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

This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint. You must log in to post a comment. There are no comments or no comments have been made public for this article. This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint. Add a Comment You must log in to post a comment. Comments There are no comments or no comments have been made public for this article. 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. https://doi.org/10.32942/X2X950 Life Sciences dolphin, heart rate, HRV, stress, relaxation, animal welfare, enrichment, baseline, recovery, cortisol, aquarium, husbandry Published: 2026-05-08 20:41 Last Updated: 2026-05-08 20:41 CC-By Attribution-NonCommercial-NoDerivatives 4.0 International Conflict of interest statement: The author declares no competing interests. Data and Code Availability Statement: Open data and code are not available for this preliminary protocol report because quantitative outcome data and analytical code are not presented here. The underlying records include facility- and individual-level information and will be reported separately where appropriate. Language: English