To preserve and
restore ecosystems
and aquatic systems
that provide habitats
and resources for
species.
HOW DO BIOLOGISTS
EXTIMATE
EXTINCTION RATES?
HOW DO BIOLOGISTS EXTIMATE EXTINCTION
RATES?
SPECIES -AREA RELATIONSHIP
Scientists observe:
• # species increases with area • assume that an average of 90% loss of habitat causes
the extinction of about 50% of the species living in
that habitat
• but destruction of 10% of the habitat can wipe out all
of the remaining species if they cannot move!
CHARACTERISTICS OF
SPECIES THAT ARE
PRONE TO EXTINCTION:
Characteristic
Examples
Low reproductiv e rate
(K-strategist)
Blue whale, giant panda,
rhinoceros
Specialized niche
Blue whale, giant panda,
Ev erglades kite
Narrow distribution
Manyisland species,
elephant seal, desert pupfish
Feeds at high trophic
lev el
Bengal tiger, bald eagle,
grizzly bear
Fixed migratory patterns
Blue whale, whooping crane,
sea turtles
Rare
Manyisland species,
African v iolet, some orchids
Commerciallyv aluable
Snow leopard, tiger,
elephant, rhinoceros,
rare plants and birds
Large territories
California condor, grizzly
bear, Florida panther
Fig. 22.8, p. 558
Slide 10
What can be done about invasive species?
• Identify characteristics of successful invaders
• Do better inspections
• Identify invader species and pass laws
• Require ships to discharge ballast waters in the ocean not in port
ROLE OF LOSS OF GENETIC DIVERSITY
• LIMITS ABILITY TO SURVIVE
• HOW LOST:
• FOUNDER EFFECT - SUCH A SMALL NUMBER OF INDIVIDUALS
THEY CANNOT SUSTAIN THE POPULATION
• INBREEDING
• DEMOGRAPHIC BOTTLENECK - TOO FEW INDIVIDUALS TO
PERPETUATE POPULATION
• GENETIC DRIFT - UNEQUAL REPRODUCTIVE SUCCESS -SOME
INDIVIDUALS BREED AND DOMINATE THE GENE POOL
Protecting Wild Species
LAWS AND TREATIES
INTERNATIONAL TREATIES
• CITES - CONVENTION ON INTERNATIONAL TRADE IN
ENDANGERED SPECIES - 1975
• 152 countries
• 800 species can not be commercially traded live or as products
• 29,000 species monitored and regulated because they are
threatened
• limited enforcement
• small fines
• much goes on in countries who did not sign
• CONVENTION OF BIOLOGICAL DIVERSITY (CBD)
• 172 countries - not U.S.
• help protect global biodiversity
• very comprehensive treaty
NATIONAL LAWS
• LACEY ACT - 1900 - prohibits transporting live or dead
wildlife products across state borders without a
federal permit
• ENDANGERED SPECIES ACT (ESA) 1975- cannot
import or trade in any product from endangered or
threatened species except for scientific purposes
• must be on the list
• must have a plan for recovery
WHAT ELSE CAN BE DONE?
• ENCOURAGE PRIVATE
LANDOWNERS
• habitat conservation plans
• safe harbor agreements - restore
habitats
• candidate conservation
agreements
• WILDLIFE REFUGES - MOST ARE
WETLANDS
• GENE BANKS, BOTANICAL
GARDENS AND FARMS
• seed banks
• kew gardens
IMPORTANCE OF ZOOS
• USE TWO
TECHNIQUES:
• egg pulling - collect
eggs and hatch in zoos
• captive breeding reintroduce into the
wild
• artificial insemination
• embryo transfer
• incubators
• cross fostering with
similar species
• use databases to match
individuals for mating
WILDLIFE MANAGEMENT
• MANIPULATING WILDLIFE
POPULATIONS (ESPECIALLY
GAME ANIMALS) AND THEIR
HABITATS FOR THEIR
WELFARE AND HUMAN
BENEFITS
• hunting regulations
• harvest quotas
• population management plans
• improving habitats
• using international treaties to
protect migrating game species