From repeated baseline HRV monitoring to activity-and-recovery assessment in a trained dolphin: a preliminary protocol report

Yumi Shimozato

Heart rate variability (HRV) may provide useful physiological information for welfare assessment in managed dolphins. Previous preliminary work proposed HRV analysis as a potential tool for evaluating welfare-related physiological states in dolphins. As a further step, this preliminary protocol report documents the development and initial implementation of a baseline-informed activity-and-recovery protocol conducted under routine husbandry conditions.
Repeated heart rate and HRV-related baseline recordings were collected by animal care staff over multiple days across several months while the dolphin voluntarily maintained a trained stationary posture at the water surface. Based on this baseline phase, a short protocol was implemented, consisting of a brief baseline recording, a preference-based positive activity, and a short recovery recording in the same trained posture.
This report records the protocol structure as a methodological basis for subsequent HRV-based assessment of baseline state, possible anticipatory state, activity-related physiological change, and post-activity recovery. By combining individual baseline recordings, HRV-based autonomic assessment, contextual records, non-invasive physiological measures, and prior habituation or desensitization to the measurement procedure, this framework may support future interpretation of physiological changes associated with affective state, stress responses, and recovery or relaxation processes under routine husbandry conditions.