...Michael S. Tift; Luis A. Hückstädt; Paul J. Ponganis ABSTRACT Deep-diving California sea lions ( Zalophus californianus ) can maintain arterial hemoglobin saturation ( S O 2 ) above 90% despite lung collapse (lack of gas exchange) and extremely low posterior vena caval S O 2 in the middle...

...Paul J. Ponganis; Birgitte I. McDonald; Michael S. Tift; Cassondra L. Williams ABSTRACT Recent publications have emphasized the potential generation of morbid cardiac arrhythmias secondary to autonomic conflict in diving marine mammals. Such conflict, as typified by cardiovascular responses to cold...

...Birgitte I. McDonald; Paul J. Ponganis SUMMARY The management and depletion of O 2 stores underlie the aerobic dive capacities of marine mammals. The California sea lion ( Zalophus californianus ) presumably optimizes O 2 store management during all dives, but approaches its physiological limits...

...P. J. Ponganis; T. K. Stockard; J. U. Meir; C. L. Williams; K. V. Ponganis; R. P. van Dam; R. Howard SUMMARY Blood gas analyses from emperor penguins ( Aptenodytes forsteri ) at rest, and intravascular P O 2 profiles from free-diving birds were obtained in order to examine hypoxemic tolerance...

...T. Knower Stockard; J. Heil; J. U. Meir; K. Sato; K. V. Ponganis; P. J. Ponganis SUMMARY In order to determine the rate and magnitude of respiratory O 2 depletion during dives of emperor penguins ( Aptenodytes forsteri ),air sac O 2 partial pressure ( P O 2 )was recorded in 73 dives of four birds...

... the bottom phase of the dive. To achieve this they can potentially adjust a variety of dive parameters, including dive angle and swim speed. However, because of predictable changes in buoyancy with depth,individuals would also be expected to adjust dive behavior according to dive depth. To test...

... foraging. However, empirical data indicate that the body angles of some diving animals are rarely vertical during descent and ascent. Why do they choose shallower body angles that result in longer descent and ascent durations? To investigate this question, we attached acceleration data loggers to eight...

... costs in a free-ranging marine mammal, we measured the post-dive oxygen consumption of adult Weddell seals ( N =9) performing foraging and non-foraging dives from an isolated ice hole in McMurdo Sound, Antarctica. Dives were classified according to behavior as monitored by an attached video-data logging...

...R. P. van Dam; P. J. Ponganis; K. V. Ponganis; D. H. Levenson; G. Marshall SUMMARY During diving, intermittent swim stroke patterns, ranging from burst/coast locomotion to prolonged gliding, represent potential energy conservation mechanisms that could extend the duration of aerobic metabolism...

...Scott A. Eckert SUMMARY Swim speed, dive behavior and movements were recorded for seven female leatherback sea turtles ( Dermochelys coriacea Vandelli 1761) during a single internesting interval near St Croix in the US Virgin Islands. Modal speeds ranged from 0.56 to 0.84 m s -1 , maximum speed...

...P. J. Ponganis; R. P. Van Dam; G. Marshall; T. Knower; D. H. Levenson ABSTRACT Emperor penguins ( Aptenodytes forsteri ) were equipped with a remote underwater video camera, the Crittercam, to evaluate sub-ice foraging behavior while the birds dived from an isolated dive hole. Three birds dived...

... on sea surface temperature (SST), sea surface temperature anomaly (SSTA), wind direction and speed, chlorophyll a concentrations and statistical data on fishery landings. We found that Humboldt penguins migrated by up to 895 km as marine productivity decreased. The total daily dive duration was highly...

...P. J. Ponganis; G. L. Kooyman; R. Van Dam; Y. LeMaho ABSTRACT To evaluate blood N 2 uptake and the role of the respiratory volume (air sacs/lungs) as a N 2 and O 2 reservoir in deep-diving penguins, diving respiratory volume ( V DR), heart rate ( f H), venous , blood volume ( V b ) and hemoglobin...