Heart rate during overnight rest and while diving were recorded from five emperor penguins with a microprocessor-controlled submersible recorder. Heart rate, cardiac output and stroke volume were also measured in two resting emperor penguins using standard electrocardiography and thermodilution measurements. Swim velocities from eight birds were obtained with the submersible recorder. The resting average of the mean heart rates was 72 beats min-1. Diving heart rates were about 15% lower than resting rates. Cardiac outputs of 1.9-2.9 ml kg-1 s-1 and stroke volumes of 1.6-2.7 ml kg-1 were similar to values recorded from mammals of the same body mass. Swim velocities averaged 3 m s-1. The swim speeds and heart rates suggest that muscle O2 depletion must occur frequently: therefore, many dives require a significant energy contribution from anaerobic glycolysis.
Recognising our community as we approach JEB's centenary
In this Editorial, Craig Franklin, Michaela Handel and Kathryn Knight reflect on recent developments at JEB and acknowledge the support of the community during what has been a particularly challenging year. Looking forward, they discuss the journal’s centenary celebrations in 2023.
Our Transformative Journals have exceeded their OA growth targets
In the field: an interview with Roger Hanlon
Roger Hanlon talks about his fieldwork experiences diving all over the planet to understand cephalopod camouflage and communication.
How climbing parrots achieve pitch stability while ascending
Climbing parrots push and pull with their feet on ladder rungs and push with their tails to prevent themselves from toppling backward as they ascend.
Towards understanding the neural origins of hibernation
Madeleine Junkins, Sviatoslav Bagriantsev and Elena Gracheva review the role of the nervous system in hibernation, arguing that it actively promotes and supports the hibernation process rather than simply enduring it.
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