Light pollution harms bats and their prey

Artificial light disrupts navigation, roosting and feeding

  • Artificial lights attract flying insects – bats hunting these insects are exposed to predators.
  • Other bats avoid lights, so are unable to cross or feed at sites with artificial lighting.
  • Bats emerge around sunset to feed – artificial light delays feeding because resting bats do not notice night fall.
  • Artificial light exposes bats to predators when leaving rest sites (roosts), and causes them to abandon roosts altogether.
  • Lighting near bats’ travel routes can increase their flight time and energy use by cutting them off from food and water sources.
Bat
Lights and bugs

Which lights are most harmful?

  • Artificial lighting at roosts, feeding sites and travel routes excludes bats from suitable habitat.
  • High-intensity, elevated and upward-facing lights will have the strongest effect.
  • White lighting is harmful to a wide range of bat species.
  • Red lights can be seen by some bats, but are the least likely to affect most species.
  • Amber and red lights are also less likely to attract insects away from their natural habitats.

Preserving naturally dark roosting and feeding sites, connected by dark corridors, is vital for all bats.

Australia is home to over 90 bat species. Of these, 12 are listed as threatened under the Environment Protection and Biodiversity Conservation Act 1999. Carnivorous (insect, fish and other animal eating) bats are highly adapted to finding prey in the dark, while avoiding predators. These species are particularly vulnerable to the effects of light pollution. Fruit and nectar eating bats may be less affected, but some avoid artificial light when roosting and travelling.

How you can help

  • Don’t light up bat roosts, feeding sites, water sources, and connecting corridors (travel routes).
  • Avoid lighting near waterways, as these are a key source of insect prey.
  • If lights are needed, use low-intensity red or amber lighting, installed at least 50m from bat habitats.
  • Point lights downwards and use shielding to keep light out of roosts, trees and the sky.
  • Rows of trees or hedges will help screen out lighting and create linear landscape features that can be used by travelling bats.