Demographic effects of artificial nighttime lighting on animal populations

Artificial lighting, especially but not exclusively through street lights, has transformed the nighttime environment in much of the world. Impacts have been identified across multiple levels of biological organization and process. The influences, however, on population dynamics, particularly through the combined effects on the key demographic rates (immigration, births, deaths, emigration) that determine where individual species occur and in what numbers, have not previously been well characterized. The majority of attention explicitly on demographic parameters to date has been placed on the attraction of organisms to lights, and thus effectively local immigration, the large numbers of individuals that can be involved, and then to some extent the mortality that can often result. Some of the most important influences of nighttime lighting, however, are likely more subtle and less immediately apparent to the human observer. Particularly significant are effects of nighttime lighting on demography that act th...