Work

Optimal diving: patch quality, depth, and marginal value

Year: 2025

Type: article

Abstract: The Marginal Value Theorem, a widely used model of how long an animal should spend foraging on a given patch, has often been invoked in the context of diving animals to predict optimal underwater foraging time. Here, we highlight and address two main issues regarding using the Marginal Value Theorem in this context. First, we show that the theorem's central assumption of diminishing returns from foraging may not always be correct or necessary, and provide an analysis demonstrating that both ecological and physiological influences on patch residency time-based on prey abundance and aerobic capacity, respectively-which have sometimes been presented as alternatives are, in fact, both important and interacting. Second, we attempt to clarify common confusions around interpreting how environmental quality should affect optimal foraging time, in the cases of homogeneous and heterogenous habitats, for which the effect of quality differ. Finally, we discuss a case in which the foraging gain depends on both foraging time and depth, and prove that the optimal foraging depth is not necessarily the depth at which the energetic rate of gain peaks. Altogether, the clarifications and general proofs we provide should improve future interpretations of models of optimal foraging in diving animals.

Source: Behavioral Ecology

DOI: 10.1093/beheco/araf141

Authors: Alasdair I Houston, Annette Fayet, John M McNamara

Institutions: University of Bristol, Norwegian Institute for Nature Research

Language: English

Topic: Marine animal studies overview

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDG: Life below water

Open Access status: hybrid

Estimated APC paid: $3,906