The up-call

Right whales make a half-dozen types of sounds, but this is the one our auto-detection buoys listen for: the up-call.

The up-call is useful because it’s distinctive and right whales give it often. A type of “contact call,” the up-call is a little like small talk--the sound of a right whale going about its day and letting others know it’s nearby. In this recording the up-call is easy to hear--a deep, rising “whoop” that lasts about a second.

A noisy shipping lane can make things more complicated. Can you hear the whale call in this recording?

Probably not--but an auto-detection buoy can. Its software picks out characteristics of a whale call even while large ships are passing by. Sound spectrograms like the one above are very useful for this. Even though the whale call is almost inaudible, you can see the shape of the up-call in the graph.

How to read a spectrogram