The growth of the plants that the animal used for food could not keep up with the needs of the population. There was so little food for the animals, the population declined. How does this relate to carrying capacity? It does not relate to carrying capacity.

The number of animals was lower than the carrying capacity, which didn't destroy the food source and caused a population increase.

The number of animals greatly exceeded the carrying capacity, destroying the food sources and causing the population to decline.

The number of animals greatly exceeded the carrying capacity, which didn't destroy the food source and caused a population increase