National parks and sanctuaries are places that are kept intact — in their natural form — without human settlement and technologies causing any interference. These spots are a safe haven for the wide variety of wildlife.
However, a new study indicates that these parks are not as devoid of human activity as was believed to be the case. In fact, these areas are quite vulnerable to noise pollution, which are because of man's activities.
Noise Pollution Effecting National Parks And Animal Reserves
A group of researchers from the University of Colorado placed microphones in 492 natural protected areas and recorded sounds that are most prevalent in these regions. The study stretched many years as the researchers had to go around the country setting up the microphones and then later collect the data.
They caught natural sounds like wolves howling, birds chirping, rainfall, strong winds, rivers flowing, and even the bubbling mudpots in the Yellowstone National Park. However, they also detected man-made sounds such as jets flying, mining and logging equipment, and noisy road traffic.
Researchers analyzed the natural and man-made noises together. They discovered that in almost 63 percent of the locations noise humans produced were double of natural sounds. What is surprising is that in 21 percent of these protected areas, human noise was almost 10 times that of the natural ambient noise.
"The noise levels we found can be harmful to visitor experiences in these areas, and can be harmful to human health, and to wildlife," lead author of the study Rachel Buxton remarked.
Impact Of Noise Pollution On The Wildlife
The high level of noise humans produce near these sites disturbs the natural state of animals and birds. It is important for animals to hear the ambient sounds in the forests and parks as they rely on these to alert them of any impending danger. Similarly, predators depend on natural sounds to hunt down their prey.
"For these animals, it's literally a matter of life and death if they miss these subtle sounds of nature: the sound of a footfall or the sound of another animal breathing," biologist Kurt Fristrup explained.
Noise pollution may indirectly affect plants too, even though they do not possess the sense of hearing themselves, but depend on other animals for reproduction and pollination.
"Although plants can't hear, many animals that disperse seeds or pollinate flowers can hear, and are known to be affected by noise, resulting in indirect impacts on plants," Buxton noted.
However, scientists discovered that in some of the protected national parks, noise pollution was almost non-existent. Currently, most parks are looking to deploy some form of measures to curb noise pollution so that the wildlife remains undisturbed.
The results of the study have been published in the journal Science.