Project Information
From Air Sacs to Tissues: Oxygen Transfer and Utilization in Diving Emperor Penguins
Start Date:
End Date:
Part 1: Air sac-to-tissue oxygen delivery is essential to the dive capacity and foraging strategy of any penguin species as well as to flight and migration in other birds. Such transport of oxygen is dependent on the complex, highly efficient avian respiratory system (air sacs and lungs) and on the cardiovascular system. This delivery of oxygen allows emperor penguins to dive deeper than 500 meters and bar-headed geese to fly over the Himalayas. However, the physiological mechanisms underlying the transfer of oxygen from air sacs to blood and the subsequent distribution of oxygen to tissues are poorly understood. The emperor penguin is ideal for investigation of this oxygen cascade because of its body size, dive capacity, physiological data base, and the prior development of research techniques and protocols for this species. This study should provide insight into a) the mechanisms underlying the efficiency of the bird oxygen transport system, b) the physiological basis of penguin dive behavior, and the ability of penguins to adapt to environmental change, and c) perhaps, even the design of better therapeutic strategies and tools for treatment of respiratory disease. The project also includes educational exhibits and lecture programs on penguin biology at SeaWorld of San Diego. These educational programs at SeaWorld have outreach to diverse groups of grade school and high school students. Part 2: This project will examine the transport of oxygen from air sacs to tissues in a series of studies with temporarily captive emperor penguins that are free-diving at an isolated dive hole research camp in McMurdo Sound. Physiological data will be obtained with application of backpack recorders for the partial pressure of oxygen (PO2) in air sacs and/or blood, and backpack heart rate/stroke rate recorders. This experimental approach will be transformative in avian biology because it will also lay the groundwork for future investigations of air sac to lung to blood oxygen transfer during exercise of volant and cursorial birds. Four major topics are examined in this project: a) air sac oxygen distribution/depletion and the movement of air between anterior and posterior air sacs, b) anterior air sac to arterial PO2 differences and parabronchial gas exchange, c) blood oxygen transport and depletion throughout dives, and the nature of the aerobic dive limit, and d) the relationship of venous oxygen depletion patterns to both heart rate and stroke effort during dives. Specific educational outreach goals include a) short video features to be displayed in the Penguin Encounter exhibit at SeaWorld of San Diego, and b) lectures, video presentations, and pre- and post-course evaluations for student campers and participants in SeaWorld’s education programs. Underwater video for exhibits/presentations with be obtained with use of a penguin backpack camera in the Antarctic.
Person Role
Ponganis, Paul Investigator and contact
Antarctic Organisms and Ecosystems Award # 1643532
AMD - DIF Record(s)
Deployment Type
McMurdo sea ice camp field camp
Data Management Plan
Product Level:
0 (raw data)
Repository Title (link) Format(s) Status
Dryad Emperor penguin air sac oxygen CSV exists
  1. Williams, C. L., Czapanskiy, M. F., John, J. S., Leger, J. S., Scadeng, M., & Ponganis, P. J. (2020). Cervical air sac oxygen profiles in diving emperor penguins: parabronchial ventilation and the respiratory oxygen store. Journal of Experimental Biology. (doi:10.1242/jeb.230219)
  2. Ponganis, P. J. (2019). State of the art review: from the seaside to the bedside: insights from comparative diving physiology into respiratory, sleep and critical care. Thorax, 74(5), 512–518. (doi:10.1136/thoraxjnl-2018-212136)
  3. Williams, C. L., & Ponganis, P. J. (2021). Diving physiology of marine mammals and birds: the development of biologging techniques. Philosophical Transactions of the Royal Society B: Biological Sciences, 376(1830), 20200211. (doi:10.1098/rstb.2020.0211)
  4. Ponganis, P. J. (2021). A Physio-Logging Journey: Heart Rates of the Emperor Penguin and Blue Whale. Frontiers in Physiology, 12. (doi:10.3389/fphys.2021.721381)
  5. Ponganis, P. J., Williams, C. L., & Kendall-Bar, J. M. (2024). Blood oxygen transport and depletion in diving emperor penguins. Journal of Experimental Biology. (doi:10.1242/jeb.246832)
Platforms and Instruments

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