A METHOD FOR ESTIMATING MASS OF LARGE PINNIPEDS

Authors

  • Michael P. Haley,

    1. Biology Board of Studies, University of California at Santa Cruz, Santa Cruz, California 95064
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    • 1

      Address correspondence to: M. P. Haley, Zoology Department, University of the West Indies, Mona, Kingston 7, Jamaica, West Indies.

  • Charles J. Deutsch,

    1. Biology Board of Studies, University of California at Santa Cruz, Santa Cruz, California 95064
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  • Burney J. Le Boeuf

    1. Biology Board of Studies, University of California at Santa Cruz, Santa Cruz, California 95064
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Abstract

Fifty-two male elephant seals were weighed and photographed at Año Nuevo State Reserve, California, to establish a predictive relationship between photographically measured morphological variables (length, side area, and girth area) and body mass. Regression of mass on these variables revealed that side area, roughly equivalent to a longitudinal cross-section, was the most useful single variable for predicting mass, and that adding the other two variables to side area slightly improved the accuracy of the photogrammetric technique. Curvilinear regressions based on a power model provided the best predictive relationships. This technique may prove useful for estimating body mass of other pinnipeds.

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