| Summary: | The cyclically-repeated song of the male humpback whale (Megaptera novaeangliae) is an important social display on their breeding grounds, functioning in male-male interactions and/or as a reproductive display to attract females. The songs are gradually synchronized into a predominant pattern shared by the majority of the singers. Transmission of songs within an ocean basin is evidently important for vocal convergence within a population and for sharing song components with other breeding populations. Songs of humpback whales have traditionally been associated with tropical or subtropical breeding grounds, however, a growing body of literature shows that songs are also sung on high-latitude feeding grounds and during migration. The purpose of the high-latitude singing is, however, not clear. This study provides detailed analyses of humpback whale songs recorded in the subarctic waters of Iceland using passive acoustic recorders collected in 2008–2009, 2009–2010, and 2011 during which singing was detected in all years. Peak song occurrence was detected during the months of January and February in all years, this timing overlaps with the timing of the peak breeding season of humpback whales in the Northern hemisphere. Songs were only detected during the winter months whereas other non-song sounds were detected throughout the year. The songs observed in Iceland were decomposed to the unit and phrase level and compared to songs recorded on traditional humpback breeding grounds in the North Atlantic, i.e. the Cape Verde in 2011–2012 and the West Indies in 2012. The aim was to investigate the purpose of singing in the subarctic and find if these songs could have a role in the cultural transmission of humpback whale songs in the North Atlantic. Markov matrices were utilised to observe the cyclical pattern and consistency of the songs in the subarctic and subtropics whereas similarity analysis (Levenshtein Distance, Levenshtein Similarity Index and Dice’s Similarity Index) were used to measure the song progression in ...
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