Comparisons of beaked whale signals recorded in eastern Atlantic to known beaked whales signals

Abstract

Beaked whales are a group of more than 20 genetically confirmed species; they are very elusive and were among the least known species until a few years ago. Because of their sensitivity to sonar, an increased research effort dedicated to these species and in particular to their signals started 10 years ago. Despite this effort, the signals of many beaked whale species remain unknown. Signals of Blainville’s (Mesoplodon densirostris), Cuvier’s (Ziphius cavirostris), Gervais’ (Mesoplodon europaeus), and Northern Bottlenose Whales (Hyperoodon ampullatus) have been studied and described in different articles. The signals of three unknown species (different from the above mentioned species signals) have been reported. All seven species produce upsweep frequency modulated signals which seem species specific. In 2010, NATO Undersea Research Centre (NURC) conducted a sea-trial in Eastern Atlantic Ocean, Southwest of Portugal. Three different types of beaked whale signals were recorded. The characteristics of these signals will be presented and compared to the known signals of beaked whales. The conclusions of this analysis will be presented.