Ethogram of short-finned pilot whale interactive behaviors directed towards human swimmers
Free-ranging short-finned pilot whales were shown to initiate a variety of interactive behaviors directed towards human swimmers. For the following examples pilot-whales.org provides underwater videos to illustrate these behaviors more in detail.
A pilot whale approaches a swimmer from a distance (5-20 m) and then swims around him in circles several times. The radius is small (< two swimmer body lengths). The whale is positioned at the water surface during its circle track, has eye contact with the swimmer and sometimes emits bubbles, call and other pulsed vocalizations.
A pilot whale frontally approaches a swimmer parallel to the water surface with the whale only a few centimeters submerged with the melon directed towards the swimmer. The swimmer is floating at the water surface. Often the whale emits clicks at high repetition rates and turns to the left or right while entering a one body length proximity to the swimmer. After changing their track to the left or right, whales have eye contact with the swimmer and emit bubbles and call vocalisations.
Belly up approach
A pilot whale frontally approaches a swimmer from a distant position (5-20 m) with a horizontal and dorsal orientation to the water surface. While reaching a close proximity to the swimmer (less than two swimmer body lengths), the whale turns belly up and emits clicks towards him. The whale glides along the whole body axis of the swimmer (distance to the swimmer is less than one body length) who is lying motionless at the water surface. While in the ventral position towards the swimmer, the whale has a stereoscopic eye contact with him.