STELLER SEA LION BODY CONDITION INDICES |
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Authors: | K. W. Pitcher D. G. Calkins G. W. Pendleton |
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Affiliation: | Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, Alaska 99518, U. S. A. E-mail:;Alaska Department of Fish and Game, Division of Wildlife Conservation, P. O. Box 240020, Douglas, Alaska 99824, U. S. A. |
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Abstract: | We evaluated various measurements of mass, morphology, and blubber thickness as indices of fatness for Steller sea lions by correlation with the percentage of total body mass comprised by the sculp (%SCULP). We concluded LMD-index was the best index evaluated because it had a relatively high r 2 (0.58), had a linear relationship with %SCULP, and the intercept term was not different from O. We suggest the development of a LMD-index for otariids would likely reduce the unexplained variation in the index. We developed a multiple regression model ( r 2= 0.745, P < 0.001) for predicting %SCULP with LMD-index and functions of sex, age, and season as predictor variables. Steller sea lions < 5 yr of age had higher %SCULP values than those ≥ 5 yr. %SCULP declined with age for sea lions < 5 yr. Both younger and older males were fatter during the winter/spring period than during summer/ fall. Females of both age classes had similar %SCULP values throughout the year. Steller sea lions are relatively lean pinnipeds; estimates of blubber and total body lipids ranged from 5% to 17% of total body mass. |
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Keywords: | Steller sea lion Eumetopias jubatus condition indices body condition blubber body composition |
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