Suppose That Rabbits Are the Only Prey and Food Supply

Multiple Choice

Suppose that rabbits are the only prey and food supply of foxes, and that the predator‒prey interaction follows Lotka‒Volterra dynamics. The mortality rate of foxes in the absence of rabbits is 0.1 per week, and the intrinsic growth rate of rabbits in the absence of predation is 0.2 per week. The capture efficiency is 0.002, and the efficiency at which rabbit biomass is converted into fox biomass is 0.2. If there are initially 30 foxes and 400 rabbits, the net growth rate in the fox population will be a _______ of _______ per week.

A) loss; 3
B) loss; 1.8
C) gain; 1.8
D) gain; 4.8