LED lights may impact bat populations, research shows
Energy-saving lights seems to attract some bat species, repel others
New research from Germany suggests LED lights aren't just good for the wallet — they're also good for certain bats in urban areas.
A paper published by Berlin's Leibniz Institute for Zoo and Wildlife Research suggests that as cities transition from conventional street lighting to more energy-efficient LEDs, the behaviour of hungry bats is also changing.
How some bats are being 'led' astray
Speaking on CBC's Mainstreet, Halifax zoologist Andrew Hebda said the relationship between lights and certain species of bats, known as "opportunistic bats," comes down to food.
"Lights attracts different species of insects, and the bats realize this, and they will come and forage in and around the lights," said Hebda.
Bat species such as the eastern pipistrelle, which accounts for less than five per cent of the total bats in Nova Scotia, can tolerate ultraviolet light found in conventional street lamps when they are hunting for insects such as moths and mosquitoes.
But when it comes to LEDs, these "opportunistic bats" are not so tolerant. The latest research demonstrates that sightings of species like pipistrelles decreased by 45 per cent around these types of street lamps.
Hebda adds that several migratory bat species that visit Nova Scotia might also shy away from LED lighting.
Bright future for other bat species
However, there are several species in the province that may benefit if we were to transition from conventional mercury-vapour street lamps towards LEDs.
The little brown bat, or Myotis lucifigus, derives the second part of its Latin name from its light-fleeing behaviour.
Traditionally these bats avoid conventional street lighting, but in the Leibniz Institute's findings, a transition to LED lighting saw a sightings of myotis bats increase by 400 to 500 per cent.
Overall takeaway is positive
Despite the conflicting information that these lights decrease the sightings of certain species and increase others, Hebda says the overall takeaway is positive.
Hebda said if Nova Scotia were to transition to LEDs, "ultimately, we would have a greater biodiversity of bats within the urban area."
"If our populations are strong, then we would probably see an increase in bat presence in urban areas," he said.
The best news? Hebda said more bats means more predators of mosquitoes: "That would be a bit more pleasant when it comes to nuisance insects."