Population Ecology
Population
0. A group of individuals of the same species occupying a
given area
1. Can be described by demographics
0. Vital statistics such as size, density, distribution, and
age structure
Population Age Structure
0. Divide population into age categories
1. Population’s reproductive base includes members of the
reproductive and prereproductive age categories
Determining Population Size
2. Direct counts are most accurate but seldom feasible
3. Can sample an area, then extrapolate
4. Capturerecapture method is used for mobile species
Changes in Population Size
5. Immigration adds individuals
6. Emigration subtracts individuals
7. Births add individuals
8. Deaths subtract individuals
Zero Population Growth
2. Interval in which number of births is balanced by number
of deaths
3. Assume no change as a result of migration
4. Population size remains stable
Per Capita Rates
5. Rates per individual
6. Total number of events in a time interval divided by the
number of individuals
7. Per capita birth rate per month =
Number of births per month
Population size
r
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View Full Document8. Net reproduction per individual per unit time
9. Variable combines per capita birth and death rates
(assuming both constant)
10. Can be used to calculate rate of growth of a population
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 Spring '09
 Vanden
 Demography, Population Ecology, per capita, population size

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