MORTALITY RISK VS FOOD QUALITY TRADE-OFFS IN A COMMON CURRENCY - ANT PATCH PREFERENCES

Lasius pallitarsis colonies were given the choice between foraging in 2 patches that differed both in food quality and in associated mortality risk. With no risk at either patch, colonies always preferred the higher food quality patch. When mortality risk (a large Formica subnuda ant) was associated with the trial to the higher food quality patch, the use of that patch depended on the magnitude of the growth differential between feeding in risky or safe patches; the greater the benefit of feeding in the risky patch, the greater was its relative usage. Colonies valued risky patches equally to safe patches at the point where forager mortality rates were approximately offset by colony growth gain. -from Authors