Noise Pollution Causes Massive Problems for Wildlife Across the Globe.

Written by Rodrigo Pérez Ortega.

Scientists have long known that noise from human activities—from the roar of jet engines to the whir of ship propellors—can harm animals, stunting their growth and even scrambling their eggs. But it’s been unclear just how pervasive the problem is.

A massive analysis published today in Science reveals the impacts are far more widespread than even researchers thought. Data from 177 species that live on land and in the water reveal the vast majority are impacted by sound in some way, fundamentally altering their biology and behaviors, and causing many to die early.

“Everywhere we are, we bring in noise,” says neuroecologist Lucille Chapuis of La Trobe University, who was not involved in the study. “You can pretty much look at any species; it’s going to have an effect.”

Human-generated sound is more than a mere annoyance for wildlife. Noise pollution alters birdsong, causes spider hearts to race, and forces narwhals to abandon their foraging dives.

For some species, noise alters gene expression. In others, immune function or respiration. And in still others, how organs develop. It also changed how some animals forage, move, and try to avoid predators. Sometimes, noise affected species in opposite ways. When it came to looking at how noise affected how animals took care of their babies, for instance, some species responded to noise disruptions by increasing care, whereas others reduced it.

Different responses can even play out within a single species. When researchers played traffic noise at Western bluebird nests for 1 hour, parents sometimes failed to get food to their chicks. Yet birds nesting in continuously noisy places fed their young more as the noise got louder.

There were also situations in which one species was a winner and one was a loser. Bats, for example, hunt partly by listening for the faint rustle of prey, such as moths. When there’s noise in their environment, they take longer to find the moths, so they lose time and have to fly more, investing more energy while capturing less prey.

“Here, the bat is a clear loser,” Kunc says. “On the other hand, the moth is actually a winner because … it might be less affected by the noise.” In general, noise forced predators to work 2.5 times harder to catch one-quarter less prey.

But it’s not all good news for prey species. Shore crabs, lobsters, and other marine critters often take shelter to avoid predators, but enclosed shelters can amplify annoying noises from ships and drive them out into the open—potentially leading to more predation. That underscores the complicated impacts of sound, says Hans Slabbekoorn, an animal behavior expert at Leiden University. “The noise might not affect you, perhaps, but it will affect your prey or other species that you interact with.”

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