Why do birds sing earlier and earlier?

We had been asking ourselves why birds sing earlier and earlier, and after confirming with friends that it wasn't a personal perception, we decided to search for the answer. A study revealed that we humans are the culprits, since growing noise and artificial light force birds to get up earlier.

A Growing Habit

Generally, we associate bird song with the beginning of a new day, as they usually sing at dawn, a while before the sun appears over the horizon. Historically, this has remained so, without major changes other than those of the different seasons and species. But city dwellers with light sleep, as well as those of us who sleep like gods but inhabit the early hours, have begun to notice for some time that birds are singing earlier.

The reasons for this are usually found quickly through common sense, linking global warming with heat and daylight. Other answers suggest changes in bird habits due to other climatic issues, but in reality the problem is rooted in human activity and how it interferes with that of birds.

The Study

Quickly answering why birds sing earlier, researchers from the University of Seville informed that artificial light and traffic noise are the reasons why birds are singing earlier. Urban life is dense and increasingly polluted with anthropogenic activity, with many artificial lights (billboards and LEDs, reflective surfaces, car headlights, etc.) and also a level of noise pollution that birds find harmful to their habits. The effect of noise on birds is what the researchers focused on, and after a few experiments, they found the key: levels of human activity alter the timing (and place) where birds sing.

They learned this by interfering with extra noise in the noise pollution of some streets during the early morning. Comparing the streets, the noise levels they had, and at what times birds started singing, scientists saw that many birds changed their habits or migrated to quieter streets. They explained that sound is very important for birds, as the animals' songs have reduced reach and they also find that the sound of their predators is masked by human noise pollution, leaving them exposed and in danger. Besides the danger, birds use their song to attract potential mates, as well as to warn of dangers or food.

However, since the traffic noise threshold of cities is so high, to make better use of energy and attract more potential breeding partners, birds are singing earlier or moving to different streets and areas. So put away that slingshot; the birds are not to blame.

Source: Nature World News