Jurapark Aargau shows darker nights can protect wildlife

More darkness can benefit wildlife without compromising safety, according to SRF, which examined measures promoted by Jurapark Aargau, a nature park north of Aarau.

Lower levels of artificial light reduce insect deaths, but genuinely dark nights are rare in densely populated Switzerland. Many people also feel less safe with less lighting. Jurapark Aargau aims to preserve the darkness in its rural, sparsely populated region and offers advice through its “Lights off, life on” campaign.

Simple ways to reduce light pollution

Only areas that need lighting should be illuminated. Decorative garden lights do not need to stay on all night, as hedgehogs can find earthworms in the dark and trees and shrubs do not need light at night. Timers can switch lights off automatically.

Outdoor lamps should be directed so they do not shine onto roads or neighbouring properties. Carefully adjusted motion sensors can also reduce reactions to animals, while closed blinds and shutters limit the amount of light escaping outdoors.

Warmer light is less harmful to people and animals. Yellow to orange light below 2700 Kelvin has a lower impact than white light, and dimmed lighting can be sufficient in a dark environment. Many LED lamps can be dimmed.

Darkness and safety

Jurapark Aargau surveyed 340 people about how safe they felt at night. The results showed that only a small number felt uncomfortable in the dark. Although burglaries were among the respondents’ most common concerns, most supported measures to reduce light pollution, including reducing illuminated advertising and switching off or dimming public lighting.

Motion-activated lighting can make movement easier to notice than permanent lighting. At the same time, the brighter an area is, the less visible the dark area around it becomes. According to police, municipalities with reduced or switched-off night lighting do not experience more burglaries.

Wildlife that benefits

Fireflies need darkness so the glowing rear sections of females can be seen and attract males. Artificial lighting interferes with their reproduction. Some bat species also avoid light and need dark places to retreat.

Hedgehogs are active at dusk and night and avoid brightly lit areas. Light disrupts their search for food and partners. Migratory birds such as barn swallows use the moon and stars for navigation, but the brightening night sky makes them harder to see.

Artificial light attracts nocturnal insects, which can circle a lamp until they die of exhaustion. Insects play an important role in pollinating plants. Plants that grow in uninterrupted darkness are healthier, remain resistant to frost and can carry out photosynthesis. Artificial light can also disrupt people’s day-night rhythms, while less light promotes better sleep.