Potential vocalizations of Bryde's whales in False Bay, South Africa

Abstract

Bryde's whales are one of the lesser-known species of baleen whales that inhabit tropical and subtropical waters across the globe (Kato & Perrin, 2018). Individuals from both subspecies, Balaenoptera edeni edeni (Anderson, 1878) and B. e. brydei (Olsen, 1913), also referred to as the offshore and inshore forms (Best, 1977; Best, 2001), respectively, can be found inhabiting the waters off the South African coast (Constantine et al., 2018; Penry et al., 2016). The two subspecies designations had originally been synonymized (Junge, 1950) but were later recognized as distinct, as suggested by Rice (1998), and recently confirmed genetically (Penry et al., 2018). Bryde's whales are often misidentified as other species, and their taxonomy has yet to be well resolved (Smultea et al., 2010). Further studies of the phylogenetic relationships between geographically isolated populations of Bryde's whales, by means of differences in behavior, vocalization, and mitochondrial DNA, are required to avoid conservation risks to genetically distinct populations, such as those now faced by Rice's whale (Constantine et al., 2018; Penry et al., 2018). Aside from the issues regarding taxonomy and population abundance of isolated stocks, relatively little is known regarding the swimming behavior, migratory habits, vocalizations, and the current population trend of Bryde's whales (Constantine et al., 2018; Helble et al., 2024; Penry et al., 2016).