1. Population Spacing
Describes how individuals arrange themselves within a population.

2. Growth, Stability and Decline

3. Population Size
The number of individuals in a population at a given time.
Methods of determining population size:
Direct Observation
Indirect Observation
Sampling
Mark and Recapture Studies

4. Direct Observation Counting one by one to determine the population.
Christmas Island Crabs

5. Indirect Observation
Observe signs of organisms rather than the organisms themselves.
Cliff Swallows

6. Sampling
Count the number of organisms in a small area and then multiply to find the number in the larger area.

8. Mark and Recapture Study
Total Population = # marked x # recaptured
# recaptured with marks
Sea Turtles