New York, Aug 28 : Besides increasing noise pollution, sounding vehicle horns may also cut short lives of birds, says a research.
The findings showed that traffic noise may be associated with an increased rate of telomere loss in birds that have left the nest.
Telomeres are caps on the ends of chromosomes that protect genes from damage. Shortening of telomeres indicates accelerated biological aging.
"Our study suggests that urban noise alone, independent from the many other aspects of city life, such as light pollution or chemical pollution, is associated with increased telomere loss and may contribute to aging in Zebra finches," said Adriana Dorado-Correa, from the Max Planck Institute -- a German non-profit.
In the study, published in the journal Frontiers in Zoology, the team evaluated the impact of traffic noise exposure on a total of 263 birds by comparing telomere lengths at 21 and 120 days post-hatching under three different conditions.
They found that Zebra finches that were exposed to traffic noise after they had left the nest had shorter telomeres at 120 days of age than Zebra finches that were exposed to noise until 18 days post-hatch (before they had left the nest).
Their parents were exposed to traffic noise during courtship, egg-laying, and nesting.
The time between 18 and 120 days after hatching is a critical period during which birds are more affected by noise.
This period of time is also when Zebra finches begin song learning, which may make them more sensitive to noise.
By contrast, Zebra finches may be less sensitive to noise while still in the nest, and parent birds may be able to make behavioural changes to protect offspring from the negative effects of noise exposure.
"Cellular ageing as a result of urban stressors is something that may not have a very visible impact, but our study indicates that although birds may seem to be adapting to life in noisy cities, they may actually be ageing faster," explained co-author Sue Anne Zollinger, from the varsity.