Behaviour 2019
Nutritional Needs and Predation Risk Combine to Shape Foraging Decisions in Ants
Bryce Barbee, Noa Pinter-Wollman. UCLA, Los Angeles, CA, United States

Animals constantly make decisions based on different, sometimes conflicting, needs and while facing a range of external constraints. Examining multiple constraints simultaneously can provide important insights on the priorities that animals make. Here we ask if nutritional needs influence the impact of risk on foraging behavior of ants. Ant colonies adjust their nutritional requirements to balance carbohydrates for workers and proteins for brood. Colonies further adjust foraging activity based on the presence of risk. We examine the foraging decisions of groups of Argentine ants (Linepithema humile), which differ in their nutritional needs, in the presence of risk. We starved groups for either proteins or carbohydrates and used a y-maze to determine the foraging decisions the ants make between carbohydrates and protein when risk cues are present. We find that ants are more likely to forage in risky conditions when starved for carbohydrates but not when starved for proteins. By examining the effect of multiple simultaneous constraints on foraging, we gain a realistic understanding of the decisions and preferences that animals make in a complex world.