As the nights draw in, we increasingly rely on artificial lighting, but there is growing evidence to show that light pollution has a harmful impact on wildlife – from disorientating moths and glow worms, to reducing the hunting effectiveness of owls and bats.

The 24-hour diurnal cycle has been a constant over millennia and life has evolved to follow this cycle of night and day. Plants have photoreceptors that they use to determine day length. Deciduous trees exposed to light at night come into leaf earlier and hold their leaves for longer. Artificial lights that run all night, like streetlights, cause plants to photosynthesise for longer and make leaves grow tougher and less palatable for insects.

Unfortunately, artificial light is contributing to the alarming decline of insect populations along with habitat loss, pesticides and climate change. Nocturnal insects, like moths, navigate using natural light sources, such as the moon, and are disorientated by artificial light, wasting energy, increasing their risk of predation and reducing their efficiency as nocturnal pollinators.

Insects are fatally drawn to light sources and become ‘trapped’. Studies suggest that around one-third of these insects don’t survive to the morning, due to predation, exhaustion or hunger. Bramble is an important food source for night-flying moths, so leave a patch of bramble to flower in a dark corner of the garden.

Glow worms, once a common sight in rural areas, can still be glimpsed in rough grassland, unlit verges and hedgerows on warm summer nights. These bioluminescent creatures are a type of beetle. The female emits a soft green glow after dark to attract the male. Lighter night skies make the creatures less visible to each other, reducing their breeding success.

Bats have adapted to a life in darkness to avoid predation. They travel long distances through the night from their roosts to feeding sites. Many bat species will avoid flying or feeding in lit-up areas, making it harder for them to find food. Floodlighting on historic buildings impacts bats as they roost in the crevices of old buildings.

Rural areas offer the last dark nightscapes and a refuge for nocturnal species. We can help wildlife by reducing the amount of artificial light in our gardens and around our buildings. Drawing curtains and blinds prevents light from spilling out of our homes, and limit garden lights to evenings when out in the garden.

For outdoor security lights, motion-sensor rather than timer lights are more effective. Choose lights with shields or position them so that their beams point downwards. To illuminate steps or an uneven path, place lighting as close to the ground as possible. Keep outdoor Christmas lights modest and timed to switch off early in the evening.

At the community level, councils can play a significant role in reducing light pollution by switching off or dimming streetlights by a certain time and giving careful consideration to the floodlighting of sports pitches and buildings. Starry skies are a magical sight to be protected for wildlife and our own enjoyment.