Sounds interesting

One of the most dramatic and widely appreciated natural history insights of recent decades has been the recording of the songs of the male humpback whale. Humans have valued the complexity and haunting tones produced by one of the largest marine mammals. The songs have been thought to play a key role in the mating process in their winter feeding grounds, which, for the Atlantic population, occurs in the Caribbean Sea. In early spring, groups of humpback whales head from the Caribbean to spring and summer feeding grounds off the northeast coast of the US where singing is thought to cease. But new research, based on recording devices on the sea bed in areas off the northeast US, was able to record sounds from whales arriving in spring over a very large area continuously for a 25-day period. Analysis has revealed that males continue to sing frequently during the late spring following their arrival in the area. Proceedings of the Royal Society of London, series B (published online) the new recordings of humpback whale songs continuing beyond their tropical breeding grounds. Breeding in humpback whales is seasonal. Females come into oestrus during winter, and males exhibit a marked increase in spermatogenesis. Aggressive intrasexual competition among males frequently occurs during this season and singing is virtually ubiquitous throughout the species' tropical range. But the researchers believe the recording of singing in the late-spring northern feeding grounds suggests that some matings may occur here as well as in their well-established tropical sites. Although singing has also been documented on migratory routes, it has been thought to be be mostly confined to tropical breeding sites. Up until now, there have been few records of singing in high-latitude feeding areas. One report described singing in late autumn off Cape Cod, but the authors suggested that song was rare in spring and triggered in autumn by different whale groups