Strategy maps: Generalised giving-up densities for optimal foraging

Ecol Lett. 2023 Mar;26(3):398-410. doi: 10.1111/ele.14160. Epub 2023 Jan 31.


Finding a common currency for benefits and hazards is a major challenge in optimal foraging theory, often requiring complex computational methods. We present a new analytic approach that builds on the Marginal Value Theorem and giving-up densities while incorporating the nonlinear effect of predation risk. We map the space of all possible environments into strategy regions, each corresponding to a discrete optimal strategy. This provides a generalised quantitative measure of the trade-off between foraging rewards and hazards. This extends a classic optimal diet choice rule-of-thumb to incorporate the hazard of waiting for better resources to appear. We compare the dynamics of optimal decision-making for three foraging life-history strategies: One in which fitness accrues instantly, and two with delays before fitness benefit is accrued. Foragers with delayed-benefit strategies are more sensitive to predation risk than resource quality, as they stand to lose more fitness from a predation event than instant-accrual foragers.

Keywords: Markov decision process; diet choice; giving up density; landscape of fear; optimal foraging; stochastic dynamic programming.

Publication types

  • Letter

MeSH terms

  • Animals
  • Diet
  • Feeding Behavior*
  • Predatory Behavior*