New insights into the cardiorespiratory physiology of weaned southern elephant seals (Mirounga leonina) Cummings, Cloe R., Lea, Mary-Anne, Morrice, Margaret G., Wotherspoon, Simon and Hindell, Mark A. 2015, New insights into the cardiorespiratory physiology of weaned southern elephant seals (Mirounga leonina), Conservation physiology, vol. 3, no. 1, pp. 1-12, doi: 10.1093/conphys/cov049. Attached Files Name Description MIMEType Size Downloads morrice-newinsights-2015.pdf Published version application/pdf 1.39MB 78 Title New insights into the cardiorespiratory physiology of weaned southern elephant seals (Mirounga leonina) Formatted title New insights into the cardiorespiratory physiology of weaned southern elephant seals (Mirounga leonina) Author(s) Cummings, Cloe R. Lea, Mary-Anne Morrice, Margaret G. orcid.org/0000-0001-6903-4565 Wotherspoon, Simon Hindell, Mark A. Journal name Conservation physiology Volume number 3 Issue number 1 Start page 1 End page 12 Total pages 12 Publisher Oxford University Press Place of publication Oxford, Eng. Publication date 2015 ISSN 2051-1434 Keyword(s) chronobiology circadian rhythms generalized additive models threshold physiological response Summary Southern elephant seal (Mirounga leonina) pups must strike a balance between conserving energy during their post-weaning fast and simultaneously developing diving abilities to attain nutritional independence. Little is known about environmental influences on cardiorespiratory patterns, hence energy use, throughout the 6 week fast. Continuous heart rates were recorded for free-ranging, newly weaned southern elephant seals using heart rate time-depth recorders for 5-9 days at Sub-Antarctic Macquarie Island, during October 1994 (n = 1), 1995 (n = 4) and 1996 (n = 1). Daytime observations of respiration and behaviour were made throughout. We present the first instance of synchronous heart rate traces recorded simultaneously for individual weaners. Generalized additive models revealed that a sinusoidal pattern of diurnal heart rate elevation and nocturnal depression was evident in all seals and, on at least one occasion, a conspicuous break in this pattern coincided with an extreme cold weather event. Seals in this study were capable of considerable cardiorespiratory control and regularly demonstrated bradycardia during periods of resting apnoea. Apnoeic duration ranged from 33 to 291 s (mean 134 s). Apnoeic heart rates (mean 67 ± 15 beats min(-1), range 40-114 beats min(-1)) were on average 19.7% lower than those exhibited during periods of eupnoea (mean 83 ± 15 beats min(-1), range 44-124 beats min(-1)). The early development of the cardiorespiratory response is characterized by arrhythmic heart and respiration rates. The strong temporal patterns observed are being driven by the opposing requirements of maximizing time spent fasting in order to develop diving capabilities and of maximizing departure mass. This pilot study has highlighted a potentially large effect of ambient weather conditions on newly weaned southern elephant seal cardiorespiratory activity. Given the increasing westerlies and more erratic and increasing storminess associated with the Southern Annular Mode predicted in the Southern Ocean, the patterns observed here warrant further investigation. Language eng DOI 10.1093/conphys/cov049 Field of Research 060601 Animal Physiology - Biophysics Socio Economic Objective 970106 Expanding Knowledge in the Biological Sciences HERDC Research category C1 Refereed article in a scholarly journal ERA Research output type C Journal article Copyright notice ©2015, The Authors Free to Read? Yes Use Rights Persistent URL http://hdl.handle.net/10536/DRO/DU:30084310 Document type: Journal Article Collections: Faculty of Science, Engineering and Built Environment School of Life and Environmental Sciences Open Access Collection Related Links Link Description Connect to published version Go to link with your DU access privileges     Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved. Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact drosupport@deakin.edu.au. Versions Version Filter Type Thu, 23 Jun 2016, 11:08:46 EST Wed, 20 Jul 2016, 16:30:33 EST Thu, 21 Jul 2016, 05:01:55 EST Thu, 21 Jul 2016, 06:11:00 EST Thu, 21 Jul 2016, 10:48:40 EST Thu, 21 Jul 2016, 10:49:36 EST Fri, 26 Aug 2016, 17:33:42 EST Mon, 05 Sep 2016, 17:53:02 EST Wed, 07 Sep 2016, 11:30:36 EST Wed, 09 Nov 2016, 11:48:41 EST Mon, 06 Mar 2017, 09:41:09 EST Fri, 07 Sep 2018, 12:25:19 EST Filtered Full Citation counts:   Cited 0 times in TR Web of Science Cited 0 times in Scopus Search Google Scholar Access Statistics: 322 Abstract Views, 78 File Downloads  -  Detailed Statistics Created: Wed, 20 Jul 2016, 16:30:33 EST

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