Antarctic blue whale Z-calls, and the IWC-SORP Acoustic Trends passive acoustic holdings

evidence

Antarctic blue whales produce a characteristic three-part Z-call: a first unit of 8-12 s at about 28 Hz, a short downsweep from 28 to 19 Hz, and a third unit of 8-12 s between 19 and 17 Hz, lasting up to about 18 s in total. The SORP Acoustic Trends working group had access to more than 300,000 hours of Southern Ocean passive acoustic data as of March 2020, collected over roughly twenty years from ships and moored recorders. V55 verification basis: retrieved in search summary attributed to these sources; neither paper was fetched.

A evidence is not a place. Drawing it on a map would assert something about the world that no stored fact supports.