The model may suggest how the death rate of the foxes will affect the populations.

Observe the predictions of the model for values in these ranges:

Initial # rabbits (R) between 50 and 200

Initial # foxes (F) between 50 and 200

Rabbit birth rate (B) between .04 and .07

Fox death rate (D) between .04 and .07

**Question 16:** In the model, how does the death rate of the foxes (D) affect the populations of foxes and rabbits?

**In the model the death rate of foxes has a marginal affect on both foxes and rabbits. As the foxes begin to die off we start to see a rapid increase in the number of rabbits. This suggests that the faster the death rate the greater increase we will see in the number of rabbits. This trend continues until we see the number of rabbits reach a satisfactory number to allow the number of foxes reproducing to out number the amount of foxes dying. At this point the cyclical tendency of this model begins to repeat itself with a greater number of both rabbits and foxes.**

**Question 17:** Does this prediction make sense for a real system? Why or why not?

**Yes, this prediction does make since for a real system because with foxes dying off there will be less predation of the expanding rabbit population due to the loss of foxes. However, this expansive growth of the number of rabbits will hit a maximum population that the island can host, at which point they will begin to decline in numbers.**

**NOTE: Until April 17, please answer only one of the unanswered research questions. If you have an original contribution to make on a question someone else already has answered, you may include it at any time.**