Sound pollution hits birds, animals’ ability to survive

By Shalini Poosarla & Akanksha Saxena
MUMBAI: Every year, the staff of The Bai Sakarbai Dinshaw Petit Hospital for Animals in Parel brace themselves for the festival season. Instead of taking time off, they’re often working at full strength. For when the Diwali firecrackers begin to fly, the animals go berserk.
The dogs start barking and hide under the beds and tables. Sometimes they stop eating.“We have to feed some of them before the evening crackers,” says Dr J C Khanna, head secretary of the Parel hospital.
Noise pollution doesn’t just affect human health. It has a huge impact on animals and birds too. For one, very high noise levels can cause deafness among animals with sensitive hearing.
TOI has been writing on various aspects of the noise problem as part of its campaign in association with Awaaz Foundation. This is the first of the reports looking at the impact it has on the ecology of the region.
“Noise can damage the nervous system of animals, increase their heart rate and stress levels,” says Dr Khanna, who advocates reducing the use of crackers during festivals, marriages and victory processions.
Some of these effects have been proven repeatedly. Compared to humans, there are far fewer studies on the effect of noise on animal behaviour and health, and most of these are concentrated in Europe and North America. But they give a good idea of some of the effects of high man-made noise levels on breeding, foraging and stress among wildlife.
A 2014 study from the University of Exeter showed how high noise affected the survival likelihood of European eels. When eels were exposed to ship noise, they were distracted and more likely to be caught by a predator. Furthermore, some had diminished spatial performance and elevated levels of stress.
The study concluded that “acoustic disturbance could have important physiological and behavioral impacts on animals, compromising life-or-death responses.”
Road and construction noise, especially in the greener fringe urban areas, are a particular source of disturbance to wildlife. Indeed, one 2005 study from the University of Virginia showed that breeding density of birds living near roads declined.
Ironically, noise is essential to animal existence, notes Isaac Kehimkar, deputy director of the Bombay Natural History Society. Animals are very sensitive to different kinds of sounds, an ability that is key to their existence, he said. Excessive noise can result in the loss of that sensitivity – and thus their ability to survive. For instance, whales and dolphins use whistles to communicate with other members of their species and use clicks to echolocate in the sea. But this communication and navigation system can be disturbed by the use of military sonar on the sea.
Some animals and birds do adapt to noisier surroundings, Kehimkar notes. “They may migrate to a more peaceful place for a while, although they will have to come back eventually if they are stray dogs or birds that survive in cities,” he said. But just because some creatures can adapt to a noisy environment doesn’t mean they’re not hurt by it.
There are few studies in India on this issue. However, pet owners have countless stories of how their cats and dogs get stressed by noise. Shruti Bakshi, a pet owner with two dogs, says her dogs, get so scared during Diwali that she gives them a homeopathic medicine to calm them down. "Joy refuses to go outside for weeks after Diwali,” Bakshi said.