1. Sustaining Biodiversity: The Species Approach Pgs. 183-194
Chapter 9
Sustaining Biodiversity: The Species Approach
Pgs

2. Chapter Overview Questions
How do biologists estimate extinction rates, and how do human activities affect these rates?
Why should we care about protecting wild species?
Which human activities endanger wildlife?
How can we help prevent premature extinction of species?
What is reconciliation ecology, and how can it help prevent premature extinction of species?

3. Core 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.
Figure 11-1

4. SPECIES EXTINCTION Species can become extinct:
Locally: A species is no longer found in an area it once inhabited but is still found elsewhere in the world.
Ecologically: Occurs when so few members of a species are left they no longer play its ecological role.
Globally (biologically): Species is no longer found on the earth.

5. Global Extinction
Some animals have become prematurely extinct because of human activities.
Figure 11-2

6. Passenger pigeon Great auk Dodo Dusky seaside sparrow Aepyornis
Figure 11.2
Lost natural capital: some animal species that have become prematurely extinct largely because of human activities, mostly habitat destruction and overhunting. The Great Auk became extinct in 1844 from overhunting because of its willingness to march up the boardwalks to ships. QUESTION: Why do you think birds top this list?
Great auk
Dodo
Dusky seaside sparrow
Aepyornis
(Madagascar)
Fig. 11-2, p. 223

7. 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.
Figure 11-3

8. 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.
Fig. 11-3, p. 224

9. Swallowtail butterfly Humpback chub Golden lion tamarin Siberian tiger
Grizzly bear
Kirkland’s warbler
Knowlton cactus
Florida manatee
African elephant
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.
Utah prairie dog
Swallowtail butterfly
Humpback chub
Golden lion tamarin
Siberian tiger
Fig. 11-3, p. 224

10. Giant panda Black-footed ferret Whooping crane Northern spotted owl
Blue whale
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.
Mountain gorilla
Florida panther
California condor
Hawksbill sea turtle
Black rhinoceros
Fig. 11-3, p. 224

11. SPECIES EXTINCTION
Some species have characteristics that make them vulnerable to ecological and biological extinction.
Figure 11-4

12. Fixed migratory patterns
Characteristic
Examples
Low reproductive rate
(K-strategist)
Specialized niche
Narrow distribution
Feeds at high trophic
level
Fixed migratory patterns
Rare
Commercially valuable
Large territories
Blue whale, giant panda,
rhinoceros
Everglades kite
Many island species,
elephant seal, desert pupfish
Bengal tiger, bald eagle,
grizzly bear
Blue whale, whooping crane,
sea turtles
African violet, some orchids
Snow leopard, tiger,
elephant, rhinoceros,
rare plants and birds
California condor, grizzly
bear, Florida panther
Figure 11.4
Natural capital loss and degradation: 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?
Fig. 11-4, p. 225

13. SPECIES EXTINCTION
Scientists use measurements and models to estimate extinction rates.
The International Union for the Conservation of Nature and Natural Resources (IUCN) publishes an annual Red List, listing the world’s threatened species.
The 2004 Red List contains 15,589 species at risk for extinction.
Figure 11-5

14. SPECIES EXTINCTION
Percentage of various species types threatened with premature extinction from human activities.
Figure 11-5

15. 34% (51% of freshwater species) Fish
25%
Mammals
20%
Reptiles
Figure 11.5
Endangered natural capital: percentage of various types of species threatened with premature extinction because of human activities. QUESTION: Why do you think fish top this list? (Data from World Conservation Union, Conservation International, and World Wildlife Fund)
Plants
14%
Birds
12%
Fig. 11-5, p. 225

16. SPECIES EXTINCTION
Scientists use models to estimate the risk of particular species becoming extinct or endangered.
Figure 11-6

17. Number of years until one million
of species
existing
Effects of a 0.1% extinction rate
5,000 extinct per year
5 million
14 million
14,000 extinct per year
50 million
50,000 extinct per year
Figure 11.6
Natural capital degradation: effects of a 0.1% extinction rate.
100 million
100,000 extinct per year
Number of years until one million
species are extinct
Fig. 11-6, p. 226

18. IMPORTANCE OF WILD SPECIES
We should not cause the premature extinction of species because of the economic and ecological services they provide.
Some believe that each wild species has an inherent right to exist.
Some people distinguish between the survival rights among various types of species (plants vs. animals).

19. HABITAT LOSS, DEGRADATION, AND FRAGMENTATION
Conservation biologists summarize the most important causes of premature extinction as “HIPPO”:
Habitat destruction, degradation, and fragmentation
Invasive species
Population growth
Pollution
Overharvest

20. HABITAT LOSS, DEGRADATION, AND FRAGMENTATION
The greatest threat to a species is the loss, degradation, and fragmentation of where it lives.
Figure 11-7

21. Commercial hunting and poaching Climate change
Habitatloss
Overfishing
Pollution
Habitat degradation
and fragmentation
Commercial hunting and poaching
Climate change
Introducingnonnative species
Sale of exotic petsand decorative plants
Predator and pest control
Secondary Causes
• Population growth
• Rising resource use
• No environmental accounting
• Poverty
Figure 11.7
Natural capital degradation: underlying and direct causes of depletion and premature extinction of wild species. The major direct cause of wildlife depletion and premature extinction is habitat loss, degradation, and fragmentation. This is followed by the deliberate or accidental introduction of harmful invasive (nonnative) species into ecosystems.
Basic Causes
Fig. 11-7, p. 229

22. HABITAT LOSS, DEGRADATION, AND FRAGMENTATION
Reduction in ranges of four wildlife species, mostly due to habitat loss and overharvest.
Figure 11-8

23. Indian Tiger Range 100 years ago Range today (about 2,300 left)
Figure 11.8
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? (Data from International Union for the Conservation of Nature and World Wildlife Fund)
Range 100 years ago
Range today
(about 2,300 left)
Fig. 11-8a, p. 230

24. Black Rhino Range in 1700 Range today (about 3,600 left)
Figure 11.8
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? (Data from International Union for the Conservation of Nature and World Wildlife Fund)
Range in 1700
Range today
(about 3,600 left)
Fig. 11-8b, p. 230

25. African Elephant Probable range 1600 Range today Fig. 11-8c, p. 230
Figure 11.8
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? (Data from International Union for the Conservation of Nature and World Wildlife Fund)
Probable range 1600
Range today
Fig. 11-8c, p. 230

26. Asian or Indian Elephant
Figure 11.8
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? (Data from International Union for the Conservation of Nature and World Wildlife Fund)
Former range
Range today
(34,000–54,000 left)
Fig. 11-8d, p. 230