Supplementary material from "Towards non-invasive heart rate monitoring in free-ranging cetaceans: a unipolar suction cup tag measured the heart rate of trained Risso's dolphins"

• Main Authors: Aoki, Kagari, Watanabe, Yurie, Inamori, Daiki, Funasaka, Noriko, Sakamoto, Kentaro Q.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: The Royal Society 2021
• Subjects: Physiology; FOS Biological sciences; 60801 Animal Behaviour; Killer Whale
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.5429419; https://rs.figshare.com/collections/Supplementary_material_from_Towards_non-invasive_heart_rate_monitoring_in_free-ranging_cetaceans_a_unipolar_suction_cup_tag_measured_the_heart_rate_of_trained_Risso_s_dolphins_/5429419

Heart rate monitoring in free-ranging cetaceans to understand their behavioural ecology and diving physiology is challenging. Here, we developed a simple, non-invasive method to monitor the heart rate of cetaceans in the field using an electrocardiogram-measuring device and a single suction cup equipped with an electrode. The unipolar suction cup was placed on the left lateral body surface behind the pectoral fin of Risso's dolphins and a false killer whale in captivity; their heart rate was successfully monitored. We observed large heart rate oscillations corresponding to respiration in the motionless whales during surfacing (a false killer whale, mean 47 bpm, range 20–75 bpm; Risso's dolphins, 61 ± 15 bpm, mean ± s.d., range 28–120 bpm, n = 4 individuals), which was consistent with the sinus arrhythmia pattern (eupneic tachycardia and apneic bradycardia) observed in other cetaceans. The heart rate rapidly increased to about twice the baseline just after respiration and then gradually decreased at around 20–50 s and remained relatively constant until the next breath. Furthermore, we successfully monitored the heart rate of a free-swimming Risso's dolphin. The all-in-one suction cup device is feasible for field use without restraining animals and is helpful in further understanding the diving physiology of free-ranging cetaceans.This article is part of the theme issue ‘Measuring physiology in free living animals (Part II)’.