J Exp Biol. 2025 Nov 4:jeb.251474. doi: 10.1242/jeb.251474. Online ahead of print.
ABSTRACT
Digestion elevates metabolism through the heat increment of feeding (HIF)-the energy expended on mechanical and biochemical processes after eating. Quantifying this cost is essential for bioenergetic models that predict energy flow and prey requirements in populations. Using breath-by-breath respirometry, we measured oxygen consumption (V˙O₂) in eight common bottlenose dolphins (Tursiops truncatus) before and after feeding standardized meals (1,659-2,658 kcal of capelin and herring). Metabolic rate rose by ∼37% above resting levels, peaking 60 minutes after feeding before returning to baseline within two hours. When scaled across the day, digestion increased daily metabolic needs by ∼8.2% of basal metabolism, was similar to values reported for Steller sea lions (Eumetopias jubatus) and harbor seals (Phoca vitulina), where HIF contributes 4-10% of daily energy expenditure. This study provides the first multi-individual estimate of HIF in dolphins and suggests that the energetic cost of digestion is a minor contribution to overall daily metabolism, refining energetic models and improving prey requirement estimates for cetaceans in the wild.
PMID:41185930 | DOI:10.1242/jeb.251474
