It's hard to be a bird in the world dominated(支配)by human beings, as it's barely possible for you to hear yourself sing. Hearing the songs of your friends would be even more difficult, and you can just forget about hearing a predator approaching.
Noise is almost everywhere, especially from traffic. Lots of the landscape in the US is within just one kilometre of a road. Therefore, it is unsurprisingly to see researchers focus on the animals living near noisy roads when they evaluate the impact of road noise on animals." The problem is that noisy roads are both noisy, and at the same time, they are roads. It's hard to separate the two, "said a biologist who worked on this subject with his team. To make sure that there is just the noise without any other effect of the road, they ran speakers through a forest where there was no road. They then built an audio phantom road at a popular stopover spot for birds to fly south for the winter.
While lots of birds were kept away by noise, the researchers found that some birds just stuck around, because they lacked strength to support the next part of their migratory journey. To eat, the birds had to look down, meaning that they were not able to notice predators. And when there was too much noise, they couldn't hear the alarm calls of other birds. The two things were sadly in conflict with each other. So they had to waste time watching for predators instead of searching for food.
Road building is increasing worldwide. But there is an easy solution to the noise problem-lowering speed limits. So next time you are driving through nature, Just slow down a little It's safer for you and the wildlife. And you can enjoy the view a little longer.
