Source of the North Pacific “boing” sound attributed to minke whales Available to Purchase

During a recent cetacean survey of the U.S. waters surrounding the Hawaiian Islands, the probable source of the mysterious “boing” sound of the North Pacific Ocean was identified as a minke whale, Balaenoptera acutorostrata. Examination of boing vocalizations from three research surveys confirms previous work that identified two distinct boing vocalization types in the North Pacific. The eastern boing $(n=22)$ has a pulse repetition rate of $92s−1$ and a duration of $3.6s$ and was found only east of $138°W$⁠. The central boing $(n=106)$ has a pulse repetition rate of $115s−1$ and a duration of approximately $2.6s$ and was found only west of $135°W$⁠. Central boing vocalizations produced by a single source $(n=84)$ indicate that variation in repetition rate and duration of the calls of the individual were not significantly different than the variation among individuals of the same boing type. Despite a slight latitudinal overlap in the vocalizations, pulse repetition rates of the eastern and central boings were distinct.