Name ______Per 1 2 3 4 5 6 7 How does the environment affect an eagle population? Purpose: The purpose of this lab is to better understand what affects population growth. Population growth is affected by different environmental factors such as: climate, food availability, parasitism, water supply, pollution, disease, and competition between other species. Factors that can limit population growth are:  Density-dependent factors (disease, competition, parasites, & food),  Density-independent factors (temperature, floods, pollution, drought, habitat disruption),  Organism interaction limiting factors (predator-prey, competition, crowding, stress), and  population growth factors. Materials:  Male eagle  Map grid  300 popcorn  Female eagle  Lake grid kernels (fish) Procedure: 1. Place the box top with map grid on your desk. 2. Put 150 popcorn kernels onto the lake grid. 3. Drop the male eagle onto the map grid. Remove the popcorn on the lake grid where the eagle landed. 4. Repeat step 2 for the female eagle. 5. Each adult eagle hunts twice a day. 6. The pair of eagles needs to catch 8 fish in a period of 3 days. If they do not catch 8 fish in a 3 day period they will die.

Data/Observations: Copy the charts on your own paper. Table 1: 150 fish, eagles hunt twice a day, eagle pair needs to catch 8 fish in a 3 day period DAY 1 2 3 4 5 6 7 8 9 # of fish caught by male # of fish caught by female # of total fish caught

Table 2: 150 fish, eagles hunt twice a day, eagle pair needs to catch 8 fish in a 3 day period, but ospreys catch 6 fish each day before eagles hunt DAY 1 2 3 4 5 6 7 8 9 # of fish caught by male # of fish caught by female # of total fish caught

Ospreys represent what type of limiting factor on the eagle population? Name ______Per 1 2 3 4 5 6 7 Table 3: A drought occurs - 150 fish, but 38 die – start with 112 fish, eagles hunt twice a day, eagle pair needs to catch 8 fish in a 3 day period DAY 1 2 3 4 5 6 7 8 9 # of fish caught by male # of fish caught by female # of total fish caught Drought represents what type of limiting factor on the eagle population? ______

Table 4: Pollution - 150 fish, but 112 die – start with 38 fish, eagles hunt twice a day, eagle pair needs to catch 8 fish in a 3 day period DAY 1 2 3 4 5 6 7 8 9 # of fish caught by male # of fish caught by female # of total fish caught Pollution represents what type of limiting factor on the eagle population? ______

Table 5: 150 fish, eagles hunt twice a day, the eagles have 2 babies – now the eagle pair needs to catch 10 fish in a 3 day period DAY 1 2 3 4 5 6 7 8 9 # of fish caught by male # of fish caught by female # of total fish caught The new babies represent what type of limiting factor on the eagle population? ______

Table 6: It is spring – fish are spawning – double the 150 fish – start with 300 fish, eagles hunt twice a day, eagle pair needs to catch 8 fish in a 3 day period DAY 1 2 3 4 5 6 7 8 9 # of fish caught by male # of fish caught by female # of total fish caught Fish spawning represents what type of limiting factor on the eagle population? Graph the total number of fish caught for all 6 data tables on one graph on a separate piece of paper. Name ______Per 1 2 3 4 5 6 7 ANALYSIS: Write the questions or answer the questions in complete sentences. 1. How might eagle predation affect the fish population over time? (Use Table 1)

2. Ospreys and eagles compete for food. What effect, if any, might the competition have on the eagle population? (Use Table 2)

3. Explain how a climate change such as a drought might or might not indirectly affect the eagle population. (Use Table 3)

4. How can a seasonal change such as a frozen lake in the winter affect the eagle population?

5. What effect, if any, does the insecticide have on the fish population? On the Eagle population? (Use Table 4)

6. Can a pollutant, such as an insecticide, affect one population in an ecosystem and not another?

7. How does an increase in the eagle population affect the fish population? How is this situation similar to the competition from osprey (Use Table 5)

8. Graph the daily number of fish caught by your eagle pairs from Table 1-6, using 6 different colored pencils. Record the number of days on the horizontal axis and the number of fish on the vertical axis.