Question

the graph shown above is from one of the most well - known and ongoing ecological studies ever performed. isle royal national park, an island on lake superior, keeps data on the populations of wolves and moose living there. the moose are a major food source for the wolves.
analyze the graph data to conclude how the moose population affects the population of wolves.
a as moose populations increase, wolf populations immediately increase.
b as wolf population falls, moose populations fall with a delayed effect.
c moose populations dont really show any relationship to wolf carrying capacity.
d the wolf carrying - capacity rises as moose populations increase, but with a delayed effect.

Explanation:

The Isle Royale wolf-moose study shows a predator-prey dynamic. Moose are the wolves' main food source, so moose population size limits the wolf carrying capacity (max sustainable wolf population). Wolf population changes lag behind moose changes because it takes time for food availability to affect wolf reproduction/survival. Option A is wrong (no immediate increase), B reverses the relationship (wolf decline affects moose, not vice versa), C is wrong (moose directly impact wolf carrying capacity). D correctly states that higher moose populations raise wolf carrying capacity with a delay.

Answer:

D. The wolf carrying-capacity rises as moose populations increase, but with a delayed effect.