Table 1. Definition of variables.

Name	Definition
E	percent difference in the values of f and $\overline{f}$ (function of S, r, K, and Δt).
F%	failure rate of a forager; fraction of attempted interactions that failed (function of s).
f	number of failed interactions that a WF wasp makes in one foraging cycle, derived from empirical data (function of s).
$\overline{f}$	average number of failed interactions that a WF wasp makes in one foraging cycle, calculated under P (function of s).
K	probability that a forager will decide to attempt another interaction after a failure.
n	total number of attempted interactions in one foraging cycle (function of s).
P	probability distribution at a given water level over the number of successes s and number of failures f that a WF wasp will make.
r	probability that a CS wasp will refuse to interact with a WF wasp; probability that a WF wasp will make a failure (function of w).
rp	probability that a CS wasp will refuse to interact with a PF wasp; probability that a PF wasp will make a failure (function of w).
S	number of successful interactions needed for a WF wasp to completely rid its initial load of water (function of w).
Sp	number of successful interactions needed for a PF wasp to completely fill its initially empty crop (function of w).
s	number of successful interactions that a WF wasp manages to complete in one foraging cycle before either ridding its entire load or prematurely aborting (function of w).
$\overline{s}$	average number of successful interactions that a WF wasp manages to complete in one foraging cycle before either ridding its entire load or prematurely aborting, calculated under P (function of w).
sp	number of successful interactions that a PF wasp manages to complete in one foraging cycle before either filling its entire crop or prematurely aborting (function of w).
t	time needed for a forager to complete one foraging cycle (function of s).
w	common stomach water level; fraction of the common stomach that is filled with water.
$\overline{w}$	average common stomach water level taken over time.
Δt:	average time between two attempted interactions by a forager.
Δw	fraction of one crop load of water that a WF wasp is able to transfer to an accepting CS wasp (function of w).
σ	curvature parameter for the function r.