Population Dynamics

1. Population Dynamics Advanced Biology – Spring 2013

2. What is a population? • Population:

3. What is a population? • Population: • All the individuals of one species in a certain area.

4. What is a population? • Population: • All the individuals of one species in a certain area. • How do we determine a population size?

5. What is a population? • Population: • All the individuals of one species in a certain area. • How do we determine a population size? • SAMPLING

6. What is a population? • Population: • All the individuals of one species in a certain area. • How do we determine a population size? • SAMPLING • CAPTURE / MARKING

7. Determining Population Size • Random Sampling:

8. Determining Population Size • Random Sampling: • Several areas are randomly chosen then you count the individuals in the given area.

9. Determining Population Size • Random Sampling: • Several areas are randomly chosen then you count the individuals in the given area. • Ex. Tree Plots

10. Determining Population Size • Random Sampling: • Several areas are randomly chosen then you count the individuals in the given area. • Ex. Tree Plots • What if your individuals move frequently?

11. Determining Population Size • Capturing / Recapture:

12. Determining Population Size • Capturing / Recapture: • Capture the animals then put a tag on them.

13. Determining Population Size • Capturing / Recapture: • Capture the animals then put a tag on them. • Recapture animals and check for difference in marked vs. unmarked.

14. Determining Population Size • Capturing / Recapture: • ASSUMPTIONS:

15. Determining Population Size • Capturing / Recapture: • ASSUMPTIONS: • No immigration / emigration

16. Determining Population Size • Capturing / Recapture: • ASSUMPTIONS: • No immigration / emigration • Each individual is able to be equally captured

17. Determining Population Size • Capturing / Recapture: • ASSUMPTIONS: • No immigration / emigration • Each individual is able to be equally captured • Catching / Marking doesn’t affect recapture

18. Determining Population Size • Capturing / Recapture: • ASSUMPTIONS: • No immigration / emigration • Each individual is able to be equally captured • Catching / Marking doesn’t affect recapture • Each sample is random

19. Determining Population Size • Capturing / Recapture: • ASSUMPTIONS: • No immigration / emigration • Each individual is able to be equally captured • Catching / Marking doesn’t affect recapture • Each sample is random • Tags can’t fall off

20. Population Distributions

21. Population Distributions • Population Dispersion:

22. Population Distributions • Population Dispersion: • The spacing of the individuals within a population.

23. Population Distributions • Population Dispersion: • The spacing of the individuals within a population. • Three Main Types:

24. Population Distributions • Population Dispersion: • The spacing of the individuals within a population. • Three Main Types: • 1. Clumped

25. Population Distributions • Population Dispersion: • The spacing of the individuals within a population. • Three Main Types: • 1. Clumped • 2. Uniform

26. Population Distributions • Population Dispersion: • The spacing of the individuals within a population. • Three Main Types: • 1. Clumped • 2. Uniform • 3. Random

27. Clumped Dispersion • Individuals live in areas of high local abundance surrounded by areas of low abundance.

28. Uniform Dispersion • Individuals are evenly spaced through out the environment.

29. Random Dispersion • Each individual has an equal probability of being anywhere.

30. Factors that affect populations • Fecundity:

31. Factors that affect populations • Fecundity: • The reproductive rate of individuals.

32. Factors that affect populations • Fecundity: • The reproductive rate of individuals. • Death Rate (mortality):

33. Factors that affect populations • Fecundity: • The reproductive rate of individuals. • Death Rate (mortality): • How often individuals die.

34. Factors that affect populations • Fecundity: • The reproductive rate of individuals. • Death Rate (mortality): • How often individuals die. • Generation Time:

35. Factors that affect populations • Fecundity: • The reproductive rate of individuals. • Death Rate (mortality): • How often individuals die. • Generation Time: • The age at which individuals can reproduce.

36. Survivorship

37. Survivorship • The percent of a group that survives to a certain age.

38. Survivorship • The percent of a group that survives to a certain age. • Three Periods:

39. Survivorship • The percent of a group that survives to a certain age. • Three Periods: • Pre-Reproductive = 0 - 15 years

40. Survivorship • The percent of a group that survives to a certain age. • Three Periods: • Pre-Reproductive = 0 - 15 years • Reproductive = 16 – 45 years

41. Survivorship • The percent of a group that survives to a certain age. • Three Periods: • Pre-Reproductive = 0 - 15 years • Reproductive = 16 – 45 years • Post-Reproductive = 46 years – death

42. Survivorship Curves • A way to graph the three stages of an animals life.

43. TYPE I – Late Loss

44. TYPE 1 – Late Loss • Reproduction early in life

45. TYPE I – Late Loss • Reproduction early in life • Low mortality rate at birth

46. TYPE I – Late Loss • Reproduction early in life • Low mortality rate at birth • High Probability of surviving to an advanced age

47. TYPE I – Late Loss • Reproduction early in life • Low mortality rate at birth • High Probability of surviving to an advanced age • Examples:

48. TYPE I – Late Loss • Reproduction early in life • Low mortality rate at birth • High Probability of surviving to an advanced age • Examples: Elephants

49. TYPE I – Late Loss • Reproduction early in life • Low mortality rate at birth • High Probability of surviving to an advanced age • Examples: Humans Elephants

50. TYPE II – Constant Loss