Birds and the colour of light

Discussion with a Swedish colleague prompted me to find out what the biologist Hanneke Poot found out about colours of light and migrating birds.
Information was found at the site:
http://www.serpentproject.com/assets/pdf/SeaQuest-Reprint-April05.pdf



It has been known for some time that migratory birds are much hindered by the lightning of oil platforms. The birds loose their ability of orientation, fly towards the light, fly circles around the platform or rest on it until dawn. This takes the energy they need for their migration trip.
In the North Sea, 12 years of research on migratory birds has prompted Shell to change the color of the lighting on its platforms from white to green. Though a relatively rare occurrence, birds on occasion were reportedly flying into gas flares. Shell scientists recommended that a bird watcher be hired if a platform needed to flare during the migration season. Despite these precautions, it was noted that even when no flaring took place, songbirds in particular were attracted to the platforms at night, often milling around them for hours.
After examining several options, Shell hired biology student Hanneke Poot to conduct an experiment to determine if birds respond differently to different colors of light. She determined that, while white light attracted the most birds, blue and green light attracted the fewest. Red light, meanwhile, attracted fewer birds than white but had a negative effect on their sense of direction. Blue light hardly disturbs the migration, but with blue light humans on the platforms can not work properly. Green light is the best option: 80% of the birds fly on undisturbed. Dimming the lights can further increase this percentage.
What are the consequences for the colours of offshore wind turbine lights?
Joop Marquenie (Shell / NAM), member of the board of We@Sea and involved in this field of research, answered: red lights are worldwide used for security reasons and if dimmed, birds are not hindered.
He sent a power presentation about this topic: "Birds like red-free"
For more information please mail to joop.marquenie@shell.com
Posted by Chris Westra - 2007-02-01 14:35:00