Dives of five freely diving ringed seals were classified into three-dimensional movement types. Horizontally convoluted dives, defined as dives with angular velocity >15°/sec, appeared to be foraging or social dives. Simple dives that did not include convoluted movements (angular velocity <10°/sec) were considered to be exploration dives. Directional dives with nearly linear horizontal travel (horizontal directionality >0.6, on a scale of 0-1) were presumed to be travel dives. Each three-dimensional dive type was observed with similar frequency in dives with two distinct time-depth profiles: V-shaped profiles in which ascent immediately followed descent, and U-shaped profiles in which >7 sec were spent at depth between descent and ascent. The lack of behavioral differences between dives with distinct time-depth profiles suggested that time-depth profiles are not a reliable means of inferring dive behaviors for ringed seals.
