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Understanding Population Ecology through St. Matthew Island's Reindeer Crisis

This chapter explores the dynamics of population ecology, using St. Matthew Island as a case study. In 1944, 29 reindeer were introduced to the island as a food supply, leading to unchecked growth and eventual depletion of resources. The reindeer's population suffered catastrophic decline due to resource scarcity, illustrating critical concepts such as carrying capacity and limiting factors. The chapter also discusses human population growth, resource consumption, and strategies like hunting to control overpopulated species, underscoring the importance of ecological principles in addressing these issues.

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Understanding Population Ecology through St. Matthew Island's Reindeer Crisis

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  1. PowerLecture:Chapter 45 Population Ecology

  2. Fig. 45-1, p.800

  3. Impacts, Issues: The Numbers Game • St. Matthew Island is an example of how population growth depends on limited environmental resources • In 1944, US Coast Guard was stationed on the island along with 29 reindeer, as an emergency food supply

  4. The Numbers Game • Without natural predators, reindeer population grew and depleted the island’s lichen • After a harsh winter, all but 1% of the founding herd perished - by the 1980s, no reindeer were left • Today, soaring Whitetail deer populations are overwhelming their environment in North America - damaging the habitat • Principles of Ecology help us understand population dynamics and address population-related problems such as Whitetail deer

  5. How Would You Vote? Are you a supporter of hunting as a way of controlling overpopulation of animals?

  6. Population Ecology What is a Population? Discuss the Human Population Pattern What limits Population Growth?

  7. Fig. 45-2b, p.802

  8. Fig. 45-2c, p.802

  9. Fig. 45-3b, p.803

  10. Determining Population Size • Direct counts are most accurate but seldom feasible • Capture-recapture method is used for mobile species

  11. Fig. 45-4a, p.803

  12. Fig. 45-4b, p.803

  13. Changes in Population Size • What Causes populations to change size? • Limiting Factors • Logistic Growth • Carrying Capacity

  14. Logistic Growth Graph initial carrying capacity new carrying capacity Fig. 45-8, p. 807

  15. Overshooting Capacity • What happens whtn a population overshoots its carrying capacity? Reindeer on St. Matthew’s Island Fig. 45-9, p.807

  16. Density-Dependent Controls • Limiting factors become more intense as population size increases. • What are some density dependent factors?

  17. Density-Independent Controls • Factors unaffected by population density • What would be some D-id controls?

  18. Survivorship Curves Figure 45.11 Page 809

  19. Fig. 45-11a, p.809

  20. Fig. 45-11b, p.809

  21. Fig. 45-11c, p.809

  22. Why are humans living longer now then they used to? Fig. 45-14, p.812

  23. Side-Stepping Controls • Expanded into new habitats • Agriculture increased carrying capacity; use of fossil fuels aided increase • Hygiene and medicine lessened effects of density-dependent controls

  24. Estimated size by 10,000 years ago 5 million By 1804 1 billion By 1927 2 billion By 1960 3 billion By 1974 4 billion By 1987 5 billion By 1999 6 billion Projected for 2050 8.9 billion domestication of plants, animals 9000 B.C. (about 11,000 years ago) beginning of industrial, scientific revolutions agriculturally based urban societies Fig. 45-15, p.813

  25. Resource Consumption • United States has 4.7 percent of the world’s population • Americans have a disproportionately large effect on the world’s resources • Per capita, Americans consume more resources and create more pollution than citizens of less developed nations

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