Figure 4. The effect of inefficient precocious foraging on population decline.

This plot shows the time course of colony decline when all foragers perform equally well (dashed line) and when precocious foragers die faster than mature foragers (solid line). The effect of precocious foraging is modeled by replacing the death rate m by m = m_l R²/( ²+R²) whenever R<0 where R is the recruitment rate of foragers given in eqn (4). Parameter values are L = 2000,  = 0.25,  = .75, w = 27 000, m_l = 0.6 and ² = 0.059.