Population Dynamics: Three Types Of Population Growth (Page 4 of 4) in pdf

Population Dynamics: Three Types Of Population Growth Page 4

Investigation 3: Logistic Growth of an Elephant Population

Your task is to use the logistic model to follow the growth of an endangered elephant population in Kruger

National Park, South Africa. Step through the introductory information before beginning the mathematical

model of the population’s growth.

What problems are caused by overcrowding of elephant populations, and how did the park wardens solve

these problems?

Fill in the data chart below, for values of r

= .15 and K = 7500. Remember you will use the formula for

max

logistic growth, which you wrote down earlier.

Time

Year

1-(N/K)

dN/dt

1905

1930

1935

1940

1944

1946

1950

1996

Answer the questions below as you complete the data table.

1. What was the realized intrinsic rate of growth/increase in 1905?

2. What do you notice about the relationship between the elephant population’s growth rate and the

“unused portion of K?”

3. At what point is the population closest to its r

max

4. What assumption about the environment can we make when the population is small?

5. What do you notice about dN/dt when the population is at half its carrying capacity?

6. What could have happened as the elephant density reached K?

7. Now look at the graph of the data you collected and compare it to the data collected by the researchers.

How do the two compare to one another?

8. What are the limitations of using a simple logistic model to evaluate population growth?

Population Dynamics: Three Types Of Population Growth Page 4