Dive heart rate in harbour porpoises is influenced by exercise and expectations
MetadataShow full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
The dive response, a decrease in heart rate (ƒH) and peripheral vasoconstriction, is the key mechanism allowing breath-hold divers to perform long duration dives. This pronounced cardiovascular response to diving has been investigated intensely in pinnipeds, but comparatively little is known for cetaceans, in particular in ecologically relevant settings. Here we studied the dive ƒH response in one the smallest cetaceans, the harbour porpoise (Phocoena phocoena). We used a novel multi-sensor data logger to record dive behaviour, ƒH, ventilations and feeding events in three trained porpoises, providing the first evaluation of cetacean ƒH regulation while performing a variety of natural behaviours, including prey capture. We predicted that tagged harbour porpoises would exhibit a decrease in ƒH in all dives, but the degree of bradycardia would be influenced by dive duration and activity, i.e., the dive ƒH response will be exercise modulated. In all dives, ƒH decreased compared to surface rates by at least 50% (mean maximum surface=173 beats min−1, mean minimum dive=50 beats min−1); however, dive ƒH was approximately 10 beats min−1 higher in active dives due to a slower decrease in ƒH and more variable ƒH during pursuit of prey. We show that porpoises exhibit the typical breath-hold diver bradycardia during aerobic dives and that the heart rate response is modulated by exercise and dive duration; however, other variables such as expectations and individual differences are equally important in determining diving heart rate.
McDonald , B , Johnson , M & Madsen , P 2018 , ' Dive heart rate in harbour porpoises is influenced by exercise and expectations ' , Journal of Experimental Biology , vol. 221 , no. 1 , jeb168740 . https://doi.org/10.1242/jeb.168740
Journal of Experimental Biology
© 2017. Published by The Company of Biologists Ltd. This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1242/jeb.168740
DescriptionThis research was supported by a National Science Foundation International Research Postdoctoral Fellowship (OISE – 1159123 awarded to B.I.M.); and grants from the Office of Naval Research (N000141410416) and the Carlsberg Foundation (awarded to P.T.M. and B.I.M.). MJ was funded by a Marie Curie Sklodowska Career Integration Grant and by the Marine Alliance for Science and Technology Scotland. Data are available from figshare digital repository at 10.6084/m9.figshare.5549329
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.