1. Lessly Model Population Growth and Decay

2. Terms Ages – This is the ages of the animal broken into equal parts. Birth Rate – This is the rate at which babies are born at each age group. Survival Rate – This is the rate at each age group that determines how many animal survive to the next age group

3. Example Ages in years Birth Rate Survival Rate 0-300.7 3-60.40.8 6-90.60.9 9-120.80.6 12-150.20 This means that this animal will live to an age of 15 years old at most. Also when they are 0-3 years old they do not have children

4. Example Ages Birth Rate Survival RatePopulation 0-300.720 3-60.40.830 6-90.60.920 9-120.80.610 12-150.205 How many of the 0-3 year olds will survive to become 3-6 year olds? A survival rate of.7 and an age group population of 20 means that.7 x 20 =14

5. Example Ages Birth Rate Survival RatePop. 3 years later 0-300.720 3-60.40.83014 6-90.60.92024 9-120.80.61018 12-150.2056.7 x 20.8 x 30.9 x 20.6 x 10

6. To Find the Number of babies First realize the babies born over a 3 year period of time will all be between 0 and 3 years old. Since each age group has a different population and a different birth rate you will have to calculate each separately and then add them together.

7. Example Ages Birth Rate Survival RatePop. 3 years later 0-300.72033 3-60.40.83014 6-90.60.92024 9-120.80.61018 12-150.2056 0 x 20 + 0.4 x 30 + 0.6 x 20 + 0.8 x 10 + 0.2 x 5 = 33

8. Now Find the Number of Animals in Each Age Group 3 Years Later. 3 more years will be 6 years from the beginning. Follow the same steps as before but use the 3years later column to generate the populations. Even though you can’t have a part of an animal keep the decimals do not round. Do this on your own before checking it

9. Example 2 Ages Birth Rate Survival RatePop. 3 years latter 6 years later 0-300.72033 3-60.40.83014 6-90.60.92024 9-120.80.61018 12-150.2056

10. Example 2 Ages Birth Rate Survival RatePop. 3 years latter 6 years later 0-300.7203335.6 3-60.40.8301423.1 6-90.60.9202411.2 9-120.80.6101821.6 12-150.205610.8