Noisy roads may make birds age faster

Being around noisy traffic may make zebra finches (Taeniopygia guttata) that have left the nest age faster than birds in more rural environments, according to new research.

Researchers had known that birds in urban environments had been shown to have shorter telomeres — caps at the end of chromosomes that protect genes from damage — which is indicative of quicker biological aging. “But it was unknown so far what the causes and mechanisms are,” said Adriana Dorado-Correa, first author of the recent study, who completed the research while at the Max Planck Institute for Ornithology.

In the study published in Frontiers in Zoology, Dorado-Correa and her colleagues looked at traffic noise and its relationship with telomere length. The team had three treatment groups. One group was exposed to a sound recording of traffic noise from the moment the birds started courtship until their chicks abandoned the nests. Another group was exposed to the noise from 18 to 120 days old, which is an important learning period for the birds. A control group wasn’t exposed to traffic noise at all.

After sampling the birds’ blood, the team found that zebra finches exposed to noise after leaving the nest had shorter telomeres — although the birds that were still in the nest didn’t. “It is possible they are not acoustically sensitive as older chicks that already left the nest,” Dorado-Correa said.

This is just an early step toward understanding the effects that city noise can have on wildlife, she said. Other studies have found similar effects on great tits (Parus major) and even humans, Dorado-Correa said, and her findings may be relevant to other species as well.

“We can see with our study that anthropogenic noise alone is enough to accelerate telomere loss and may contribute to premature aging,” she said. “Nevertheless, there are many types of disturbances associated with urbanization that you cannot disentangle unless you are working in the lab. Our study is the first step to identify a causal mechanism.”

She suggests more urban studies to understand how birds are affected by thing such as noise pollution and other types of pollution.

“Studies in the cities are very important to know what’s going on there,” she said. “We need to be very precise and careful with these methods of comparison to see our contributions and changes to nature.”