Bowhead whales may be the most versatile singers in the mammalian world. Recordings show that they regularly devise entirely new songs, rather than modifying existing ones.
Bowhead whales are some of the largest animals alive. They spend their lives in and around the Arctic.
of the University of Washington in Seattle and her colleagues planted hydrophones in the Fram Strait between Greenland and Svalbard, halfway between Norway and the North Pole. Over three years the hydrophones recorded 184 bowhead whale songs.
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Male bowheads do the singing. Each song lasts 45 to 150 seconds, and is repeated over and over for hours or even days. The whales mainly sing during the breeding season spanning December and January. The songs probably signal the males鈥� dominance and quality.
Versatile singers
In the recordings, some of the songs sound like power tools in action. Others resemble long, sweeping belches and snorts, sometimes with gentle whistling in the background.
The tones in bowhead songs are not restricted to single notes like human singing. 鈥淏owhead whales have the capability to produce two different sounds at once, and we don鈥檛 know how they do that,鈥� says Stafford. 鈥淭he alphabet of notes seems almost unlimited, and include the most unusual sounds.鈥�
Listen to some examples:
Changing songs
Bowhead whale song may be the most complex of any mammal, barring humans. Humpbacks are their only real whale rivals. 鈥淏lue, fin and minke whales produce much simpler songs that are more or less the same, year in, year out,鈥� says Stafford.
Bowhead songs also change more over time. 鈥淓very year, at least for this Spitsbergen group of bowheads, the songs sung in winter are completely different from previous years,鈥� says Stafford. 鈥淓ach year there are dozens of distinct songs that are not graduations from one song to another, but are completely different.鈥� She adds: 鈥淔or mammals, this is quite unique.鈥�
Humpback songs are more predictable. 鈥淗umpback whales in a population will all sing more or less the same song in the same season,鈥� says Stafford. 鈥淭hat song changes throughout the season, but most males adopt the changes鈥� The next year everyone sings something different, but made up in general of similar phrases between years.鈥�
The data could help estimate how many bowheads are left. 鈥淚f we can figure out who is singing, we could effectively census the population of singers,鈥� says Stafford. Until recently, there were only thought to be tens of Spitsbergen bowheads. However, more recent studies of all four known bowhead groups suggest they may be recovering.
Biology Letters
