Using super-fast accelerometry to study baleen whale calling behavior

A methods and techniques paper was published this week in the Journal of Experimental Biology this week describing the use of high-resolution accelerometers to determine the calling behavior in baleen whales from suction-cup attached tags. Acoustic tags have been used to detect whale calls, but the low frequencies of these calls have made the assignment each signal to specific individuals problematic. We used accelerometers coupled with stereo hydrophones to show that tags attached to calling fin whales show simultaneous 20 Hz signals in both the acoustic and accelerometer data streams. When a tag was deployed in the vicinity of calling fin whales, we were able to the detect the call acoustically, but not on the accelerometer. In addition, we were able to opportunistically observe the same phenomenon when a tag had fallen off of a calling whale, providing more support for the use of this technique to quantify calling behavior and call production rate in baleen whales. These data are critical for estimating the abundance and distribution of whales using passive acoustic monitoring around the world.