Blood oxygen transport and depletion in diving emperor penguins

Oxygen store management underlies dive performance and is dependent on the slow heart rate and peripheral vasoconstriction of the dive response to control tissue blood flow and oxygen uptake. Prior research has revealed two major patterns of muscle myoglobin saturation profiles during dives of emperor penguins. In Type A dives, myoglobin desaturated rapidly, consistent with minimal muscle blood flow, and low tissue oxygen uptake. Type B dives, with fluctuating and slower declines in myoglobin saturation, were consistent with variable tissue blood flow patterns and tissue oxygen uptake during dives. We examined arterial and venous blood oxygen profiles to evaluate blood oxygen extraction and found two primary patterns of venous hemoglobin desaturation that complemented corresponding myoglobin saturation profiles. Type A dives had venous saturations that a) increased or plateaued for most of the dive and that only declined during the latter stages of ascent, b) often became arterialized (..., Data were collected with backpack recorders on diving emperor penguins in 2001-2008, and downloaded to computers for analysis., , # Blood oxygen transport and depletion in diving emperor penguins

Data were collected with backpack recorders on diving emperor penguins, and then downloaded to computers for processing. Research was conducted at a sea ice camp in McMurdo Sound, Antarctica in 2001-2008  (see this article and related citations for details of procedures, data collection, and prior analyses of data). There were two types of recorders: an oxygen recorder and a depth recorder.  The recorders stored time (mm dd yyyy hh:mm:ss) and depth (meters), and time (mm dd yyyy hh:mm:ss) and the partial pressure of oxygen (PO2, mm Hg). These data allowed construction of oxygen and depth profiles versus time. A given bird had either an arterial or venous oxygen electrode (one electrode per bird).  As explained in the paper, the PO2 was converted to hemoglobin saturation (%) with use of the emperor penguin O2-hemoglobin dissociation curve from Meir and Ponganis, 2009. In this paper, the profiles were sorted into three g...