1. Chapter 52 Population Ecology

2. I. Population Density, Dispersion and Demography Dynamic biological processes –Birth rates/death rates; immigration/emigration –Patterns: Clumped, Uniform, Random Demography –Life tables –Survivorship curves (figures 52.4 and 52.5) –Reproductive rates

3. LE 52-2 Population size Emigration Deaths Immigration Births

4. LE 52-3 Clumped. For many animals, such as these wolves, living in groups increases the effectiveness of hunting, spreads the work of protecting and caring for young, and helps exclude other individuals from their territory. Uniform. Birds nesting on small islands, such as these king penguins on South Georgia Island in the South Atlantic Ocean, often exhibit uniform spacing, maintained by aggressive interactions between neighbors. Random. Dandelions grow from windblown seeds that land at random and later germinate.

5. II. Life History and Natural Selection Life history variables –When reproduction begins, how often, how many Life history diversity –Semelparity (Big bang reproduction) –Iteroparity (Repeated reproduction Trade offs

6. LE 52-5 III II 100 Percentage of maximum life span Number of survivors (log scale) 0 50 1,000 100 10 1 I

7. LE 52-8 Most weedy plants, such as this dandelion, grow quickly and produce a large number of seeds, ensuring that at least some will grow into plants and eventually produce seeds themselves. Some plants, such as this coconut palm, produce a moderate number of very large seeds. The large endosperm provides nutrients for the embryo, an adaptation that helps ensure the success of a relatively large fraction of offspring.

8. III. Exponential vs. Logistic Growth Exponential –Unlimited resources Logistic –Carrying capacity

9. LE 52-10 Year Elephant population 8,000 4,000 6,000 2,000 0 1980 1960 1940 1920 1900

10. LE 52-12 Number of generations Population size (N) K = 1,500 1,500 2,000 1,000 500 15 10 5 0 0 Logistic growth Exponential growth = 1.0N dN dt = 1.0N dN dt 1,500 – N 1,500

11. LE 52-13b Time (days) Number of Daphnia/50 mL 180 0 90 20 60 40 0 60 150 120 A Daphnia population in the lab 30 80 100 120140 160

12. LE 52-13c Time (years) Number of females 80 1975 1980 40 1985 0 1990 60 A song sparrow population in its natural habitat 20 1995 2000

13. IV. Regulation of Populations Density-dependent and density- independent Dynamics of population growth -> variation Population cycles

14. LE 52-18 1960 Year Moose population size 2,500 Steady decline probably caused largely by wolf predation 2,000 1,500 1,000 500 0 1970 1980 1990 2000 Dramatic collapse caused by severe winter weather and food shortage, leading to starvation of more than 75% of the population

15. LE 52-19 1960 Year Commercial catch (kg) of male crabs (log scale) 730,000 100,000 10,000 1970 1980 1990 1950

16. LE 52-21 Year Hare population size (thousands) 1850 Snowshoe hare 0 1875 1900 1925 40 80 120 160 Lynx population size (thousands) Lynx 0 3 6 9

17. V. Human Population Figure 52.23 Regional –Demographic transition –Age structure Global Carrying Capacity

18. LE 52-22 8000 B.C. Human population (billions) 6 5 4 3 2 1 0 4000 B.C. 3000 B.C. 2000 B.C. 1000 B.C. The Plague 0 1000 A.D. 2000 A.D.

19. LE 52-22 8000 B.C. Human population (billions) 6 5 4 3 2 1 0 4000 B.C. 3000 B.C. 2000 B.C. 1000 B.C. The Plague 0 1000 A.D. 2000 A.D.

20. LE 52-25 Rapid growth Afghanistan Age Male Percent of population Female 86 42 24 68 0 45–49 40–44 35–39 30–34 25–29 20–24 15–19 10–14 5–9 0–4 85+ 80–84 75–79 70–74 65–69 60–64 55–59 50–54 Slow growth United States Age Male Percent of population Female 6 42 24 68 0 45–49 40–44 35–39 30–34 25–29 20–24 15–19 10–14 5–9 0–4 85+ 80–84 75–79 70–74 65–69 60–64 55–59 50–54 8 Decrease Italy Male Percent of population Female 6 42 24 68 0 8

21. LE 52-26 Infant mortality (deaths per 1,000 births) 50 40 30 20 10 0 Developed countries 60 Developing countries Life expectancy (years) 80 40 20 0 Developed countries 60 Developing countries