1. DEMOGRAPHY
The study of birth and death processes
that determine growth and age structure
of a population.

2. Each age class of a population has an expected:
Mortality rate
Fecundity rate

3. Demographic characteristics can be represented in:
Life Tables
summarize deaths and/or births
in different age classes of a population
Conventional life table

4. Cactus

5. Demographic characteristics can be represented in:
Life Tables
summarize deaths and/or births
in different age classes of a population
Conventional life table
Diagrammatic life table (flow diagram)

6. Diagrammatic Life Table
# in each age class
Fecundity
Probability of survival
(Assumes sex ratio)

7. 2) Survivorship Curves Fig. 53-6 Number of survivors (log scale) 1,000
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
Fig. 53-6

8. Imagine that a species of fish used to be a broadcast spawner (producing many eggs that then get no subsequent parental care) but has evolved to be a mouth brooder (holding the eggs in the parent’s mouth until they hatch and then caring for the young for a while). We would expect the survivorship curve of this species to shift
A) from Type I to Type II or III. B) from Type II to Type I. C) from Type III to Type I or II. D) from Type II to Type III. E) The survivorship type would vary unpredictably.

9. POPULATION DENSITY

10. Births and immigration add individuals to a population.
PopuIation size
Emigration
Deaths
Deaths and emigration remove individuals from a population.
Population
Dynamics

11. Population Density (Abundance):
# of individuals of the same species
that occur in a given area.
Knowing the population density of
a particular species is important for
conservation and management decisions.

12. White Abalone

13. Bald Eagles

14. White-tailed deer

15. Density Estimation (“Sampling”) Techniques
Census (direct counts)
Indirect counts
Sample plots or transects
Mark-recapture

16. Mark-recapture Technique:
capture and mark several, then release all
soon after, capture more, SOME of which
have marks (“recaptured”)

17. Reasoning:
Proportion of 2nd capture that are
recaptured individuals represents the
proportion marked in entire population...
R/C = M/N
M = # caught and Marked in first trapping session
C = # Caught in second trapping session
R = # marked individuals Recaptured
N = estimated Number in entire population

18. R/C = M/N
So, N = M / (R/C)
N = (M x C) / R

19. Assumptions of mark-recapture technique:
closed population (no immigration or emigration)
no births or deaths (in sampling period)
marked and unmarked individuals
equally likely to be caught in second trapping