Table 1. Logistic fits for a forager’s probability to exit ($P$) as a function of her crop load and the colony state.

A two-dimensional logistic function of the form $P={(1+e^{-(\alpha +\beta \cdot crop+\gamma \cdot colony)})}^{-1}$ was fit to each estimated probability to exit from Figure 6a–c. The effect of each factor is reflected in its fitted coefficient. Within each model, effects can be compared to one another because the values of $crop$ and $colony$ lay on the same scale between 0 and 1. In the constant decision rate model, all coefficients were comparable in value, indicating that $crop$ and $colony$ had similar meaningful effects on the probability to exit. In the model where decision rate was matched to interaction rate, the effect of $colony$ was weaker than the effect of $crop$, but both were still meaningful. In the model where decision rate was matched to unloading rate, the effect of $colony$ approached 0 and was very weak compared to the effect of $crop$.

Decision rate model	Factor	Coefficient	95% CI		$R^2$
Constant	Intercept	$\alpha =-1.914$	$-1.921$	$-1.906$	$0.81$
	Colony State	$\beta =-1.763$	$-1.778$	$-1.747$
	Forager’s Crop	$\gamma =-2.330$	$-2.347$	$-2.312$
Interaction Rate	Intercept	$\alpha =2.701$	$2.686$	$2.716$	$0.92$
	Colony State	$\beta =-2.199$	$-2.218$	$-2.181$
	Forager’s Crop	$\gamma =-5.810$	$-5.837$	$-5.783$
Unloading Rate	Intercept	$\alpha =-0.093$	$-0.105$	$-0.081$	$0.71$
	Colony State	$\beta =0.499$	$0.482$	$0.515$
	Forager’s Crop	$\gamma =-3.092$	$-3.115$	$-3.069$