The rate of sexual development of birds depends on the artificial illumination of cities

For a long time, scientists have been planning studies on how artificial lighting on city streets can affect the lives and health of people, animals, and birds. At the moment, few such studies have been conducted. Recently, German scientists conducted a series of studies that showed a clear impact of artificial city light on the health of European blackbirds.

While studying the lives of thrushes, ornithologists from the Max Planck Society for Scientific Research discovered that birds that are raised in an urban environment from birth develop a reproductive system much earlier.

The European blackbird, also known as the blackbird or Turdus Merula, is common throughout Europe, the European part of Russia, and is occasionally found in the Caucasus. This is one of the most numerous species of European birds, so before starting the study, the experts chose it. If we talk about the speed of development, then in urban conditions, not only the reproductive function develops faster.

Under the rays of artificial lighting, thrushes begin to molt and sing several times faster. Researchers believe that it is city lighting that affects the development of the birds' organisms. Such a reaction can be observed not only in birds, but also in animals, the head of the study reports. It is known that for many species of European birds, the most important environmental signals are considered to be seasonal changes in the length of daylight hours. The sleep or wake cycle, the breeding cycle are daily and, accordingly, seasonal rhythms that affect the daily routine of birds. People involved in agriculture have long learned to manage birds by changing daylight hours: with the help of artificial lighting in chicken coops, it is possible to increase egg production (if the daylight hours are increased with the help of lamps).

Several birds of the blackbird species were carefully studied, and the scientists also monitored the average light intensity at night. Although the light intensity was quite low, the researchers claim that it was enough for the bird's reproductive system to begin developing earlier than expected. Over the course of ten months, ornithologists observed captured urban birds that were kept under intense artificial lighting and birds that lived in normal natural conditions. The results of the experiment pleasantly surprised the scientists: the gonads, the animal organs that produce sex cells, developed four weeks earlier in those birds that were kept under constant artificial light.

Scientists explain the results of the study by the fact that with the help of artificial light it is possible to change the seasonal rhythms of any animals, even wild ones. The birds that were under the light also changed their song activity. Ornithologists associate this feature with the fact that due to the change in the seasonal rhythm, the birds became ready to reproduce earlier.