You would have to wait much longer before the tree becomes full grown and yearly production of acorns grows to a level where it can sustain a couple of little squirrels. We would now like to figure out how many years a squirrel normally lives. This is more a guess than anything else, but come up with a guess of the number of years. Define and run an experiment to figure this out. To obtain a more scientific measure of squirrels' life expectancy, you would need to study large populations of squirrels in the wild for many years.
Some squirrels die younger and some older.
After observing many squirrels go through their life cycle, you would analyze the data and obtain some type of average. The number used in the model is based on such studies and analysis. You can now see a nice advantage of a model such as this. In a mater of minutes you can figure out the answer. Squirrels Birth Rate Let's now try to figure out the squirrels' birth rate in the model, which means the number of baby squirrels that each female squirrel will give birth to every year.