You are not logged in.
Openly accessible

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 4

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.
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 Creative Commons Attribution licence
Persistent URL http://hdl.handle.net/10536/DRO/DU:30084310

Document type: Journal Article
Collections: School of Life and Environmental Sciences
Open Access Collection
Connect to link resolver
 
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
Citation counts: TR Web of Science Citation Count  Cited 0 times in TR Web of Science
Scopus Citation Count Cited 0 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 72 Abstract Views, 4 File Downloads  -  Detailed Statistics
Created: Wed, 20 Jul 2016, 16:30:33 EST

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.