1. You are an ecologist. Devise a method of estimating the number of great blue heron in Rhode Island.

2. Mark-recapture method
Scientists capture, tag, and release a random sample of individuals (s) in a population
Marked individuals are given time to mix back into the population
Scientists capture a second sample of individuals (n), and note how many of them are marked (x)
Population size (N) is estimated by sn x
N 
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3. Chapter 53
Population Ecology

4. Bioflix: population ecology

5. AP biology test formula sheet

6. Patterns of dispersion within a population's geographic range.
(a) Clumped
Patterns of dispersion within a population's geographic range.
(b) Uniform
Figure 53.4 Patterns of dispersion within a population’s geographic range.
(c) Random 6

7. What pieces of information can you glean from the life table data?
Table 53.1 Life Table for Belding’s Ground Squirrels (Spermophilus beldingi) at Tioga Pass, in the Sierra Nevada of California 7

8. What pieces of information can you glean from the life table data?

9. Survivorship Curves
A survivorship curve is a graphic way of representing the data in a life table
The survivorship curve for Belding’s ground squirrels shows a relatively constant death rate
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10. Number of survivors (log scale)
Figure 53.5
1,000
100
Number of survivors (log scale)
Females 10
Males
Figure 53.5 Survivorship curves for male and female Belding’s ground squirrels. 1 2 4 6 8 10
Age (years) 10

11. Survivorship curves can be classified into three general types
Type I: low death rates during early and middle life and an increase in death rates among older age groups
Type II: a constant death rate over the organism’s life span
Type III: high death rates for the young and a lower death rate for survivors
Many species are intermediate to these curves
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12. Number of survivors (log scale)
Figure 53.6
1,000 I
100 II
Number of survivors (log scale) 10
Figure 53.6 Idealized survivorship curves: Types I, II, and III.
III 1 50
100
Percentage of maximum life span 12

13. Reproductive Rates
For species with sexual reproduction, demographers often concentrate on females in a population
A reproductive table, or fertility schedule, is an age-specific summary of the reproductive rates in a population
It describes the reproductive patterns of a population
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14. Table 53.2
Table 53.2 Reproductive Table for Belding’s Ground Squirrels at Tioga Pass 14

15. How would an ecologist determine change in population size over a given period of time?
Devise a formula.

16. Deaths and emigration remove individuals from a population.
Population dynamics
Births
Deaths
Deaths and emigration remove individuals from a population.
Births and immigration add individuals to a population.
Figure 53.3 Population dynamics.
Immigration
Emigration 16

17. Per Capita Rate of Increase
Change in
population
size
Births
Immigrants
entering
Deaths
Emigrants
leaving   
If immigration and emigration are ignored, a population’s growth rate (per capita increase) equals birth rate minus death rate
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18. The population growth rate can be expressed mathematically as
where N is the change in population size, t is the time interval, B is the number of births, and D is the number of deaths
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19. Births and deaths can be expressed as the average number of births and deaths per individual during the specified time interval
B  bN
D  mN
where b is the annual per capita birth rate, m (for mortality) is the per capita death rate, and N is population size
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20. The population growth equation can be revised
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21. The per capita rate of increase (r) is given by
r  b  m
Zero population growth (ZPG) occurs when the birth rate equals the death rate (r  0)
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22. Change in population size can now be written as rN
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23. Instantaneous growth rate can be expressed asdN dt 
rinstN
where rinst is the instantaneous per capita rate of increase
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24. Exponential Growth
Exponential population growth is population increase under idealized conditions
d means discrete, or over a short period of time
Under these conditions, the rate of increase is at its maximum, denoted as rmax
The equation of exponential population growth is dN dt 
rmaxN
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25. Exponential population growth results in a J-shaped curve
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26. 2,000 dN dt = 1.0N 1,500 dN dt = 0.5N Population size (N) 1,000 500 5
Figure 53.7
2,000
dN dt
= 1.0N
1,500
dN dt
= 0.5N
Population size (N)
1,000
500
Figure 53.7 Population growth predicted by the exponential model. 5 10 15
Number of generations 26

27. The Logistic Growth Model
In the logistic population growth model, the per capita rate of increase declines as carrying capacity is reached
The logistic model starts with the exponential model and adds an expression that reduces per capita rate of increase as N approaches K dN dt 
(K  N) K
rmax N
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28. Table 53.3
Table 53.3 Logistic Growth of a Hypothetical Population (K = 1,500) 28

29. ( ) Exponential growth 2,000 dN dt = 1.0N 1,500 K = 1,500
Figure 53.9
Exponential growth
2,000 dN dt
= 1.0N
1,500
K = 1,500
Logistic growth dN dt (
1,500 – N
1,500 )
Population size (N)
= 1.0N
1,000
Population growth begins slowing here.
Figure 53.9 Population growth predicted by the logistic model.
500 5 10 15
Number of generations 29

30. ( ) K = carrying capacity Population size (N) dN K – N dt K = rmax N
Figure 53.UN03
K = carrying capacity
Population size (N) dN dt
K – N K ( )
= rmax N
Figure 53.UN03 Summary figure, Concept 53.3
Number of generations 30 30

31. How well do these populations fit the logistic growth model
How well do these populations fit the logistic growth model? What factor could be determining carrying capacity in each of the populations below?
1,000
180
150
800
Number of Daphnia/50 mL
120
Number of Paramecium/mL
600 90
400 60
200 30 5 10 15 20 40 60 80
100
120
140
160
Figure How well do these populations fit the logistic growth model?
Time (days)
Time (days)
(a) A Paramecium population in the lab
(b) A Daphnia population in the lab 31

32. Determining equilibrium for population density
When population density is low, b > m. As a result, the population grows until the density reaches Q.
When population density is high, m > b, and the population shrinks until the density reaches Q.
Equilibrium density (Q)
Birth or death rate per capita
Density-independent death rate (m)
Figure Determining equilibrium for population density.
Density-dependent birth rate (b)
Population density 32

33. % of young sheep producing lambs
Figure 53.16
100 80 60
% of young sheep producing lambs 40 20
Figure Decreased reproduction at high population densities.
200
300
400
500
600
Population size 33

34. Figure 53.18 50 40 30 20 10
2,500
2,000
1,500
1,000
500
Wolves
Moose
Number of wolves
Number of moose
Figure Fluctuations in moose and wolf populations on Isle Royale, 1959–2008.
1955
1965
1975
1985
1995
2005
Year 34

35. You be the ecologist

37. How could you test this hypothesis?
Hypothesis: The hare’s population cycle follows a cycle of winter food supply
How could you test this hypothesis?
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38. Hypothesis: The hare’s population cycle follows a cycle of winter food supply
If this hypothesis is correct, then the cycles should stop if the food supply is increased
Additional food was provided experimentally to a hare population, and the whole population increased in size but continued to cycle
These data do not support the first hypothesis
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.

39. How could you test this hypothesis?
Hypothesis: The hare’s population cycle is driven by pressure from other predators
How could you test this hypothesis?
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40. Hypothesis: The hare’s population cycle is driven by pressure from other predators
In a study conducted by field ecologists, 90% of the hares were killed by predators
These data support the second hypothesis
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41. Number of hares (thousands) Number of lynx (thousands)
Figure 53.19
Snowshoe hare
160
120 80 40 9 6 3
Number of hares (thousands)
Lynx
Number of lynx (thousands)
Figure Population cycles in the snowshoe hare and lynx.
1850
1875
1900
1925
Year 41

42. Hypothesis: The hare’s population cycle is linked to sunspot cycles
Sunspot activity affects light quality, which in turn affects the quality of the hares’ food
There is good correlation between sunspot activity and hare population size
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43. The results of all these experiments suggest that both predation and sunspot activity regulate hare numbers and that food availability plays a less important role
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44. Inquiry: How does food availability affect emigration and foraging in a cellular slime mold?
EXPERIMENT
Dictyostelium amoebas
Topsoil
Bacteria
200 m
Figure Inquiry: How does food availability affect emigration and foraging in a cellular slime mold?
Dictyostelium discoideum slug 44

45. ˚ Aland Islands EUROPE Occupied patch Unoccupied patch 5 km
Figure 53.21
Aland
Islands ˚
EUROPE
Figure The Glanville fritillary: a metapopulation.
Occupied patch
Unoccupied patch
5 km 45

46. Human population growth What can be said about the data?7 6 5 4 3 2 1
Human population (billions)
The Plague
Figure Human population growth (data as of 2009).
8000
BCE
4000
BCE
3000
BCE
2000
BCE
1000
BCE
1000 CE
2000 CE 46

47. Annual percent increase
Figure 53.23
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
2009
Annual percent increase
Projected data
Figure Annual percent increase in the global human population (data as of 2009).
1950
1975
2000
2025
2050
Year 47

48. Match the country with the age-structure pyramid: US, Italy, Afghanistan
United States
Italy
Male
Female
Age
85+
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
Male
Female
Age
85+
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
Male
Female
Figure Age-structure pyramids for the human population of three countries (data as of 2009). 10 8 6 4 2 2 4 6 8 10 8 6 4 2 2 4 6 8 8 6 4 2 2 4 6 8
Percent of population
Percent of population
Percent of population 48

49. How do their growths compare?
Futures Institute: Age-structure pyramids
Afghanistan
United States
Italy
Male
Female
Age
85+
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
Male
Female
Age
85+
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
Male
Female
Figure Age-structure pyramids for the human population of three countries (data as of 2009). 10 8 6 4 2 2 4 6 8 10 8 6 4 2 2 4 6 8 8 6 4 2 2 4 6 8
Percent of population
Percent of population
Percent of population 49

50. Futures Institute: Age-structure pyramids
Rapid growth
Afghanistan
Slow growth
United States
No growth
Italy
Male
Female
Age
85+
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
Male
Female
Age
85+
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
Male
Female
Figure Age-structure pyramids for the human population of three countries (data as of 2009). 10 8 6 4 2 2 4 6 8 10 8 6 4 2 2 4 6 8 8 6 4 2 2 4 6 8
Percent of population
Percent of population
Percent of population 50

51. Infant mortality (deaths per 1,000 births)
Conclusions? 60 50 40 30 20 10 80 60 40 20
Infant mortality (deaths per 1,000 births)
Life expectancy (years)
Figure Infant mortality and life expectancy at birth in industrialized and less industrialized countries (data as of 2008).
Indus- trialized countries
Less indus- trialized countries
Indus- trialized countries
Less indus- trialized countries 51

52. Gigajoules > 300 150–300 50–150 10–50 < 10 Per capita energy use
Figure Annual per capita energy use around the world.
> 300
150–300
50–150
10–50
< 10 52