| Summary: | Some marine birds and mammals can perform dives of extraordinary duration and depth. Such dive performance is dependent on many factors, including total body oxygen (O 2 ) stores. For diving penguins, the respiratory system (air sacs and lungs) constitutes 30-50% of the total body O 2 store. To better understand the role and mechanism of parabronchial ventilation and O 2 utilization in penguins both on the surface and during the dive, we examined air sac partial pressures of O 2 (P O2 ) in emperor penguins ( Aptenodytes forsteri ) equipped with backpack P O2 recorders. Cervical air sac P O2 s at rest were lower than in other birds, while the cervical air sac to posterior thoracic air sac P O2 difference was larger. Pre-dive cervical air sac P O2 s were often greater than those at rest, but had a wide range and were not significantly different from those at rest. The maximum respiratory O 2 store and total body O 2 stores calculated with representative anterior and posterior air sac P O2 data did not differ from prior estimates. The mean calculated anterior air sac O 2 depletion rate for dives up to 11 min was approximately one-tenth that of the posterior air sacs. Low cervical air sac P O2 s at rest may be secondary to a low ratio of parabronchial ventilation to parabronchial blood O 2 extraction. During dives, overlap of simultaneously recorded cervical and posterior thoracic air sac P O2 profiles supported the concept of maintenance of parabronchial ventilation during a dive by air movement through the lungs. These files do not have any missing values. The data sets are ready for export or copy into any analysis program. Funding provided by: National Science Foundation Crossref Funder Registry ID: http://dx.doi.org/10.13039/100000001 Award Number: 1643532
|
|---|