a “song” for the ladies…

The tail flukes of a humpback whale as it takes a dive on the Ningaloo Reef
NINGALOO REEF DIVE 2012 Coral Bay

An important behavioural aspect of humpback whales (Megaptera novaeangliae) is a complex vocalization by the males known as a "song". All singing whales that have been sexed, by either genital region observation or molecular analysis, have been male. Male humpback singing occurs primarily during migration en route to and at winter breeding grounds. While on their winter breeding grounds of the North West Australian coast (primarily June – November), male humpback whales produce these long sequences of structured vocalizations –

“songs” – These males may be “singing” to their ladies.

Click here for an example of humpback whale song!

One of the intriguing aspects of song is its dynamic character and may be structurally described as a succession of four to seven themes during a song session, which may last for hours and then be repeated all over again. The song undergoes change throughout the season in a given geographical winter region (such as the NW coast of Australia and Hawaii), however all whales in the region adopt the new changes, apparently through a process of vocal mimicry. Singers are typically found alone and stationary at depths of around 15-30 m, although, it has also been noted that they sing en route or occasionally while accompanying a mother-calf pair.

Various functions have been proposed for song, including sexual advertisement, the maintenance of spacing between males, the synchronization of ovulation in females, and a means for male-male assessment of each other, although the functions of song continue to be elusive.

The concentration of singing humpback whales exhibit many features typical of a “lek” mating system. Defined in simple terms, a lek is a group display of males that females attend primarily for the purpose of mating during the breeding season. Because individual males do not appear to be territorial, as would be the case on a classic lek, it has been suggested that the humpback whale mating system may be classified as a "floating lek". The broad participation of males may be interpreted as a lekking aggregation and the asynchronous singing chorus as an occurrence of resulting mutualism. The participation of many singers may attract more females to the singing “hotspot” area by a heightened signal level. Sexually mature males can benefit through access to more females while immature males may gain deferred “hotshot” benefits through increased opportunities to learn and practice the social, behavioural, and acoustical skills of singing, along with the conventions of the winter grounds, which can be applied in later years.

The humpbacks are already making their way up the Coral Coast and will be sure to make a song and a splash about it!

A humpback whale breaches full body out of the water at the Ningaloo Reef on the Coral Coast.
MIGRATION MEDIA 2013 Coral Bay.

BIBLIOGRAPHY

Dawbin, W.H. (1997)  Temporal segregation of humpback whales during migrations in Southern Hemisphere waters.  Memoirs of the Queensland Museum, 42, 105-138.

Herman, L. M., Pack, A. A., Spitz, S. S., Herman, E. Y. K., Rose, K., Hakala, S., & Deakos, M. H. (2013) Humpback whale song: Who sings? Behavioral Ecology and Sociobiology, 67(10), 1653-1663.

The Dolphin Institute (2002) Humpback Whale: Natural History and Ecology. The Dolphin Institute, viewed May 2014 <http://www.dolphin-institute.org/resource_guide/gettingtoknowhumpbackwhales.htm>.

Valsecchi, E., Hale, P., Corkeron, P., & Amos, W. (2002) Social structure in migrating humpback whales (Megaptera novaeangliae). Molecular Ecology, 11, 507-518

Winn, H.E., & Winn, L.K. (1978) The song of the humpback whale (Megaptera novaeangliae) in the West Indies.  Marine Biology, 47, 97-114.