Localization of killer whale (Orcinus orca) vocalizations using a triangular hydrophone array in Johnstone Strait, British Columbia, Canada

A triangular hydrophone array was bottom‐mounted in Johnstone Strait, in summer 2006, to localize sounds emitted by individual or small groups of orcas. Spatial and temporal positioning of individual orcas was obtained from a cliff‐site observation platform; a video camera recorded surface behaviors and associations while a theodolite was used to obtain vertical and azimuthal angles needed to calculate distances to the animals. The time of arrival differences of the orca sounds at each hydrophone was used to determine the angle of arrival of the sound. Sounds were then aligned in time and space with the orcas’ corresponding movement tracks. The ability to spatially and temporally localize the vocalizations and behaviors of an isolated orca provides insight into how an individual or group of individuals may function within a matrilineal unit or pod. The objective of this study is to determine if there are defined ‘‘roles’’ in the vocal behaviors of individuals (adult males, adult females, juveniles, calves...