Potential effects of short-term prey changes on sea lion physiology

摘要: Changes in the proximate composition of prey can result a nutritional imbalance individual animals, regardless total energy intake. This mechanism has been hypothesized to have contributed decline Steller sea lions (Eumetopias jubatus). Yet little is known about how otariids react physiologically short-term changes quality and availability. A series studies with young captive tested several potential links between lion health. Body (fat mass ratio) animals fed constant, maintenance-level, isocaloric diets highor low-lipid changed season, but overall was not affected by composition. The appeared prioritize maintaining core growth rates even when limited, electing deplete lipid reserves fulfill deficits, resulting relative body condition. In contrast, subject short-term, sub-maintenance utilized greater portion their losing on low prey. Experiments different ad libitum feeding regimes indicated that are readily able alter food intake levels compensate for differences content and, lesser degree, However, results also suggest decreases and/or foraging opportunities combine require than digestive capacity individual. particularly true may already be living “on edge” energetically. Sea Lions World 103 Alaska Grant College Program • AK-SG-06-01, 2006