Previous research has shown that only the male humpback whale sings. Image: Shutterstock.
Humpback whales change songs the way humans change fashion trends.
Ellen Garland, a PhD student at the University of Queensland, has identified 11 different types of humpback whale song, which spread from the eastern Australian population to French Polynesia. These songs change every year when the whales migrate, taking up to two years to spread across the region.
The males in a population sing the same song, which continually changes over time. Ms Garland says the length of a particular song trend is very dynamic.
“It can last a year or two in a population. It can also then be spread across the region and can last for a few years, e.g. blue song lasted from 2002-2006 in the region before evolving into the light blue song.”
This can occur through either evolutionary change over a long period time, or through revolutionary change, when the males start singing a new song. “(The song) tends to be very similar when it appears in a population and then can undergo small evolutionary changes once there.”
The differences between song types are usually very striking, with changes to the sound units used, the arrangement of the multiple differing themes and the overall arrangement of the themes changing. Ms Garland has compared them to humans with fashion trends- once someone starts a new trend, everyone follows it.
Whale music also may also have its share of trendsetters. The songs tend to travel to the east, as the eastern Australian population is the largest in the region and may have more influence than the smaller groups.
However, the songs may be changing because the males want to be different to the others around them. Previous research has shown that male whales use songs in courtship and mating, so it’s probably a good idea to have your own twist on what everyone else is singing.
