Living in Fear: How Does Predation Affect Feeding and Investment Decisions
Faculty Mentor Name
Zachary Stahlschmidt
Research or Creativity Area
Natural Sciences
Abstract
Fear is a universal feature of animal life. Animals often experience fear when sensing a predator, which changes their behaviors. During foraging, many animals balance the risk of predation with nutritional demands, potentially resulting in their choice of a sub-optimal meal if it is safer. Stress induced by predation risk may also influence how ingested resources are invested into self-maintenance and reproduction. Here, we tested the role of predation risk in mediating pre- and post-ingestion decision-making (i.e., feeding choices and tissue allocation, respectively). We offered female variable field crickets (Gryllus lineaticeps) two food trays containing imbalanced diets: carbohydrate (C)-biased (28% C, 14% protein [P]) diet and a P-biased diet (14% C, 28 % P). We made both, one, or neither food tray “safe” by covering them with shelters. To promote fear, we pumped air scented with live predators (giant wolf spiders, Hogna carolinensis) into the crickets’ enclosures. After 5 d, we weighed crickets and later dissected them to determine investment into reproduction (ovary mass) and self-maintenance (somatic mass). We also measured the amount of P, C, and total calories that the crickets consumed. Our study will characterize how fear alters decisions related to feeding and resource investment.
Living in Fear: How Does Predation Affect Feeding and Investment Decisions
Fear is a universal feature of animal life. Animals often experience fear when sensing a predator, which changes their behaviors. During foraging, many animals balance the risk of predation with nutritional demands, potentially resulting in their choice of a sub-optimal meal if it is safer. Stress induced by predation risk may also influence how ingested resources are invested into self-maintenance and reproduction. Here, we tested the role of predation risk in mediating pre- and post-ingestion decision-making (i.e., feeding choices and tissue allocation, respectively). We offered female variable field crickets (Gryllus lineaticeps) two food trays containing imbalanced diets: carbohydrate (C)-biased (28% C, 14% protein [P]) diet and a P-biased diet (14% C, 28 % P). We made both, one, or neither food tray “safe” by covering them with shelters. To promote fear, we pumped air scented with live predators (giant wolf spiders, Hogna carolinensis) into the crickets’ enclosures. After 5 d, we weighed crickets and later dissected them to determine investment into reproduction (ovary mass) and self-maintenance (somatic mass). We also measured the amount of P, C, and total calories that the crickets consumed. Our study will characterize how fear alters decisions related to feeding and resource investment.
