Red Light at Night: A Potentially Fatal Attraction to Migratory Bats
Night time light pollution is rapidly increasing across the world. Nocturnal animals are likely to be especially affected but how they respond to artificial light is still largely unknown.
Each year, light pollution increases by around six per cent worldwide. In particular, energy efficient and cheap LEDs are more and more used. Light is an important cue for orientation used by many animals, and also influences their diurnal rhythms and behaviour. It is well established that bats are sensitive to light while hunting at night. While some species are attracted to artificial light sources because of the insects nearby, most bat species generally avoid artificial light.
During late summer, thousands of bats migrate along the coastline of the Baltic Sea in Latvia, through Pape Nature Reserve. Nights are starlit and largely devoid of light pollution as there are only a few human settlements in the area. Here, the scientists installed an eight metre high pole near the shoreline. A plastic board fixed to the pole was lit-up in 10-minute intervals alternating with darkness. The LED lights illuminating the board switched between red or white LED light. By using ultrasonic microphones the scientists recorded the echolocation calls of bats coming close in order to identify both the species and the number of bats passing by the unlit or lit experimental site.
Soprano pipistrelles (Pipistrellus pygmaeus) and, to a lesser degree, Nathusius’ pipistrelles (Pipistrellus nathusii) were recorded more frequently at the experimental site during the red light phase than during darkness. However, bats did not use the artificial light to hunt insects, since the number of hunting echolocation calls remained approximately constant during the light-on periods.
“Bats are at a higher collision risk at wind power stations during their autumn migration. Our study indicates that the use of red light signals could have fatal consequences for them as this appears to attract them to operating wind turbines,” explains Oliver Lindecke, co-author of the study. Technological solutions already available could help: “Existing light signals could easily be replaced by bat friendly alternatives, or context-dependent illumination could be deployed which is only activated if planes or helicopters are approaching a wind power plant.”
Exactly why bats are attracted to red light sources is unclear. “Bats have excellent eyesight and can even detect wavelengths invisible to us. Some red light sources might potentially blind and disorient them. Whether they then respond by flying towards the source of light with the highest intensity requires further research. It is also absolutely crucial to understand the long-term impact of increasing light pollution on populations of nocturnal animals,” explains Christian Voigt.
Contacts and sources:
Forschungsverbund Berlin
Source: http://www.ineffableisland.com/2018/08/red-light-at-night-potentially-fatal.html
Anyone can join.
Anyone can contribute.
Anyone can become informed about their world.
"United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
Please Help Support BeforeitsNews by trying our Natural Health Products below!
Order by Phone at 888-809-8385 or online at https://mitocopper.com M - F 9am to 5pm EST
Order by Phone at 866-388-7003 or online at https://www.herbanomic.com M - F 9am to 5pm EST
Order by Phone at 866-388-7003 or online at https://www.herbanomics.com M - F 9am to 5pm EST
Humic & Fulvic Trace Minerals Complex - Nature's most important supplement! Vivid Dreams again!
HNEX HydroNano EXtracellular Water - Improve immune system health and reduce inflammation.
Ultimate Clinical Potency Curcumin - Natural pain relief, reduce inflammation and so much more.
MitoCopper - Bioavailable Copper destroys pathogens and gives you more energy. (See Blood Video)
Oxy Powder - Natural Colon Cleanser! Cleans out toxic buildup with oxygen!
Nascent Iodine - Promotes detoxification, mental focus and thyroid health.
Smart Meter Cover - Reduces Smart Meter radiation by 96%! (See Video).