Humpback whales living on different sides of the southern Indian Ocean bellow very different songs, suggesting the behemoths don’t mingle much, or at least they aren’t freely sharing their musical material, a new study finds.
The results, published in the January issue of the journal Marine Mammal Science, give scientists more information about how culture in the form of these songs spreads among these whales that can reach lengths of 50 feet (15 meters).
Among humpback whales (Megaptera novaeangliae), males are the typical crooners, singing their tunes at a population’s winter breeding grounds, along migration routes and at summer feeding grounds. The songs consist of complex arrangements of so-called themes, which are mixes of wails, moans and shrieks that get repeated in cycles lasting up to 30 minutes, according to the researchers.
Like disc jockeys fading out one song while starting another, humpback whales also transition between song themes; these transitional “phrases” combine bits from both the preceding and subsequent themes. (A past mathematical analysis revealed just how complex these songs are, using grammatical rules to string together hours-long melodies.)
While past research has suggested humpbacks sharing the same ocean basin also share similar songs, the new study suggests that’s not the case for the two populations on both sides of the southern Indian Ocean.
2012 msnbc.com