Heart rate (f\(_H\)) and rate of oxygen ( V\(_{O2}\) consumption were recorded from adult macaroni penguins while exercising on a treadmill. No differences were found in the relationship between f\(_H\) and V\(_{O2}\) in breeding and moulting female penguins, but a significant difference was found between male and female penguins. These relationships were used to estimate field metabolic rate (FMR) for free-ranging female penguins, which were implanted with heart rate and temperature data loggers. While foraging to provision their chick, FMR was 8.92 ± 0.44 W kg\(^{-1}\) and 9.07 ± 0.42 W kg\(^{-1}\) respectively while at-sea during the brood and crèche phases of the breeding season. While on-shore, the FMR was 6.08 ± 0.43 W kg\(^{-1}\) and 5.64 ± 0.40 W kg\(^{-1}\) respectively for the brood and crèche phases. During their moult fast, male and female penguins showed a pattern of increasing and then decreasing FMR and females had a mean FMR of 5.25 ± 0.88 W kg\(^{-1}\). The peak of energy expenditure was associated with maximum feather loss, probably due to increased costs of thermoregulation. During natural diving, penguins showed complex fluctuations in heart rate. Abdominal temperature fell during dive bouts with the magnitude of this decline increasing with bout length. Put together, these adjustments in heart rate and circulation may be enough to enable all natural dives to be aerobic in nature.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:343873 |
| Date | January 2001 |
| Creators | Green, Jonathan Andrew |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/4758/ |
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