An increase in food availability for a species means growth. A reduction in food availability means decline. Always. Because it’s so important let me say that another way: invariably. An increase in food availability for a species means growth. A reduction means decline. Every time, ever and always. Semper et ubique. Without exception. Never otherwise. More food, growth. Less food, decline. Count on it. There is no species that dwindles in the midst of abundance, no species that thrives on nothing. This is the B of the ABCs of ecology.