Thomas W. Davies

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Since the 1970s nighttime satellite images of the Earth from space have provided a striking illustration of the extent of artificial light. Meanwhile, growing awareness of adverse impacts of artificial light at night on scientific astronomy, human health, ecological processes and aesthetic enjoyment of the night sky has led to recognition of light pollution(More)
The ecological impacts of nighttime light pollution have been a longstanding source of concern, accentuated by realized and projected growth in electrical lighting. As human communities and lighting technologies develop, artificial light increasingly modifies natural light regimes by encroaching on dark refuges in space, in time, and across wavelengths. A(More)
1. Much concern has been expressed about the ecological consequences of night-time light pollution. This concern is most often focused on the encroachment of artificial light into previously unlit areas of the night-time environment, but changes in the spectral composition, duration and spatial pattern of light are also recognized as having ecological(More)
Artificial light at night is profoundly altering natural light cycles, particularly as perceived by many organisms, over extensive areas of the globe. This alteration comprises the introduction of light at night at places and times at which it has not previously occurred, and with different spectral signatures. Given the long geological periods for which(More)
Despite constituting a widespread and significant environmental change, understanding of artificial nighttime skyglow is extremely limited. Until now, published monitoring studies have been local or regional in scope, and typically of short duration. In this first major international compilation of monitoring data we answer several key questions about(More)
Artificial lighting has been used to illuminate the nocturnal environment for centuries and continues to expand with urbanization and economic development. Yet, the potential ecological impact of the resultant light pollution has only recently emerged as a major cause for concern. While investigations have demonstrated that artificial lighting can influence(More)
Artificial light at night has a wide range of biological effects on both plants and animals. Here, we review mechanisms by which artificial light at night may restructure ecological communities by modifying the interactions between species. Such mechanisms may be top-down (predator, parasite or grazer controlled), bottom-up (resource-controlled) or involve(More)
This paper describes: (a)methods for the high and low temperature ashing of biological tissue samples about 10(-4)-10(-5) g in weight; (b)a method of spraying the solubilized ash on to specimen grids which produces droplets of a size convenient for their quantitative analysis in a transmission electron analytical microscope (T.E.A.M.), but without the need(More)
Artificial light is globally one of the most widely distributed forms of anthropogenic pollution. However, while both the nature and ecological effects of direct artificial lighting are increasingly well documented, those of artificial sky glow have received little attention.We investigated how city lights alter natural regimes of lunar sky brightness using(More)
Technological developments in municipal lighting are altering the spectral characteristics of artificially lit habitats. Little is yet known of the biological consequences of such changes, although a variety of animal behaviours are dependent on detecting the spectral signature of light reflected from objects. Using previously published wavelengths of peak(More)