A new study from the University of Buffalo suggests that whale songs are very different from the songs performed by birds. After years of research, Dr. Eduardo Mercado has found that whale songs have a dynamic nature that signifies much more sophisticated sound production.
“The analyses in this paper suggest that we shouldn’t be thinking about whale songs as language or musical notes,” explained Dr. Mercado. “What the singers are doing seems to be much more dynamic, both within songs and across years.”
“Maybe it’s a matter of switching from thinking about whale songs as musical notes to something more freeform, like dancing.”
Most existing theories are based on the assumption that whales combine sounds, or units, into phrases to build songs that broadcast important information about their health and fitness to potential mates. From this perspective, said Dr. Mercado, single units are like individual quills in a peacock’s tail – each functionally equal and useful only as a collective.
However, according to the new study, the units of whale songs are not functionally equal. In collaboration with study co-author Professor Christina E. Perazio from the University of New England, Dr. Mercado explains that the units within whale songs are dynamic, changing through the years.
The researchers found that this unit morphing produces some units that are much less detectable than others. The findings of the study challenge previous conclusions regarding fitness. Instead, the new research supports the idea that whale songs reveal locations and movements – with each change making relevant units easier to hear across long distances.
“There are clear differences in the units when listening to whale songs from different years,” said Dr. Mercado. “They’re so different that it’s like switching from one musical genre to another. In any given year, the whales are using an altogether different set of sounds.”
Despite the irregularities, the morphing units are more likely to be random. According to Dr. Mercado, the changes appear evolutionary in nature, with the modifications adhering to a clear set of rules, such as maintaining the same pitch range as the previous unit.
The researchers said this could possibly increase the number of positions from which whales can reliably detect and track the signals. Overall, the research highlights the fact that whale songs are too sophisticated to be studied based on bird songs and other animal vocalizations.
“These labels are a bad idea,” said Dr. Mercado. “Shifts in pitch and duration might force an incorrect re-categorization of units. We might think we’re hearing something different, but the whale might be saying nothing has changed.”
“Humans are not the gold standard for distinguishing sounds, and we have to acknowledge and respect that when conducting research.”
The study is published in the journal Animal Cognition.
By Chrissy Sexton, Earth.com Staff Writer