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Environment and Wildlife

Dark Skies

Published: 25 June 2023

Dark skies


Why is Policy A2 of the North Devon Area of Outstanding Natural Beauty (NDAONB) “Preserve the dark skies, peace and tranquillity of the AONB”? Dark skies are also named as one of the 14 Special Qualities of the NDAONB. The International Union for Nature Conservation (IUCN) also runs a Dark Skies Advisory Group aimed at “managing artificial light to protect natural systems and to appreciate the night sky”. Exmoor became Europe’s first International Dark Sky Reserve in 2011, with its rugged moorland landscapes transforming at night into star-filled scenes. So Dark Skies are generally considered to be IMPORTANT.

The environment impact of light pollution:

Biological systems evolved under the influence of the day/night cycle and its annual variation.

Wild animals especially birds and bats are negatively affected by light pollution as it influences their ability to fit their activities and reproductive behaviour to the appropriate time of year or day. They may suffer navigation problems from night lights during migration and become seriously disoriented. Birds tend to fly toward bright lights, while bats avoid them. Their feeding habits, particularly of those that eat flying insects, can suffer from the effects of light pollution on their own behaviour as well as on the behaviour of the insects on which they feed. Insects suffer disorientation and death from attraction to lights in the night and become easy prey for insect-eating birds.

Plants have also evolved to use the seasonal cues of changing day/night lengths in order to fit their annual developmental and breeding programs to the appropriate seasons. Light pollution prevents them from using these seasonal cues so that their breeding activities may be compromised, and their development, particularly in their preparation for winter, may be affected to the point that they cannot survive seasonal changes.

Humans are likely to feel that light pollution negatively affects their inbuilt appreciation of the night environment. It may also cause sleep deprivation as well as psychological and hormonal disturbances that can have serious and sometimes lasting effects. In addition light pollution is relevant to the climate emergency. For example the energy required for street lighting in UK is calculated to waste £1 billion a year.

Overall, light pollution has no beneficial effects on the biological components of the environment: it only helps humans who wish to see in the dark. Its effects on the biological components of the environment are often seriously negative or even deadly, so lighting schemes should be developed that minimize these impacts.

Outdoor Lighting Guidelines:

Use outdoor lighting only when needed. Consider how the use of light will impact wildlife interactions and habitats. Perhaps use reflective paint or self-luminous markers for signs, curbs and steps. Outdoor lighting should not be used for aesthetic purposes. Only light areas that need light. Be aware that some surfaces reflect a lot of light into the sky

Minimize blue light emissions as these wavelengths affect wildlife night vision most detrimentally and install energy efficient bulbs and active controls such as motion detectors. Utilize fully shielded light fixtures outdoors so that the light beam does not spill beyond where it is needed, especially not into the sky. Close blinds at night to keep indoor light inside. Encourage neighbours to reduce their light pollution, particularly glare and “light trespass”.

Help to keep our parish skies dark!

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