Title: Core Case Study: The Passenger Pigeon: Gone Forever
1Core Case Study The Passenger Pigeon Gone
Forever
- Once the most numerous bird on earth.
- In 1858, Passenger Pigeon hunting became a big
business. - By 1900 they became extinct from over-harvest and
habitat loss.
2 What Role Do Humans Play in the Premature
Extinction of Species?
- We are degrading and destroying biodiversity in
many parts of the world, and these threats are
increasing. - Species are becoming extinct 100 to 1,000 times
faster than they were before modern humans
arrived on the earth (the background rate), and
by the end of this century, the extinction rate
is expected to be 10,000 times the background
rate.
3Extinctions Are Natural But Sometimes They
Increase Sharply
- Local Extinction (Extirpation)
- A species is no longer found in an area it once
inhabited but is still found elsewhere in the
world. - Typically the result of habitat destruction or
overhunting and affects more than one species. - Examples wolf and mountain lion in Maine
- Extinction (Global extinction) is Forever.
4Some Human Activities Cause Premature
Extinctions the Pace Is Speeding Up
- Estimates of current annual extinction rate
- 0.01-1.0
- 100 to 1,000 times greater than the background
extinction rate of 0.0001 - Experts predict extinction rates will increase
over the next 50-100 years. -
5Animal Species Prematurely Extinct Due to Human
Activities
- Many animals have become prematurely extinct
because of human activities. - Development, habitat destructions, hunting, etc.
6Animal Species Prematurely Extinct Due to Human
Activities
The first animal species to go are the big, the
slow, the tasty, and those with valuable
parts Edward O. Wilson
(biodiversity expert)
7Endangered Natural Capital Species Threatened
with Premature Extinction
- Threatened (vulnerable) species
- Still abundant in its natural range but is likely
to become endangered in the near future. - Endangered species
- So few individual survivors that it could soon
become extinct.
8Endangered Natural Capital Species Threatened
with Premature Extinction
- Extinct Ex. Dodo, Passenger Pigeon
- Extinct in the wild Ex. Alagoas Curassow
- Captive individuals survive, but there is no
free-living, natural population - Critically endangered Ex. Ivory-billed
Woodpecker, Javan Rhino - Faces an extremely high risk of extinction in
the immediate future - Endangered Ex. Cheetah, Blue Whale, Snow
Leopard - Vulnerable Ex. Lion, Wolverine
- Conservation Dependent Ex. Leopard Shark,
Bristlecone Fir - Would be threatened without active conservation
programs. - Near Threatened Ex. California Red-legged
Frog, Silvery Woolly Monkey - Likely to qualify as threatened soon.
- Least Concern Ex.Brown Rat, Rock Pigeon,
Common Juniper
9Endangered Natural Capital Species Threatened
with Premature Extinction
10Endangered Natural Capital Species Threatened
with Premature Extinction
11Characteristics of Species That Are Prone to
Ecological and Biological Extinction
- Some species have characteristics that make them
more vulnerable to ecological and biological
extinction. - These characteristics make survival harder when
environmental conditions change or when humans
interfere.
12Passenger Pigeon Hunted to extinction
- Former population about 6 billion animals
13Carolina Parakeet extinct
- Habitat loss (forest clearing), over hunted (for
feathers and by farmers who considered them a
pest)
14Ivory-Billed Woodpecker Critically endangered,
possibly extinct
- Once found in southern hardwood swamps and pine
forests
- Comparison of ivory-billed (top) and pileated
woodpecker below)
15Percentage of Various Species Threatened with
Premature Extinction
16Science Focus Estimating Extinction Rates Is
Not Easy
- Three problems with estimating extinction rate
- Hard to document due to length of time
- Only 1.8 million species identified
- Little known about nature and ecological roles of
species identified
17 Why Should We Care about Preventing Premature
Species Extinction?
- We should prevent the premature extinction of
wild species because of the economic and
ecological services they provide and because they
have a right to exist regardless of their
usefulness to us.
18Species Are a Vital Part of the Earths Natural
Capital
- Instrumental value Usefulness in terms of
economic and ecological services - Use value economic goods or services
- Ecotourism wildlife tourism
- Genetic information
- Potential value for medicines, foods
- and other products
- Nonuse value
-
- Existence value happy knowing they are around
- Aesthetic value pleasing to the eye
- Bequest value available for future generations
- Ecological value vital component of the
ecosystem
19 How do Humans Accelerate Species Extinction?
- The greatest threats to any species are
- - loss or degradation of its habitat
- - invasive species
- -human population growth
- - pollution
- - climate change
- -overexploitation.
20Loss of Habitat Is the Single Greatest Threat to
Species Remember H.I.P.P.C.O.
- H.I.P.P.C.O. the most important causes of
premature extinction - Habitat destruction, degradation, and
fragmentation - Invasive (nonnative) species
- Population and resource use growth
- Pollution
- Climate change
- Overexploitation
21Causes of Depletion and Premature Extinction of
World Species
22H.I.P.P.C.O. HABITAT LOSS, DEGRADATION, AND
FRAGMENTATION
- Habitat loss is the GREATEST threat to
biodiversity on this planet. - Deforestation
- Degradation of coral reefs
- Draining wetlands
- Plowing grasslands
- Habitat fragmentation when a large continuous
habitat is divided into smaller, scattered
patches. - By roads, agriculture, urban developed, etc.
23H.I.P.P.C.O. HABITAT LOSS, DEGRADATION, AND
FRAGMENTATION
- Reduction in ranges of four wildlife species,
mostly due to habitat loss and overharvest.
24H.I.P.P.C.O. HABITAT LOSS, DEGRADATION, AND
FRAGMENTATION
- Endemic Species
- Only live in one specific place (geographic
location or habitat type usually islands) - Very vulnerable to extinction as a result of
habitat loss or degradation.
25- The dusky seaside sparrow is extinct. The last of
these birds died in 1987. These sparrows lost
their homes as marshes were destroyed. - Since the Pilgrims landed at Plymouth Rock in
1620, more than 500 species have become extinct
in the U.S. alone.
26H.I.P.P.C.O. INVASIVE SPECIES
- Many nonnative species are beneficial
- Food, Medicine, Aesthetic enjoyment
- However, a few can wipe out native species,
disrupt ecosystems, and cause large economic
losses. - Nonnative species can become a problem since they
may have no natural - Predators
- Competitors
- Pathogens/Diseases
Kudzu vine was introduced to the southeastern
U.S. in the 1930s to control erosion. Since
then, it has taken over native species habitats.
27H.I.P.P.C.O. INVASIVE SPECIES
- Many invasive species have been introduced
intentionally
28H.I.P.P.C.O. INVASIVE SPECIES
- other invasive species have been introduced
unintentionally.
29H.I.P.P.C.O. INVASIVE SPECIES
- The Argentina fire ant was introduced to Mobile,
Alabama in 1932 from South America. - Most likely from ships
- No natural predators
- Pesticide spraying in 1950s and 1960s worsened
conditions - Removed competition
- Lead to pesticide resistance
30Characteristics of Invader Species and Ecosystems
Vulnerable to Invading Species
- Prevention is the best way to reduce threats from
invasive species, because once they arrive it is
almost impossible to slow their spread.
31H.I.P.P.C.O. POPULATION GROWTH
- Humans have increased the species extinction rate
by approximately 1,000 times. - Experts predict that these rates will continue,
or accelerate, in the future.
32H.I.P.P.C.O. POLLUTION
- Human activities can pollute the water, soil, or
air on both on a local and global scale - Water sewage, fertilizers, toxic chemicals and
oil - Soil pesticides, waste, herbicides and toxic
chemicals (which may be washed from the
land into water) - Air smoke and gases such as CO2, CH4 or other
gases that can lead to climate change and
other problems
33H.I.P.P.C.O. POLLUTION
- In the 1950s and 1960s populations of fish
eating birds plummeted to dangerously low levels - Cause? The pesticide known as DDT
- Banned in the U.S. in 1972
- Bioaccumulation
- DDT is fat soluble and can accumulate in tissues
- Biomagnification
- the concentration of DDT in tissues increases as
you go up the trophic levels
34H.I.P.P.C.O. CLIMATE CHANGE
- Climate change caused by global warming could
lead to the extinction of up to 25 of all land
plants and animals by the year 2100. - Many (but not all) extinctions will take place in
the upper latitudes - Polar bears
- 17 Penguin species
35H.I.P.P.C.O. OVEREXPLOITATION
- Some protected species are killed for their
valuable parts or are sold live to collectors. - Killing predators and pests that bother us or
cause economic losses threatens some species with
premature extinction. - Legal and illegal trade in wildlife species used
as pets or for decorative purposes threatens some
species with extinction. - Bush meat indigenous people sustainably hunting
for foodmore people more hunting
36H.I.P.P.C.O. OVEREXPLOITATION
- Poaching
- Rhinoceros are killed for their horns and sold
illegally on the black market. - Elephants are killed for their ivory tusks
- Tigers and other cats killed for their pelts
37 How Can We Protect Wild Species from Premature
Extinction?
- use existing environmental laws and treaties and
work to enact new laws designed to prevent
species extinction and protect overall
biodiversity. - help to prevent species extinction by creating
and maintaining wildlife refuges, gene banks,
botanical gardens, zoos, and aquariums. - According to the precautionary principle, we
should take measures to prevent or reduce harm to
the environment and to human health, even if some
of the cause-and-effect relationships have not
been fully established, scientifically.
38International Treaties Can Help Protect Species
- International treaties have helped reduce the
trade of endangered and threatened species. - One of the most powerful is
- The 1975 Convention on International Trade of
Endangered Species (CITES) - Lists 900 species that cannot be commercially
traded as live specimens or wildlife products - Signed by 172 countries
- Enforcement is difficult
- Probably only 10 of illegal trade in the U.S. is
caught
39Case Study The U.S. Endangered Species Act
- One of the worlds most far-reaching and
controversial environmental laws - The 1973 U.S. Endangered Species Act (ESA)
- Overall goal is to identify and protect
endangered species in the U.S. and abroad. - ESA makes it illegal for Americans to engage in
commerce associated with, or hunt / kill /
collect, endangered or threatened species. - ESA forbids federal agencies (besides defense
department) to carry out / fund projects that
would jeopardize an endangered species.
40Case Study The U.S. Endangered Species Act
- Accomplishments
- More than half of the species listed are stable
or improving - 99 of all listed species are still living
- Challenges
- Very small budget
- Species are listed when faced with serious threat
of extinction - It can take decades to bring a species
populations up - Suggested changes to ESA
- Increase the budget
- Develop recovery plans more quickly
- Establish a core of the endangered organisms
survival habitat
41We Can Establish Wildlife Refuges and Other
Protected Areas
- The U.S. has set aside 544 federal refuges for
wildlife.
42Gene Banks, Botanical Gardens, and Wildlife Farms
Can Help Protect Species
- Gene banks and botanical gardens to raise
threatened species can help prevent extinction. - Zoos and aquariums can help protect endangered
animal species by preserving some individuals
with the long-term goal of reintroduction.
43Gene Banks, Botanical Gardens, and Wildlife Farms
Can Help Protect Species
- Techniques for preserving endangered terrestrial
animal species - Egg pulling
- Captive breeding
- Artificial insemination
- Embryo transfer
- Use of incubators
- Cross-fostering
44The Precautionary Principle
- The Precautionary Principle
- When preliminary evidence indicates that an
activity can harm the environment or human
health, we should take precautionary measures to
prevent or reduce such harm, even if we dont
fully understand the cause/effect relationship. - Better Safe Than Sorry
- Scientists use the precautionary principle to
argue for the - Preservation of species
- Preservation of ecosystems