Zero Population

The model may suggest what will happen if one of the species dies out. Assume that a population value less than 0.5 is essentially zero.

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 18: In the model, there are several initial conditions for which the rabbit or fox populations drop to below 0.5 at some later time. What do you observe happening to this populations after it has dropped below 0.5? Does it remain at zero?

**When the Population of either the rabbits or the foxes drop below the point of .05, the model shows that the population does not stay at zero. The model shows that once the populations of the animals fall to that low point, they are followed by a population boom. It can be said for each animal that as time increases, the intensity of the effect that each animal has on one another gets increasingly more dramatic.**

Question 19: Does this prediction make sense for a real system? Why or why not?

***The predictions of the model do make sense for a real system. According to the model, the population of the rabbits decreases as the population of the foxes increases. The population of the rabbits rises when the the population of the fox decreases. In a real system, the fox population increases because of a surplus of food(rabbits) that allows less competition which means a lower rate of death among foxes. As the fox population increases to high levels, the rabbit death rate also increases. When the rabbit population decreases because of the high death rate there is increased competition between foxes, which leads to an increase in fox death rate that allows the rabbit population to eventually increase. Barring any kind of natural disaster the system will sustain the rabbits and foxes indefinitely.

It makes sense that the population does not remain at zero and begins to climb again because in the case of a major drop in the rabbit population(where the rabbit population practically becomes zero), the fox population will lose their food source and also begin to die out which would in turn cause a rabbit population boom and the new abundance of rabbits would then cause the fox population to slowly increase. This cycle would continue as the rabbit and fox population fluctuate in response to the actuvity of the other population. When the population of the rabbits is at zero, the decrease in fox population drastically increases the possibility of survival for the rabbits which causes the population boom.
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.

I would think that the two populations are somewhat dependent on each other for survival. Obviously the foxes depend on the rabbits as their only source of food so if the rabbits died out (meaning reaching 0.0 or very close to it) the foxes should die out too because they would not have any source of food.

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