Sometimes a whale just carries a tune.
Just like human beings, displays of affection win hearts among creatures of the sea.
Humpback whales, some of the largest sea mammals in the world, stand out as among those who impress their mates with ‘love songs’.
While they sound nothing like Sauti Sol, the repeated snorts, clicks, whistles, moans, grunts, blasts and shrieks delight the females and are an object of fascination for experts and laypeople alike.
Some underwater acoustic devices have, for the first time, been anchored to the bottom of the Watamu Marine Reserve to capture the love songs of the passing male whales.
For years, humpback whales have been migrating from Antarctica to warmer climates, congregating in Kenyan waters between July and August to calve and mate.
Journey back to Antarctica
After spending two months nursing their calves, the whales then make their journey back to Antarctica around September.
In East Africa, the whales travel up to 4,000 kilometres to reach Mozambique, Tanzania, or Kenya to take care of their new-borns.
Mr Michael Mwang’ombe, the marine mammal project coordinator at Watamu Marine Association (WMA), said male whales communicate through song, which to the human ear sounds more like a haunting melody.
Researchers aren’t entirely sure why whales sing, although most agree that it has something to do with courtship.
Given that the singers are male and they mainly sing during the mating season, the songs are probably used to attract females, or perhaps they are territorially used to keep away other males.
Just like our own sound of music, the whales’ songs evolve over time. Every year units and phrases are added, changed, or dropped.
The males learn songs like the verses of a human song and can remix them. And each region has its own dialect.
Social learning
Similar to the way we humans transfer language through social learning, humpbacks pass down their songs from one whale to another. Whales from diverse locations gather and learn new songs from other whales.
The music mixes different pitches and textures — from high wails to deep growls, rhythmic scratches to choruses that have a full range of emotions in the longest song performed by any animal.
“It can be compared to the development of different traditional Kenyan songs. The whales sing the same song, though some decide to modify the tunes, a sort of improvising, which is specific to an area, again like Kenyan traditional music,” said Mr Mwang’ombe.
Only underwater divers can hear the songs clearly in Watamu.
It is these sounds that marine conservationists and biologists are hoping will help them learn about humpback whale breeding sites in the South Western Indian Ocean.
Type of courtship
“There is much to learn about humpback whales and their communications, so far it is understood that male whale song improves reproductive success, and peaks around breeding time, so it’s a type of courtship. It is also believed that singing helps define territory with different whales,” he said.
Scientists from Madagascar, Mayotte, Mozambique, Tanzania, Australia, and Watamu are working together to eavesdrop on these songs using sound traps.
“We recorded the first whale song in Kenya in 2018 with a hand-held device from a vessel, for 15 minutes,” said Mr Mwang’ombe.
He said the sound traps deployed in 2020 are underwater devices anchored to the sea bed for up to two months and they record autonomously for a longer period than the handheld recorders.
According to WMA, male humpback whales sing the longest and most complex songs within the animal kingdom.
