Impact of changing diet regimes on Steller sea lion body condition

摘要: A leading theory for the cause of decline Steller sea lions is nutritional stress, which led to chronic high juvenile mortality and possibly episodic adult mortality. Nutritional stress may have resulted from either poor quality or low abundance prey. The objective this study was determine whether we could predict shifts in body condition (i.e., mass fat content) over different seasons associated with a change diet toward lower prey). Captive (n = 3) were fed three regimes, where Diet 1 approximated Kodiak area 1970s prior documented that area, 2 species composition after had begun, 3 southeast Alaska lion population has been increasing 25 yr. All animals used still growing gained regardless diet. Body (%) varied between 13% 28%, but not consistently any regime season. Mean intake (in kg) significantly greater all during seasons. did, however, tend gain less on Diets 3, as well breeding postbreeding They also tended more winter 1, though these differences statistically significant. Thus, changing seasonal physiology appears impact than prey, provided sufficient quantity prey available. are opportunistic predators evidently able thrive variety Our results indicate capable compensating quality.