In Tilapia, studies have shown that intraspecific variation, particularly size-dependent trophic niche overlap, demonstrates how different individuals within the same species utilize different resources. Smaller individuals may overlap in their feeding niche with a different set of species or resources compared to larger individuals, effectively partitioning resources and reducing direct intraspecific competition.

A. Deer: While intraspecific competition occurs in deer (e.g., males competing for mates), they do not exhibit the same pronounced, size-dependent niche differentiation in feeding as observed in the Tilapia examples, where different life stages or sizes consistently use distinct food sources to avoid competition.

B. Pigeon: Studies involving rock pigeons suggest that exposure to competition can lead to increased selectivity and niche contraction (becoming more specialized on a particular resource), rather than expanding their niche to avoid intraspecific competition.

D. Toad: There is less evidence to suggest that toads widely use niche differentiation among individuals within a single population as a primary means of consistently reducing intraspecific competition in the same manner as the well-documented examples in Tilapia or certain birds/lizards.