Chapter 12

1. Chapter 12 Sustaining Biodiversity: The Species Approach

2. 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

3. 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.

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

5. 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

6. Fig. 11-3, p. 224

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

8. 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

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

10. 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

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

12. Human activities affect species extinction rates. • Currently extinction rates are 1,000-10,000 times higher than prehuman levels Under current extinction rates • 20% of world’s present plant and animals will be extinct by 2030 • 50% will be gone by 2099

13. Why are greater extinction rates likely? 1) Exponential population growth will increase biodiversity loss 2) Biological hot spots have extinction rates as high as 25-50% 3) Possible colonization sites are being eliminated or degraded reducing the rate of speciation. 4) A precautionary strategy to prevent significant decrease in diversity of the earth is needed.

14. Importance of wild species It will take ~5 million years for speciation to rebuild the animals & plants we will destroy in 100 years • Medicinal properties found in many plants and some animals • Recreational value/ Eco-tourism • Some people believe we should only protect some species, others believe all species have value • Remember ALL species have value, including microorganisms, and roles to play in ecosystems

15. US government animal control agents kill thousands of coyotes, prairie dogs, wolves, bobcats, and other species every year • 99% of prairie dogs in US have been extirpated • Black-footed ferret is now in trouble because it preyed on the prairie dogs

16. INVASIVE SPECIES • Many nonnative species provide us with food, medicine, and other benefits but a a few can wipe out native species, disrupt ecosystems, and cause large economic losses. Kudzu vine was introduced in the southeastern U.S. to control erosion. It has taken over native species habitats. Figure 11-A

17. INVASIVE SPECIES • Prevention is the best way to reduce threats from invasive species, because once they arrive it is almost impossible to slow their spread. Figure 11-13

18. The IUCN’s Red List is ___. • A list of ecologically damaged ecosystems • A list of species facing unusually high risk of extinction • A list of unidentified species • An identification of identified species • A scorecard of international failures at conservation

19. In general, successful introduced species experience _____. • Decreased environmental resistance • Increases in limiting factors • Increased competition from other organisms • Decreased biotic potential • Increased habitat destruction

20. Which of the following can change global species diversity. • Immigration and extirpation • Speciation and immigration • Speciation and extinction • Emigration and extinction • Extirpation and extinction

21. Which of the following can change local species diversity but not global diversity? • Immigration and extirpation • Speciation and immigration • Speciation and extinction • Emigration and extinction • Extirpation and extinction

22. Mathematical models indicate that organisms most vulnerable to habitat loss may be the • Producers • Herbivores • Decomposers • Top competitors • Bacteria

23. POPULATION GROWTH, POLLUTION, AND CLIMATE CHANGE • Population growth, affluenza, and pollution have promoted the premature extinction of some species. • Projected climate change threatens a number of species with premature extinction.

24. Pollution • Each year pesticides: • Kill about 1/5th of the U.S. honeybee colonies. • 67 million birds. • 6 -14 million fish. • Threaten 1/5th of the U.S.’s endangered and threatened species. Example of biomagnification of DDT in an aquatic food chain. Figure 11-15

25. 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.

26. Extinction threats from poaching and hunting Some protected species are killed for their valuable parts or sold to collectors live mountain gorilla= $150,000 panda pelt = $100,000 chimpanzee = $50,000 Imperial Amazon macaw = $30,000 rhinoceros horn = $13,000 per pound Bengal tiger fur= $100,000 & body parts $5,000-$20,000 What about Bushmeat?

27. OVEREXPLOITATION • Rhinoceros are often killed for their horns and sold illegally on the black market for decorative and medicinal purposes. Figure 11-16

28. Case Study: Rising Demand for Bushmeat in Africa • Bushmeat hunting has caused the local extinction of many animals in West Africa. • Can spread disease such as HIV/AIDS and ebola virus. Figure 11-17

29. Treaties help protect endangered and threatened species, but enforcement is difficult 1975 Convention on International Trade in Endangered Species (CITES) protects 900 species from being traded & restricts international trade for 29,000 species that may become threatened. Why do problem still exist? Lacey Act of 1900 prohibits transporting live or dead wild animals or their parts across state borders without a federal permit. The Endangered Species Act of 1973 identified and legally protects endangered species in the US and abroad.

30. Case Study: The U.S. Endangered Species Act • One of the world’s most far-reaching and controversial environmental laws is the 1973 U.S. Endangered Species Act (ESA). • ESA forbids federal agencies (besides defense department) to carry out / fund projects that would jeopardize an endangered species. • ESA makes it illegal for Americans to engage in commerce associated with or hunt / kill / collect endangered or threatened species.

31. Case Study: The U.S. Endangered Species Act • Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S. Figure 11-18

32. Endangered Species • Because of scarcity of inspectors, probably no more than 1/10th of the illegal wildlife trade in the U.S. is discovered. Figure 11-19

33. Endangered Species • Congress has amended the ESA to help landowners protect species on their land. • Some believe that the ESA should be weakened or repealed while others believe it should be strengthened and modified to focus on protecting ecosystems. • Many scientists believe that we should focus on protecting and sustaining biodiversity and ecosystem function as the best way to protect species.

34. PROTECTING WILD SPECIES: THE SANCTUARY APPROACH • The U.S. has set aside 544 federal refuges for wildlife, but many refuges are suffering from environmental degradation. Pelican Island was the nation’s first wildlife refuge. Figure 11-20

35. Zoos and aquariums can help protect some endangered animal species, but they are underfunded Egg pulling collects wil eggs laid by birds and hatches them in zoos Captive breeding takes wild individuals into captivity for breeding with the commitment to releasing the offspring back into the wild Artificial insemination, use of surrgate mothers, use of incubators, & cross fostering by a similar species can increase populations of rare species

36. Ultimate goal must be to reintroduce species into the wild. Reintroductions can fail because.. • There is not enough suitable habitat • Individuals bred in captivity are not able to survive in the wild. • There is renewed overhunting or capturing of the returned species. The most important role of zoos and aquariums is to educate the public.

37. RECONCILIATION ECOLOGY • Reconciliation ecology involves finding ways to share places we dominate with other species. • Replacing monoculture grasses with native species. • Maintaining habitats for insect eating bats can keep down unwanted insects. • Reduction and elimination of pesticides to protect non-target organisms (such as vital insect pollinators).

38. Using Reconciliation Ecology to Protect Bluebirds • Putting up bluebird boxes with holes too small for (nonnative) competitors in areas where trees have been cut down have helped reestablish populations. Figure 11-B

39. The blue whale is extinction prone for all of the following reasons except • Low reproduction rate • Feeding at the top trophic level • Specialized feeding habits • Fixed migratory patterns • None of these answers

40. Underlying causes of extinction and reduction of wildlife populations include all of the following except • Affluence • Human population growth • Sustainable development • Governmental policies that undervalue ecological service • Rising resource

41. Weedy pioneer species are primarily found in • Pre-Early-successional • Early-successional • Mid-successional • Late-successional • Wilderness

42. CITES is a(n) • Treaty controlling the international trade in endangered species • Set of regulations controlling the introduction of exotic species • Pact that supports critical ecosystems that support wildlife • International organization dedicated to the preservation of endangered species • All of these answers

43. Transporting of live or dead wild animals across U.S. state borders without a federal permit is prohibited by • CITES • The Endangered Species Act • The Amber Act • The Lacey Act • The Animal Preservation Act