Harbor Seal (Phoca vitulina) Haul-Out Patterns Relative to Air Temperature during Summer in the San Juan Islands, Washington

Abstract

I present data taken during observations of harbor seal haul-outs and evaluate what effect temperature has on the number of seals hauled out on rocks. I propose some possibilities as to what might be influencing harbor seal behavior and haul-out preferences. Data is presented to lend evidence to the hypothesis that temperature is negatively correlated to seal numbers. Difficulty in separating temperature from other key variables, such as time of day, is addressed. Other studies are reviewed to examine congruity or lack thereof in findings and interpretations of harbor-seal haul-out patterns.