It is well known that noise pollution affects humans. Even birds, whales and fish. But now it’s been found that it can cause stress in insects too.
There has been an abundance of studies into noise pollution, but scientists had never tested whether it triggers a stress response in insects. Until now.
No noise is good news
Every year, millions of monach butterflies in America and southern Canada search for milkweed plants to lay their eggs. Following concern over the insects dwindling habitats, conservationists have created monach-friendly areas alongside roadsides to help alleviate the problem.
After watching videos of the monach caterpillars shuddering when cars passed, Andy Davis, a conservation physiologist at the University of Georgia, wondered what effect this was having on the insect.
Davis built a custom heart monitor by fitting a small sensor onto a microphone to measure monarch larvae’s heart rates while they listened to recordings of traffic sounds in the laboratory.
Alan and his colleagues reported in Biology Letters in May, that the hearts of the caterpillars who were inundated with highway noise for two hours beat 17 percent faster than those in a silent room. However, they also found that the heart rates of the group who had been exposed to the traffic sounds non-stop during their entire 12-day larval development period returned to baseline levels afterwards.
Davis commented, that this reported desensitization could be problematic for the caterpillars when they become adults.
Each year, monach butterflies take a two-month journey to spend their winters in Mexico and during this time they have to escape predators and fight wind currents. Davis says, “What I think is happening [on roadsides] is their stress reactions get overwhelmed when they’re larvae and [could be] impaired when they travel to Mexico.”
A direct link between noisy larvae periods and mortality is unknown. However, Ryan Norris, an ecologist at the University of Guelph in Ontario, believes roadside areas almost certainly drive up the butterflies’ mortality due to collisions with cars. “There is so much potential road habitat for monarchs and other insects—it would be such a nice thing to capitalize on,” Norris says. “But you just can’t get around the traffic.”
Davis adds: “I think roads and monarchs just don’t mix.”
Our experience with noisy roads
At Echo Barrier, we understand the detrimental effect that noise can have on people’s health. That’s why we have developed our market leading products to help reduce noise and protect the community.
From providing acoustic barriers for music festivals to Genset acoustic enclosures for generators on construction sites, we have the expertise and products available to help with your acoustic needs in any situation.
And this includes supplying road and pedestrian barriers for road crews doing repairs and big infrastructure construction projects, keeping noise to a minimum.