Northern Indian Ocean blue whale songs recorded off the coast of India.

A new blue whale song-type described for the Arabian Sea and Western Indian Ocean. A comparison of sounds attributed to pygmy blue whales (Balaenoptera musculus brevicauda) recorded south of the Madagascar Plateau and those attributed to "true" blue whales (Balaenoptera musculus) recorded off Antarctica. This phenomenon of a gradual decrease in frequency of song units has been recognized in blue whale songs globally, including the Indian Ocean (Leroy et al., 2018; McDonald et al., 2009; Miksis-Olds et al., 2018). [Extracted from the article]