1. Sustaining Biodiversity: The Species Approach
Chapter 9

2. Core Case Study: The Passenger Pigeon: Gone Forever
Passenger pigeon hunted
to extinction by 1900
John J audobon witness
one flock that took 3 days
to fly over
Archeological record
shows 5mass extinctions
from natural events
Human activities: hastening 6th mass extinction?

3. 9-1 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.

4. Human Activities Are Destroying and Degrading Biodiversity
Human activity has disturbed at least half of the earth’s land surface
Fills in wetlands
Converts grasslands and forests to crop fields and urban areas
Degraded aquatic biodiversity
Premature extinctions due to
Habitat destruction
Overhunting

5. Extinctions Are Natural but Sometimes They Increase Sharply
Background extinction- low levels of extinction (typically before civilizations)
Extinction rate- % or # compared to time
Mass extinction: causes?
Levels of species extinction
Local extinction
Ecological extinction
Biological extinction

6. Animal Species Prematurely Extinct Due to Human Activities
Passenger pigeon
Great auk
Dodo
Golden toad
Aepyornis (Madagascar)
Why are there more birds listed?

7. Effects of a 0.1% Extinction Rate
# of species existing
Effects of a 0.1% extinction rate
5 million
14 million
50 million
100 million
Number of years until one million species are extinct
200 50
100
150
14,000 extinct per year
50,000 extinct per year
100,000 extinct per year

8. Endangered and Threatened Species Are Ecological Smoke Alarms
Endangered species; risk of extinction
Threatened species; vulnerable species
TOP CAUSES – IN ORDER
Degradation or loss of Habitats
Invasive species
Human Population growth
Pollution
Climate changes
Overexploitation
HIPPCO

9. Endangered Natural Capital: Species Threatened with Premature Extinction
Grizzly bear
Kirkland’s
warbler
Knowlton
cactus
Florida
manatee
African elephant
Utah prairie dog
Swallowtail
butterfly
Humpback
chub
Golden lion
tamarin
Siberian tiger
Giant panda
Black-footed
ferret
Whooping crane
Northern
spotted owl
Blue whale
Mountain gorilla
Florida panther
California
condor
Hawksbill
sea turtle
Black rhinoceros X

10. Characteristic Examples Low reproductive rate (K-strategist)
Blue whale, giant panda, rhinoceros
Characteristic
Examples
Specialized niche
Blue whale, giant panda, Everglades kite
Narrow distribution
Elephant seal, desert pupfish
Feeds at high trophic level
Bengal tiger, bald eagle, grizzly bear
Fixed migratory patterns
Blue whale, whooping crane, sea turtle
Rare
African violet, some orchids
Figure 9.5
Characteristics of species that are prone to ecological and biological extinction. Question: Which of these characteristics helped lead to the premature extinction of the passenger pigeon within a single human lifetime?
Commercially valuable
Snow leopard, tiger, elephant, rhinoceros, rare plants and birds
Large territories
California condor, grizzly bear, Florida panther
Stepped Art
Fig. 9-5, p. 188

11. Percentage of Various Species Threatened with Premature Extinction

12. Science Focus: Estimating Extinction Rates Is Not Easy
Three problems
Hard to document due to length of time
Only 1.8 million species identified out of +/- 100 M
Little known about nature and ecological roles of species identified
Apply models that are not very accurate
Calculations are probably much lower than the actual extinction rates

13. 9-2 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.
Use value
Ecotourism: wildlife tourism
Genetic information – DNA is now helping in tracking illegal activity
Nonuse value
Existence value – just knowing
Aesthetic value – feels good
Bequest value – save for the future
Ecological value species diversity is key to energy flow, nutrient recycling, and population control

14. Natural Capital Degradation: Endangered Orangutans in a Tropical Forest

15. Natural Capital: Nature’s Pharmacy

16. Endangered Scarlet Macaw is a Source of Beauty and Pleasure

17. Science Focus: Using DNA to Reduce Illegal Killing of Elephants for Their Ivory
1989 international treaty against poaching elephants
Poaching on the rise
Track area of poaching through DNA analysis of elephants
Elephants damaging areas of South Africa: Should they be culled?

18. Science Focus: Why Should We Care about Bats?
Vulnerable to extinction
Slow to reproduce
Human destruction of habitats
Important ecological roles
Feed on crop-
damaging nocturnal insects
Pollen-eaters
Fruit-eaters
Unwarranted fears of bats

19. NATURAL CAPITAL DEGRADATION
Causes of Depletion and Premature Extinction of Wild Species
Underlying Causes
• Population growth
• Rising resource use
• Undervaluing natural capital
• Poverty
Figure 9.10
Underlying and direct causes of depletion and premature extinction of wild species (Concept 9-3). The major direct causes of wildlife depletion and premature extinction are habitat loss, degradation, and fragmentation. This is followed by the deliberate or accidental introduction of harmful invasive (nonnative) species into ecosystems. Question: What are two direct causes that are related to each of the underlying causes?
Direct Causes
• Habitat loss
• Pollution
• Commercial hunting and poaching
• Habitat degradation and fragmentation
• Climate change
• Sale of exotic pets and decorative plants
• Overfishing
• Introduction of nonnative species
• Predator and pest control
Fig. 9-10, p. 193

20. Reduction in ranges -habitat loss -hunting Indian Tiger
Range 100 years ago
Range today
Black Rhino
Range in 1700
Range today
Reduction in ranges
-habitat loss
-hunting
African Elephant
Probable range 1600
Range today
Asian or Indian Elephant
Former range
Range today
Figure 9.11
Natural capital degradation: reductions in the ranges of four wildlife species, mostly as the result of habitat loss and hunting. What will happen to these and millions of other species when the world’s human population doubles and per capita resource consumption rises sharply in the next few decades? See an animation based on this figure at CengageNOW. Question: Would you support expanding these ranges even though this would reduce the land available for people to grow food and live on? Explain. (Data from International Union for the Conservation of Nature and World Wildlife Fund)
Stepped Art
Fig. 9-11, p. 194

21. Science Focus: Studying the Effects of Forest Fragmentation on Old-Growth Trees
Tropical Biologist Bill Laurance, et al.
How large must a forest fragment be in order to prevent the loss of rare trees?

22. Case Study: A Disturbing Message from the Birds
Habitat loss and fragmentation of the birds’ breeding habitats
Forests cleared for farms, lumber plantations, roads, and development
Intentional or accidental introduction of nonnative species
Eat the birds
Seabirds caught and drown in fishing equipment
Migrating birds fly into power lines, communication towers, skyscrapers, and now windmills
Other threats
Oil spills
Pesticides
Herbicides
Ingestion of toxic lead shotgun pellets

23. Case Study: A Disturbing Message from the Birds
Greatest new threat: Climate change
Environmental indicators
Live in every biome/climate
Easy to track and count
Respond quickly to changes
Economic and ecological services
Pollination, scavenger clean up, rodent & insect pop controls, disperse seeds

24. Distribution of Bird Species in North America and Latin America

25. The Ten Most Threatened Song Birds in the United States

26. Science Focus: Vultures, Wild Dogs, and Rabies: Unexpected Scientific Connections
Vultures poisoned from diclofenac in cow carcasses
More wild dogs eating the cow carcasses
More rabies spreading to people

27. Some Deliberately Introduced Species Can Disrupt Ecosystems
Most species introductions are beneficial
Food
Shelter
Medicine
Aesthetic enjoyment
Nonnative species may have no natural
Predators
Competitors
Parasites
Pathogens

28. Some Harmful Nonnative Species In America
Deliberately Introduced Species
Purple loosestrife
European starling
African honeybee (“Killer bee”)
Nutria
Salt cedar (Tamarisk)
Figure 9.14
Some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.
Marine toad (Giant toad)
Water hyacinth
Japanese beetle
Hydrilla
European wild boar (Feral pig)
Fig. 9-14a, p. 199

29. Accidentally Introduced Species
Sea lamprey (attached to lake trout)
Argentina fire ant
Brown tree snake
Eurasian ruffe
Common pigeon (Rock dove)
Figure 9.14
Some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.
Formosan termite
Zebra mussel
Asian long-horned beetle
Asian tiger mosquito
Gypsy moth larvae
Fig. 9-14b, p. 199

30. Case Study: The Kudzu Vine
Imported from Japan in the 1930s
To control erosion rates
“ The vine that ate the South”
Could there be benefits of kudzu?

31. Some Accidentally Introduced Species Can Also Disrupt Ecosystems
Argentina fire ant: 1930s
Stowaway on a boat shipment
Pesticide spraying in 50-60s
worsened conditions
Trying to develop biological controls like fungus that kills and does not harm environment
Burmese python – dumped pet
Snake hunts

32. Characteristics of Invader Species and Ecosystems Vulnerable to Invading Species

33. Prevention Is the Best Way to Reduce Threats from Invasive Species
Prevent them from becoming established
Learn the characteristics of the species
Set up research programs
Try to find natural ways to control them

34. Other Causes of Species Extinction
Pesticides
DDT: Banned in the U.S. in 1972
Fat soluble pesticide stored in animal bodies
Rachel Carson – pioneering environmentalist
Biomagnification

35. DDT in fish-eating birds (ospreys)
25 ppm
DDT in large fish (needle fish)
2 ppm
DDT in small fish (minnows)
0.5 ppm
DDT in zooplankton 0.04 ppm
Figure 9.19
Bioaccumulation and biomagnification. DDT is a fat-soluble chemical that can accumulate in the fatty tissues of animals. In a food chain or web, the accumulated DDT can be biologically magnified in the bodies of animals at each higher trophic level. The concentration of DDT in the fatty tissues of organisms was biomagnified about 10 million times in this food chain in an estuary near Long Island Sound in the U.S. state of New York. If each phytoplankton organism takes up from the water and retains one unit of DDT, a small fish eating thousands of zooplankton (which feed on the phytoplankton) will store thousands of units of DDT in its fatty tissue. Each large fish that eats 10 of the smaller fish will ingest and store tens of thousands of units, and each bird (or human) that eats several large fish will ingest hundreds of thousands of units. Dots represent DDT. Question: How does this story demonstrate the value of pollution prevention?
DDT in water ppm, or 3 ppt
Stepped Art
Fig. 9-19, p. 202

36. Case Study: Where Have All the Honeybees Gone?
Honeybees responsible for 80% of insect-pollinated plants
Dying due to?
Pesticides
Parasites
Bee colony collapse syndrome

37. Case Study: Polar Bears and Global Warming
Environmental impact on polar bears
Less summer sea ice
PCBs (used a coolants/lubricants) and DDT
2007: Threatened species list

38. Poaching and smuggling of animals and plants
Illegal Killing, Capturing, and Selling of Wild Species Threatens Biodiversity
Poaching and smuggling of animals and plants
Animal parts
Pets
Plants for landscaping and enjoyment
Prevention: research and education

39. White Rhinoceros Killed by a Poacher

40. Individuals Matter: Jane Goodall

41. Rising Demand for Bush Meat Threatens Some African Species
Indigenous people sustained by bush meat
More hunters leading to local extinction of some wild animals

42. 9-4 How Can We Protect Wild Species from Premature Extinction?
According to the precautionary principle, we should take measures to prevent or reduce harm to the environment and to human health
Species: primary components of biodiversity
Preservation of species
Preservation of ecosystems

43. International Treaties Help to Protect Species
1975: Convention on International Trade in Endangered Species (CITES)
Signed by 172 countries
Convention on Biological Diversity (BCD)
Focuses on ecosystems
Ratified by 190 countries (not the U.S.)
Endangered Species Act (ESA): 1973 and later amended in 1982, 1983, and 1985
Identify and protect endangered species in the U.S. and abroad
Hot Spots (area with concentration of endangered animals)
Habitat Conservation Plan (HCP) colony

44. Science Focus: Accomplishments of the Endangered Species Act
Species listed only when serious danger of extinction
Takes decades for most species to become endangered or extinct
More than half of the species listed are stable or improving
Budget has been small

45. We Can Establish Wildlife Refuges and Other Protected Areas
1903: Theodore Roosevelt
Wildlife refuges
Most are wetland sanctuaries
More needed for endangered plants
Could abandoned military lands be used for wildlife habitats?
Gene or seed banks
Preserve genetic material of endangered plants
Botanical gardens and arboreta (Living plants)
Farms to raise organisms for commercial sale

46. Zoos and Aquariums Can Protect Some Species
Techniques for preserving endangered terrestrial species
Egg pulling
Captive breeding
Artificial insemination
Embryo transfer
Use of incubators
Cross-fostering
Limited space and funds
Critics say these facilities are prisons for the organisms

47. What Can You Do? Protecting Species

48. Case Study: Trying to Save the California Condor
Largest North American bird
Nearly extinct
Due to human encroachment; power line poles etc.
Birds captured and breed in captivity
By 2007, 135 released into the wild
Threatened by lead poisoning