A model to predict fasting capacities and utilization of body energy stores in weaned Steller sea lions (Eumetopias jubatus) during periods of reduced prey availability
Abbreviated Journal Title
Can. J. Zool.-Rev. Can. Zool.
NORTHERN ELEPHANT SEALS; METABOLIC-RATE; MIROUNGA-ANGUSTIROSTRIS; CALLORHINUS-URSINUS; FUR-SEAL; FORAGING BEHAVIOR; POSTWEANING FAST; DIVING BEHAVIOR; HEART-RATE; PUPS; Zoology
The population decline of Steller sea lions (Eumetopias jubatus (Schreber, 1776)) may be linked to a decline in juvenile survivorship. Limitations in prey availability may contribute to the decline, thus it is important to understand fasting capacities of Steller sea lions. For most mammals, fat catabolism is the preferred energetic pathway to ensure that protein is spared. However, marine mammals also have a conflicting requirement to conserve fat because the main site of fat storage is the blubber layer, which is also their primary thermal barrier when at sea. We developed a dynamic state variable model to demonstrate how protein and fat reserve utilization and maximum fasting duration are influenced by body condition and time spent foraging. This model was parameterized with respect to conditions faced by juvenile and subadult Steller sea lions foraging unsuccessfully during a period of reduced prey availability. The model accurately predicted changes in fat and protein mass of juvenile and subadult Steller sea lions fasting in captivity. Furthermore, the model demonstrated that body lipid content, body mass, and the proportion of time spent in water influence energy reserve catabolism and maximum fasting durations. Consequently, small, lean individuals are particularly susceptible to reductions in prey availability.
Canadian Journal of Zoology-Revue Canadienne De Zoologie
"A model to predict fasting capacities and utilization of body energy stores in weaned Steller sea lions (Eumetopias jubatus) during periods of reduced prey availability" (2009). Faculty Bibliography 2000s. 1959.