1. Endangered Species
The last word in ignorance is the person who says of an
animal or plant: “What good is it?” If the land mechanism
as a whole is good, then every part of it is good, whether we
understand it or not. Harmony with the land is like harmony
with a friend; you cannot cherish his right hand and chop
off his left---from The Sand County Almanac by Aldo
Leopold
Tuesday, July 26, 2011
2. Endangered or Threatened...
Endangered Species- so few
survivors of the species that it could
become extinct over all or most of
its natural range.
Threatened species- still abundant,
but because of declining numbers a
species is likely to become
endangered
Experts feel that it is likely that one-
third of the 21,000 plant and animal
species in the US are threatened.
Tuesday, July 26, 2011
3. Extinction Facts:
Extinction History
•
Extinction has taken place the entire time
species have been on the planet
•
Most extinction occurs over thousands, if not
millions of years
•
Extinction spasms have occurred (mass #’s
of species lost in short period—dinosaurs)
Measuring Extinction and Extinction Rate
•
Check fossil history for species that no
longer exist Ivory-billed woodpecker
•
Compare fossils to present species
•
Compare historical data (Colonial data on
islands documenting bird species, for
instance)
•
Establish species inventories and monitor
increasing and declining abundance
(Audubon)
Yangtze River Dolphin
Tuesday, July 26, 2011
4. Extinction continued...
E.O. Wilson (Harvard) fears that the present extinction rate
(0.1-1.0% per year) is 1,000-10,000 times greater than before
humans (prehistoric humans were a big factor) were on Earth. An
extinction rate of 1% would cut the number of species on Earth by
50% by 2100.
Projecting extinction rates
•
Species-area relationship
•
A 90% loss in habitat equals a 50% extinction of species
•
Greatest danger in the world’s biological hotspots- concentrations
of highest biodiversity
•
Rain forests, grasslands and savannahs, coral reefs
E.O. Wilson
Mass extinctions took place long before humans, but there are two
major differences
•
They are taking place over decades rather than thousands or
millions of years
•
We are eliminating many biologically diverse environments
(rainforests, reefs, wetlands, estuaries) that in the past served as
the evolutionary center for the 5-10 million year recovery.
Tuesday, July 26, 2011
5. Instrumental vs. intrinsic value: Are
some species more ‘valuable’ than
others?
•
Instrumental value: major economic and/
or ecological importance to us
•
Bees/apple trees; bats/banana trees:
ecological/economic value
•
Humpback whales: ecotourism
(economic)
•
Intrinsic value: species has its own right to
live and play its own ecological role
•
We tend to focus more on species of
instrumental value
Tuesday, July 26, 2011
6. H.I.P.P.O. = Greatest extinction threats
•
Habitat destruction and
fragmentation i.e. deforestation
causes decline in biodiversity
•
Invasive species: non-natives lack
predators/diseases and displace
natives
•
Population growth: human
population spreads to wild areas,
farm expansion i.e. Rwanda
•
Pollution: air pollution-forests
•
Over harvest: marine fisheries,
whaling, poaching of terrestrial
species
Tuesday, July 26, 2011
7. Climate change as
an extinction threat...
•
Long-term changes in
precipitation and
temperature
•
Dramatically altering
habitats in 70% of Polynya
alpine and polar regions
•
Tropical alpine areas
(Mt Kilimanjaro)
•
Arctic (polar bears;
Bowhead whales)
Bowhead
Whale
Tuesday, July 26, 2011
8. Some important legislation protecting
wild species
Endangered Species Act (ESA) and Marine Mammal Protection Act (MMPA)
•
USFWS and NMFS identifies lists of threatened and endangered species
•
Forbid federal agencies from carrying out, authorizing, or funding projects that
jeopardize a threatened or endangered species or its habitat
•
Habitat Conservation Plans (HCP’s) weaken this law somewhat
•
HCP’s developed in response to situations on private land where endangered species
might be found (bald eagles nesting on SAS land)
National Environmental Policy Act (NEPA) of 1970
•
Requires that an environmental impact statement (EIS) be conducted for every major
project likely to affect environmental quality
•
EIS must list pros and cons, species affected, and alternatives to the project
•
Also a cost-benefit analysis is done
Convention on International Trade in Endangered Species (CITES) of 1975
•
International treaty signed by 160 countries
•
Prohibits trade in live animals or animal products that are endangered
•
Restricts trade in other species that are threatened
Tuesday, July 26, 2011
9. Your Endangered Species Keynote
project...
• Choose an endangered • How can these threats
species (in your home be minimized?
state, perhaps)
• What is being done?
• What is the population
status? • Is there legislation or an
environmental group
• What is the role of the helping the species?
species?
• What is the chance for
• What are the threats? survival?
Tuesday, July 26, 2011
