1. CHAPTER 8: Sustaining Biodiversity: The Species Approach

2. Core Case Study: Polar Bears and Projected Climate Change
20,000 – 25,000 polar bears in Arctic
Hunt seals on winter sea ice
Global warming is quickly reducing the amount of sea ice and how long it lasts in winter
Polar bears have less time to hunt and store fat for summer fasting
Projected 30-35% decline by 2050
Potentially extinct from wild by 2100

3. What Role Do Humans Play in the Premature Extinction of Species?
Concept to Learn in Sect. 8-1: Species are becoming extinct 100 to 1,000 times faster than they were at the start of recorded history, and by the end of this century, the extinction rate is expected be 10,000 times higher than the background rate.

4. Human Activities and Extinction
Background extinction rate: the rate of “normal” extinction of various species as a result of changes in local environmental conditions.
Current annual rate is times that of background extinction (depending on species)
Rate is likely to rise to 10,000 times, bring the annual extinction rate from % to 1%
Question: Is a mass extinction coming?
1. At 1% extinction rate, ¼ of all plant & animal species could be gone by 2050!

5. Most think Current Extinction Rate Estimates Are Conservative!
Species and biodiversity likely decrease in next 50–100 years
1. We are taking over & using up resources!
Biodiversity hotspot rates are much higher than global average extinction rates
1. Ex: tropical rainforests
2. Our efforts need to be focused here!
We are continuing to degrade, simplify, and destroy diverse environments (like rainforests, coral reefs, & estuaries)
1. Could lead to an increase in opportunistic species.

6. Science Focus: Estimating Extinction Rates
Three difficulties
Not easy to document – takes a long time
Only 2 million species of million identified
Little is known about the 2 million species
Therefore, it is difficult/impossible to determine the number of species that are endangered/extinct!

7. Endangered/threatened species: Our Ecological Smoke Alarms
Endangered species: so few survivors, the species could become extinct.
Threatened species: still abundant, but declining in numbers.
The first to go: those species that are large, slow, tasty, or have valuable parts
Some behaviors make species prone to extinction (Ex: passenger pigeon)

8. Case Study: Extinction of the Passenger Pigeon
1813: There were so many, it took 3 days for a flock to pass over
1. one of the most abundant bird species worldwide!
They were extinct by 1900
1. Good to eat
2. Feathers good for pillows
3. Bones good for fertilizer
4. Easy to kill

9. Why Should We Care about Preventing Species Extinction?
Concept to learn in sect. 8-2: 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.

10. The “Value” of A Species
Instrumental value of biodiversity= it’s “usefulness” to us in providing natural capita
Food crops
Genetic information
Medicine (natural medicines)
Bioprospectors (search/find medicines)
Ecotourism (much higher value)
We don’t fully know what we lose when a species goes extinct

11. Ethical Obligations: Do we have one?
Intrinsic (existence) value: many scientists & philosophers believe each species has an inherent right to exist.
Stewardship viewpoint: according to this view, we have an ethical responsibility to protect all species from extinction.
Some believe something less than this:
1. who really cares about mosquitos, fleas, cockroaches, etc.

12. 8-3 How Do Humans Accelerate Species Extinction?
Concept to Learn in Sect. 8-3: The greatest threats to any species are (in order) loss or degradation of its habitat, harmful invasive species, human population growth, pollution, climate change, and overexploitation.

13. Causes of Endangerment and Premature Extinction (HIPPCO)
Habitat destruction
Invasive species
Population growth
Pollution
Climate change
Overexploitation

14. Habitat Destruction
Deforestation of tropical areas is the greatest eliminator of species
1. destruction of coral reefs is 2nd.
Endemic species: The most vulnerable to extinction (found only in 1 place)
Habitat fragmentation: The breaking up of a habitat into pieces, usually caused by human hands
1. Also leads to extinction
2. Hawaii is #1 in species endangered (63%)

15. Case Study: Declining Bird Species
Decline of ~70% of ~10,000 known species
12% threatened (1 in 8) with extinction
Birds around humans have benefited, but forest species have declined
Long-distance migratory birds have seen the greatest decline

16. Case Study: Declining Bird Species
Reasons:
1. Habitat loss (by human hands)
2. Habitat fragmentation (by human hands)
3. Climate change (greatest new threat)
Importance: Birds are environmental indicators!
Perform economic and ecological services
1. control populations of rodents & insects
2. spread plants (pollination & seed excretion)

17. Species Introductions
Most species introduced are beneficial:
1. food crops species (wheat, corn, rice)
2. livestock species (cattle, poultry)
3. pest control
500,000 alien invader species globally
50,000 nonnative species in the U.S.
Some definitely not beneficial, having no natural predators to control them.

18. Case Study: The Kudzu Vine
Kudzu introduced into US to control soil erosion
1. experienced prolific growth
Uses of Kudzu vine:
1. Asians use powdered starch in beverages
2. Edible (all parts!)
Source of tree-free paper
Can control desire for alcohol
Is growing out of control in south US!

19. Disruptions to Ecosystems from Accidentally Introduced Species
Downside of global trade
1. can be found in crates, cargo ships, etc.
Downside of traveling
1. seeds can get caught in tires
Argentina fire ant- huge problem in US
1. have replaced natural species
Burmese python: #’s growing in south US
Zebra mussel: cause damage to pipes, grow easily, reduce food for other mussel species.

20. Prevention of Nonnative Species: Best way to reduce threats!
Identify characteristics of successful invaders & vulnerable ecosystems
Detect and monitor invasions, & make predictions where they will go next
Better inspection of imported goods
Identify harmful invasive species and ban their transfer
Introduce natural predator species
Ships discharge ballast waters at sea

21. Human Choices Drive Extinction!
Human population growth
Excessive, wasteful consumption
1. Both have increased human ecological footprint
2. along the coast will affect aquatic environments (coral reefs)
Use of pesticides (causing the honeybee to become a threatened species)
Climate change (projected to cause extinction of 1/4-1/2 of all plants/animals by 2100.

22. DDT and Bioaccumulation
1950s–1960s fish-eating bird populations drop
DDT is “biologically magnified” in food webs
Bird’s eggshells thin and fragile, therefore, reproduction was reduced.
A 1972 ban has allowed their numbers to grow.

23. Case Study: Where Have All the Honeybees Gone?
Honeybees responsible for 80% of pollination of insect-pollinated plants
Population down 30% since the 1980s, due to:
1. Pesticides
2. Parasitic mites
3. Invasive African honeybees
2008: 36% of honeybee colonies lost due to:
1. Colony collapse disorder
2. Possibly new nicotine-based pesticides to blame.

24. Illegal Killing and Trading of Wildlife Threaten Biodiversity
Poaching endangers many larger animals, rare plants
Over two-thirds die in transit
Illegal poaching trade makes $1.1 million per hour
Wild species depleted by poaching trade
Exotic plants often illegally gathered

25. The Value of Wild Rare Species
The declining populations increase black market values
All rare species are more valuable in the wild (eco-tourism value)
Some ex-poachers turn to eco-tourism
1. recognize the greater $ value

26. Rising Demand for Bush Meat
Demand increasing with population growth
Increased road access has been given to loggers, miners, ranchers greater opportunity to hunt.
Adding to possible extinctions
Popularity of bush meat has caused an increase in the spread of HIV and Ebola virus

27. Sect. 8.4: How Can We Protect Wild Species from Premature Extinction?
What to learn in sect. 8.4: We can reduce species extinction and help to protect overall biodiversity by establishing and enforcing national environmental laws and international treaties, creating a variety of protected wildlife sanctuaries, and taking precautionary measures to prevent such harm.

28. International Treaties & Laws can help!
Convention on International Trade of Endangered Species (CITES)
1. signed by 174 countries
2. bans hunting/capturing/selling of endangered or threatened species.
Convention on Biological Diversity (CBD)
1. signed by 190 countries (not US)
2. focuses on ecosystems & ways to prevent invasive species

29. U.S. Endangered Species Act
Identifies/protects endangered species in US & abroad
National Marine Fisheries Services: identifies endangered ocean species
U.S. Fish and Wildlife Service: identifies other species
Listings based on biological factors (not political or economical)
Forbids federal agency projects that jeopardize listed species or habitats

30. U.S. Endangered Species Act
Fines violators even on private land
Makes it illegal to sell or buy listed species
1,318 species listed
USFWS and NMFS are supposed to prepare a recovery plan for all species listed
1. 86% species have plans as of 2009

31. U.S. Endangered Species Act
Successful recovery plans include American alligator, grey wolf, and bald eagle
Lacks enforcement of imports and exports
Amended to give private landowners economic incentive to save species

32. Science Focus: Accomplishments of the Endangered Species Act
Biologists defend limited success: not quite a failure!
1. Species listed only when gravely threatened
2. Takes long time for species to recover
3. >50% endangered species improving
Need more funding
Develop recovery plans more quickly
Core habitat established when listed

33. Protection of Marine Species
ESA and international treaties also protect endangered marine reptiles and mammals
There are greater challenges to protecting marine species:
1. Limited knowledge of species
Difficulty in monitoring and enforcing treaties
Open oceans

34. Sea Turtles Threatened
Six species critically endangered, due to:
1. Loss or degradation of habitat
2. Illegal harvest of eggs
3. Threats from fishing methods
Protection measures have helped
Read about protective measures set in place for sea turtles

35. Case Study: Protecting Whales
So big, they are easy to kill
International Whaling Commission: established when their numbers were dwindling.
They sets quotas (often ignored)
Have no enforcement powers
In 1986, established a Whaling ban.
1. Although violated, greatly decreased whale kills (Japan, Iceland & Norway were violators)

36. Protecting Species Through Establishing Wildlife Refuges
National Wildlife Refuge System: Established to protect endangered species
Of the refuges created: ~75% are wetland sanctuaries
40 million American visitors (hunting, fishing)
Home to 20% of listed endangered species
Many refuges in disrepair due to underfunding
Many allow mining, oil drilling, and off-road vehicles

37. Protection of Species thru Storing Genetic Information
Gene or seed banks (plants)
1. expensive to maintain
Botanical gardens and arboreta
1. contain living plants, but only 3% of those endangered
Farms – The raising of endangered species for commercial sale removes pressure

38. Zoos and Aquariums for Protection of Species:
Collect species with long-term goal of returning them into habitat
Methods:
1. Egg pulling
2. Captive breeding
Need 100–500 captive individuals to avoid extinction
10,000 is the “magic #” of individuals to maintain capacity for species survival

39. Case Study: Trying to Save the California Condor
Last 22 individuals were captured, and bred in captivity.
They were released a few at a time
2009: 167 condors in the wild
Threatened by lead poisoning (lead pellet shot) from animal carcasses and gut piles
1. left behind by hunters

40. Protection of Species Thru The “Precautionary Principle”
When substantial preliminary evidence indicates an activity could harm humans or the environment, we should take precautionary measures to prevent or reduce the harm
Should be done even if “cause-and-effect” relationships are not yet clearly established
“Better safe than sorry”