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Ch 10
Why? Mainly because of the "HIPPO dilemma."
abitat loss
When people cut down forests, dig mines, build cities, or make roads, they destroy habitats - the places where
plants and animals live.
ntroduced species
Seeds catch on people's clothes. Mice, rats, and birds hitchhike on ships. Snakes stowaway on airplanes. When
these species land in new places, they often crowd out the species already there.
Acid rain destroys forests. Oil spills kill coastal plants and animals. Poisons wash into waterways. Plastic trash
entangles wildlife. It's easy to see how pollution is a big problem for biodiversity.
opulation growth
Nearly 6 billion people live on Earth. Each year, we add 90 million more! All these people use resources for
food, water, medicine, clothes, shelter, and fuel. This leaves fewer resources for Earth's species and habitats.
Some people use more resources than others. For instance, one American uses as much energy as 422 people
in Ethiopia! People everywhere must learn to reduce, reuse, and recycle Earth's resources.
Adapted with permission from the "The HIPPO dilemma" from WOW! A
Biodiversity Primer Educator's Guide published by World Wildlife Fund, ©1994.
• Indicator of healthy ecosystem
• Interconnectedness
– Weakness in one species weakens entire ecosystem
– Weakness in multiple ecosystems weakens biospere
– Where is the tipping point? (JENGA analogy)
• Uses by humans for food, medicine and more
• Intrinsic, aesthetic value
– People appreciate this with ecotourism – and industry
that revolves around people who visit to enjoy nature
and scenery
TED Talk on biodiversity and
Sustainable biodiversity – 20 minutes.
Talk by leader of WWF
• focuses on the way big businesses produces…
moving toward less resources to produce
more efficiently.
3 Types of Biodiversity
• Genetic
– Variations within one species
• i.e. some cardinals redder (more attractive to females), more fluffy
feathers (better adapted to cold), etc.
• Genetic bottleneck: leads to a weaker species, as even when more
members are bred, the variety was already narrowed
• This makes the species less flexible to withstand various changes
in the environment
• Ecosystem
• Ie. Woodlands, prairies, wetlands, deserts, tropical forests, etc.
• Species
– Most common reference
– Multiple endemic species living in one ecosystem
Opposite of biodiversity is…
Monoculture – one single species in an area
Keystone Species
• More important to ecosystems than most
other species
• Their loss would precipitate the collapse of
the ecosystem
• Characteristics that can make a species a
keystone species:
– Structure builders (dams, burrows, etc (not nests,
so much) that other organisms use for habitat
– Apex predators
– Specialty feeders (ex: otters)
– Unique producers (provide food and habitat)
Gopher Tortoise – Keystone Species
• #1 threat (causes 70% of species extinction) is…
• Habitat fragmentation and loss
• Fragmentation:
– Interrupt river flow with dams
– Interrupt migration resting areas (bird migration game)
– Break up hunting areas
• Build roads or fences
• Exotic / invasive species
– Take over niche of endemic species, upsetting balance
– No natural predators
– Organisms in an new area have not evolved defenses
against invasive species
• Examples :
Cane Toads
Kudzu bugs
Burmese pythons
Snake head fish (Chesapeake Bay)
Zebra mussels
• Animal Trafficking
• Poaching
• Hunting
Animal Trafficking
“It’s just to have a pet
no one else
has. That’s what’s
driving this market, “
said Thomas Brady,
Federal Prosecutor on
the case for the
Japanese informant
that complied with
authorities to bring
down the previouslymentioned Japanese
smuggling ring.
According to National Geographic, over 25,000
elephants were killed last year, alone. The ivory from
their tusks is an illegal trade.
• Pollution
Mutated frogs, due to chemicals
in their water
Frogs are indicator species, They
absorb chemicals through their
thin skin
– Pesticides, cleaning agents,
drugs and other chemicals
are making their way into
food webs around the world
– Solid waste
– Fertilizers – in aquatic
ecosystems…leads to
Most vulnerable species
• Limited resources
– Ex: panda eats only bamboo. If bamboo availability
decreases, so does Panda population
• Needs wide range
– Ex: Florida Panther’s hunting range is large
– Development (housing, agriculture and infrastructure)
has fragmented range
• Migrating species
– Rely on multiple habitats
• Exploited by humans
– Over hunting, over fishing, poaching, etc.
Biodiversity hotspots
• 34 identified areas with high endemic (native,
from the area) biodiversity, over 70% reduced
Saving Species
• Captive breeding
– Genetic Bottleneck problem
• Preserving genetic material
– Seeds, sperm, eggs or DNA
• Zoos, aquariums, parks and gardens
– Local examples include Atlanta Zoo, Georgia Aquarium,
Butterfly Gardens in __, and Atlanta Botanical Gardens
The above methods do not solve habitat destruction
problem, so when organisms are released back into
wild, they will face the same pressures.
Saving Species – Preserving Habitats
• Because of interconnectedness, large ranges
must be preserved
• impractical
• Solutions:
1. Focus on biodiversity hotspots
2. ID areas of native habitat that can be preserved
or linked (bear bridges, tunnels for water
passage in everglades, etc.)
3. Promote products that have been harvested
with sustainable practices
– Ex: shade grown coffee
Legal Protection - USA
• Endangered Species Act
• 1973
• Four provisions
1. Compile a list USFWS (US Fish and Wildlife Service)
As of 2005, 1272 species listed
2. Endangered or threatened species may not be:
Caught or Killed
Uprooted from federal land
Sold or traded (including body parts)
3. Feds may not carry out projects that jeopardize
endangered species
4. Species recovery plan for each
Often proposes protecting or restoring species habitat
• Northern Spotted Owl
• Forestry vs. endangered species
• Tellico Dam on Little Tennessee River
• Dam vs. endangered little fish: snail darter
• Dam won
• Snail darter population transported to nearby
• Tipron Kangaroo Rat vs. farmer in Bakersfield,
• Farmer not allowed to plow his field
Legal Protections - International
• IUCN – International Union for the Conservation of Nature
and Natural resources
– Over 200 gov’t agencies and 700 private conservation
– Redlists of endangered
species worldwide
– Sponsors conservation
– Produces CITES (Convention
on International Trade and
Endangered Species)
• Worldwide ban on ivory trade
Legal Protections - International
• Biodiversity Treaty
– Created at Earth Summit, in Rio de Janeiro, Brazil, 1992
– US objected to ratification – didn’t want to take species
biodiversity into account when making economic and
trade decisions
Private Conservation
• WWF – World Wildlife Fund
– Wildlife protection
– Encourages sustainable resource use
• Nature Conservancy
– Buys up land for conservation
– (Hyde Farm on Lower Roswell Road)
• Conservation International –
– biodiversity hotspots and ecosystem conservation
• Greenpeace
– Direct action
– Controversial confrontations
• Balance human needs with conservation
• Ultimate win-win