Active throughout the night
Approximately 30 per cent of all vertebrates and more than 60 per cent of all invertebrates are nocturnal. The direct influence of the light source can lead to behaviour changes like disorientation, attraction, freezing or frightening. This can have direct influences on daily or seasonal moving, foraging, communication or reproduction. Insects can be irritated, e.g. by streets lights. Then, the insects perish on the street lights due to injuries most of the times. Individuals able to escape the irritation by the light needed more energy and time, which are both crucial necessities to survive for mating and for ingestion. Due to this, large amounts of insects are lost as a source of food for mammals, fish or birds. But there are also organisms, like spiders or bats using the crowds of insects on the street lights.
Evolutionary consequences of light
This ends up in a shift of species, as the balance is being disturbed due to the disadvantages of one species and the privileges of the other. Whole populations get diluted and sometimes even niches, in which alien species can develop themselves, are being created. These species spread excessively as they do not have natural predators. The rapid change of the night landscape on organisms also has might have evolutionary consequences. Some species might adjust or already have adjusted due to evolutionary reasons to the new light situation.
Projects in this field of research:
The IGB researches the topics "Impact of artificial light on fish physiology" and "Evolutionary ecological consequences of artificial light for mosquitoes and midges".
The IGB and the IZW are carrying out joint research on the topic "Effects of light pollution on obligatory nocturnal mammals (bats)".
The UFZ researches on the topic "Birds in ILluminated landscapes – BILL".