British scientists studying the birds believe that the light confuses the biological clocks of the birds so that they stay awake at night. They noticed that the song of robins can be heard not just in the day but also throughout the night in many cities.
Dr Davide Dominoni of Glasgow University said “I live in Glasgow now and I hear robins singing throughout the night, singing all the time.” The robins can also be heard singing in the daytime as normal though, leading researchers to question when they actually sleep. It appears as though are awake all of the time, which is almost certainly harmful to their health.
The myriad of neon signs today make shop windows look bright and attractive, throwing a distinctive glow onto the pavements. Robins are known to be affected by light in general but are particularly sensitive to blue light, however. This is the primary frequency emitted by neon signs.
Dr Dominoni has already shown what can happen when robins are exposed to lights at night in a lab setting. Some genes became active at the wrong time of the day. The concern is that robins are being led to sing at night and are using up too much energy in the process.
Dominoni told the American Association for the Advancement of Science “There have been a couple of studies suggesting they are increasing their song output at night, during the day they are still singing. Singing is a costly behaviour, it takes energy. So by increasing their song output, there might be some energetic costs.”
The effects have also been noticed in other bird species including blackbirds and seagulls. Seagulls in particular have become very noisy during the night and there have been reports of people getting annoyed by their constant squawking during the night.
It is not yet known how the problem can be resolved. Clearly, it will be hard to eliminate the issue of the light pollution so more research may be required to determine exactly how the birds are affected by the constant glow.
