Fig. 3: Division of labour when the metabolic costs of foraging and nursing differ.
From: Resource sharing is sufficient for the emergence of division of labour

a If metabolic rates during nursing are lower relative to foraging, division of labour is reinforced. Conversely, division of labour is weaker when metabolic rates during nursing are higher than during foraging. b As their metabolic rates become lower, the nutrition level of nursing individuals deviates more strongly from those of foraging individuals. For graphical conventions, see Fig. 2.