Abstract:

North Atlantic right whales (Eubalaena glacialis) produce a distinctive loud broadband signal referred to as the “gunshot” sound. Current hypotheses for the function of this signal include an agonistic threat signal between males, a mal e reproductive advertisement signal to female right whales, or a combination of both. This sound has been documented both in a social context in mixed sex surface active groups and by lone individual males in a stereotyped display. An array of five archival bottom mounted acoustic recorders was deployed in the Center of the North Atlantic Right Whale Conservation Area in the Bay of Fundy, Canada in August 2005. The five recorders were spaced 3–7 nm apart, allowing for localization of whales producing gunshot sounds within or near the array. These recordings were used to describe the regional distribution, spacing, movement patterns, and timing of gunshot sound displays produced by right whales over a two week period to investigate the potential function of this sound. Further investigations included both the diel trends in the sound production and evidence for interactions between individuals simultaneously producing these displays.