Living in urban areas may have huge impact on animals and humans' biological clock

Life in city can be a draining experience not only for humans but also for animals, researchers have claimed.

A team of Scottish scientists measured the circadian rhythms, the 24-hour cycle of biological activity, of blackbirds, who reside in the countryside and in urban areas, and found that they differed significantly.

According to the researchers, these changes to their biological rhythms could lead to more health problems and shorter lives.

The study, which was carried out by Glasgow University and the Max Planck Institute for Ornithology in Germany, also determined that living in the city made humans active for longer and less rested.

The blackbirds in the urban areas started their days earlier and ended them later than the rural blackbirds; they were active for about 40 minutes more, the Independent reported.

The researchers explained that the internal clocks of the birds that dwelled in the city were less robust and were more prone to disturbance.

They asserted that the differences in urban birds may have developed due to the artificial light and increased noise.

For the study, adult male European blackbirds were captured from Munich and a nearby rural forest.

Each one was fitted with a lightweight radio-transmitter that monitored their daily activity in the wild for 10 days before they were captured again.

The birds were then kept in light-proofed, sound-insulated chambers and their circadian rhythms were then measured.

The study has been published in the journal Proceedings of the Royal Society B.