Figure 1

World map showing the locations of the two study areas (Newfoundland⁸⁶ and Hawaii⁴⁶) in boxes, along with other regions where one or more of the five call types have been described, representing two migration routes and two foraging grounds. From left to right on the map (excluding the study sites): Southeast Alaska, USA (foraging) where all five call types were identified and found to be stable over 36 years (1976–2012)^25,54,57; Massachusetts Bay, USA (foraging; 2008)²⁵; Angola, Africa (migration; 2012)⁶²; Harvey Bay and Byron Bay (1997, 2003, 2004, 2008), Australia (migration) where whups (called ‘wops’) were stable over 11 years⁶¹; and other locations on the East Coast of Australia (migration; 2002–2004⁵⁶; 2002–2004, 2008⁶⁷). This map was created using QGIS 3.8.3-Zanzibar (https://qgis.org/en/site/forusers/download.html) using the ESRI Ocean basemap (https://services.arcgisonline.com/ArcGIS/rest/services/Ocean/World_Ocean_Base/MapServer/tile/%7Bz%7D/%7By%7D/%7Bx%7D&zmax=20&zmin=0) accessed on October 21, 2020.