Discoveries

January 20, 2023

The Shouting Cetaceans

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It’s not uncommon to see city folks screaming into their phones, trying to be heard over the din of traffic and road construction.

Sadly, noise pollution means that even dolphins have to “shout” to hear each other, the New York Times reported.

Dolphins communicate with each other through sound, including whistling to signal their presence to their peers.

But decades of human-made noise pollution – sourcing from shipping traffic, or oil and gas exploration for example – have made life difficult for the marine mammals.

A new study found that too much noise can also impact dolphins’ ability to communicate and cooperate with each other, for example, while hunting.

Scientists conducted a series of experiments with two dolphins at the US-based Dolphin Research Center in the Florida Keys. The two mammals were trained to swim to different parts of their habitat and press a button within one second of each other.

Researchers explained that the creatures would talk to each other using whistles, and would whistle just before pressing the button.

But as the noise increased, the team found that the cetaceans amplified their whistles, doubled the length of their calls and paid greater attention to each other’s location. These changes were necessary to compensate for the noisy environment, they added.

And the noisier it became, the more the duo’s success rate in pressing the buttons dropped.

This is the first time scientists have investigated how anthropogenic sounds can muck up animals’ ability to cooperate.

“We’re absolutely impacting animals in this way already,” said Shane Gero, a whale biologist who wasn’t involved in the study. “The unfortunate reality is that, in some ways, this story is 35 to 50 years late.”

This story originally appeared in the January 20, 2023 newsletter, Rags to Riches.