Lighting and wildlife

The potential effects of lighting on wildlife and the environment is often overlooked. Evidence suggests all forms of artificial lighting (including LEDs and halogen) can impact on wildlife. Light pollution from inappropriately positioned security lighting is often the worst culprit.

Impact on wildlife

Artificial light in gardens disrupt natural behaviour for some wildlife so it's important to retain some dark areas

Nocturnal insects, including many moths navigate in part by natural light sources, such as the moon, and can become disorientated by artificial light, wasting energy and reducing their efficiency as nocturnal pollinators

Many bat species avoid lit areas altogether and although some bats are more tolerant and take advantage of the accumulation of insects at artificial lights to hunt, it can then open these species up to the risk of predation

Security lights may temporarily blind some animals and may even attract them, as appears to be the case with frogs

Garden birds are disturbed from sleep by sudden lighting and can begin singing before dawn. Robins especially seem sensitive to light and will extend their feeding period into the night where artifical light is present. Owls may find hunting more difficult in lit, urban areas and birds that prefer to start migration flights at night can become disorientated

Disruption of animals’ breeding cycle is more serious. Light pollution is thought partly to blame for the decline of glow worms; these emit low, greenish light to attract mates

Dim lights, such as white solar powered lights, are less likely to affect wildlife. But avoid coloured solar lights as these seem to confuse and attract glow worms

Minimising impact

Ask yourself whether you really need lighting

Lessen the effects of lighting by positioning lights as low as possible and aiming lights responsibly

Turn garden lights off when not in use or use motion sensors or timers for essential or security lighting

Hoods can also direct the light downwards to reduce light pollution of the night sky

Choose low-intensity lighting and warmer hues (warm white, yellow or amber): solar lighting is cheap, safe and emits a dull glow suitable for garden use

Encourage local councils to adopt switch-off schemes for street lighting: even part-night lighting instead of full-night lighting has been found to reduce negative impact on the behaviour of moths

Measures to reduce negative impacts of lighting on wildlife are also likely to be beneficial in reducing adverse impacts on people - see Chapter 4 page 4 'Light pollution and health' from the UK Government's Annual Report of the Chief Medical Health Officer 2017: Health Impacts of All Pollution - what do we know?