Question

Two species of sparrows are competing, and these species behave according to the Lotka–Volterra equations. If each individual sparrow reduces the population growth rate of its own species by 0.02 per year, and it reduces the population growth rate of the other species by 0.005 per year, then the competition coefficient is?

1) 0.005
2) 0.02
3) 0.25
4) 0.4

Answer 1

The competition coefficient in the Lotka-Volterra equations, representing the effect of one species on the population growth rate of another, is calculated as the ratio of interspecific effect to intraspecific effect. It is 0.005 divided by 0.02, equaling 0.25.

Step-by-step explanation:

The competition coefficient in the Lotka–Volterra equations represents the effect of one species on the population growth rate of another species. Since each individual sparrow of one species reduces the population growth rate of the other species by 0.005 per year, and it is known that each individual of its own species reduces its own population growth rate by 0.02, the competition coefficient (usually denoted by α for species 1 on species 2 or β for species 2 on species 1) is the ratio of these two effects. To find the competition coefficient, we divide the interspecific effect (between different species) by the intraspecific effect (within the same species).

Therefore, the competition coefficient is 0.005 (interspecific effect) divided by 0.02 (intraspecific effect), which equals 0.25. This is the measure of the competitive pressure that each sparrow exerts on the other species relative to the pressure it exerts on its own species.