1. Unit 4: Biodiversity and Endangered Species
Section 2: Threats to Earth’s Diversity

2. Central Case Study: Will we slice through the Serengeti?
Serengeti National Park – Located on the border of Tanzania and Kenya (East Africa)
Comprised of dry, temperate grasslands and savanna biomes
Hosts over 800,000 visitors per year = $3 Billion to local communities (major economic factor)
Tanzania’s government plans to build a highway through park
Issues:
Will cut off yearly migration paths for wildebeest, zebras, etc.
Could encourage poaching by giving easier access to animals
Currently on hold but growing support again for this highway

4. Benefits of Biodiversity
Provide ecosystem services
Help maintain ecosystem function
Enhance food security
Provide drugs and medicines for human use
Boost economies through tourism and recreation
The value of ecosystem services = $48 trillion per year!!!!!!
Biodiversity

5. All Good Things Come to an End
Extinction is a natural process
Populations can die out (extirpation) without the entire species dying
Species go extinct naturally all the time
This is known as the background rate of extinction
However, current extinction rate is 100 to times faster than background rate
Other extinctions are brought on by human activity
#1 Cause of Loss of Biodiversity and Endangerment: Habitat loss and fragmentation (deforestation, pollution, etc.)
Housing developments, farming, damming rivers, domestic grazing
Overharvesting

6. Extinct Species:
Dodo bird, Carolina parakeet, passenger pigeon, Great Auk, Tazmanian Tiger

7. It Ain’t Just a New Thing
Polynesians caused large extinctions of birds when they arrived in places like Hawai’i and New Zealand
Large mammals were decimated in North America and Australia with the arrival of indigenous people

8. Endangered and Threatened Species: Ecological Smoke Alarms
Endangered species: so few individual survivors that it could soon become extinct.
Threatened species: still abundant in its natural range but is likely to become endangered in the near future.

9. Figure 11.3
Endangered natural capital: species that are endangered or threatened with premature extinction largely because of human activities. Almost 30,000 of the world’s species and 1,260 of those in the United States are officially listed as being in danger of becoming extinct. Most biologists believe the actual number of species at risk is much larger.

10. Endangerment can Lead to Extinction
Some species are more at risk than others. Certain characteristics cause this…
Low Reproductive Rate
Specialized Feeding Habits
Feed at high trophic levels
Large size (easy targets/slow movement)
Specialized nesting or breeding areas
Found only in one place or region (endemic)
Fixed migratory patterns
Preys on livestock or people
Behavioral Patterns

11. Biodiversity is decreasing unequally
Percentage of various species types threatened with premature extinction from human activities.

12. IUCN’s Red List
International Union for Conservation of Nature (IUCN) annually puts out the Red List to list species at risk of extinction

13. Living Planet Index

14. Threats to Biodiversity
Conservation biologists summarize the most significant causes of premature extinction as “HIPPO”:
Habitat destruction, degradation, and fragmentation
Invasive species
Population growth (Human)
Pollution
Overharvesting
An actual Hippo… which is also classified as vulnerable… 

15. Invasive Species Examples to know: Zebra Mussel (Great Lakes)
Organisms that have been intentionally or accidentally introduced into an area that they are not native to
Examples to know:
Zebra Mussel (Great Lakes)
Brown tree snake (Guam)
Kudzu (Southeast US)
Cane Toads (Australia)
Asian Carp (Mississippi Valley)

18. Overexploitation Overharvesting for…
Food
Decoration
Medicine
Many of these items are obtained through poaching and are sold illegally on the black market
Bushmeat
Ivory
Pelts/Fur

19. Climate Change’s Effects
Impacts on the Earth’s climate system are global
Extreme weather events (storms) increase stress
Melting sea ice in the Arctic threatens polar bears
Mountaintop species are losing their habitat
A 1.5–2.5C temperature rise could put 20%–30% of plants and animals at increased risk of extinction

20. What are we doing to fix it?
Conservation Biologists are studying ways to save much of Earth’s biodiversity
Environmental Legislation:
****Endangered Species Act (ESA)**** – United States; enacted in 1973; forbids government and citizens from taking any actions that destroy endangered species or their habitats
2013: 1118 U.S. species endangered; 322 threatened
Most Notable Success Story: Bald Eagle; population recovering after ban of DDT in 1973; 2007 – Removed from Endangered Species List

21. What are we doing to fix it?
Environmental Legislation:
Species at Risk Act – Canada; enacted in 2002; scientists have argued that it is too weak and does not protect habitats adequately
****Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)**** - United Nations (169 countries); treaty formulated in 1973; protects endangered species by banning international trade of their body parts
Convention on Biological Diversity – numerous nations; 1992; goals – to conserve biodiversity, use biodiversity sustainably, ensure fair distribution of benefits; helped nations gain economic benefits from ecotourism; Treaty’s overall goal was not met by 2010

22. In-situ Conservation
Leaving the animal where it lives but protecting it.
Ex. Elephants; make laws that prevent poaching and have people to enforce it
Ex. Marine turtles are protected - escape nets must be used on all fishing nets so the turtles can get out and not drown

23. Ex-situ Conservation
Taking the animal out of its habitat & protecting it.
Ex. Zoo’s
2 types:
Captive breeding
Reintroduction programs
Cloning

24. Habitat restoration Focus on hotspots
Restoration - Research and scientific study devoted to restoring, repairing, and reconstructing damaged ecosystems.
Preservation - Setting aside or protecting undisturbed natural areas from harmful human activities.
National parks and reserves
Remediation - Repairing an ecosystem that has been destroyed.
Remove pollution from ecosystem
Mitigation – create new ecosystems to offset known impacts on existing ecosystems