Changes in vocal behavior of individual North Atlantic right whales in increased noise.

Abstract

This study investigates the impacts of anthropogenic noise exposure on the vocal behavior of individual North Atlantic right whales, a baleen whale species found in the urban coastal waters off the east coast of the United States and Canada. A non‐invasive acoustic recording tag, the Dtag, was used to record the noise levels received by individual whales and the vocalizations they produced in the Bay of Fundy, Canada. These data were used to assess the variability in the received levels (and therefore source level), duration, and frequency content of calls produced by the tagged whale in varying ambient noise conditions. A single stereotyped call type, the ‘upcall,’ was selected for these measurements. Individual whales producing multiple calls showed increases in received call amplitude and minimum frequency in increasing low‐frequency noise conditions. This is one of the first studies to document call intensity changes in baleen whales in response to short‐term changes in anthropogenic noise in their environment. This evidence for individual call modification in response to changes in background noise has implications for both descriptive studies of vocal behavior and design for passive acoustic monitoring systems for marine species.