Song produced and performed by Lewis Lolya (lyrics and music adapted from Damon Albarn and Jamie Hewlett)
Lyrics
Oh, joys arise
The spring has come again to hold you
Washing out the doldrums of our lives
The polyphonic atmosphere, it’s all around you
It’s all around you, out here
If the whole world is listening now
Fly through space and through time with me
The concrete and the payphone wire, is here to hold you
Rolling cross, the forests where you sleep
The towers and the photographic lights confuse you
Reflections all around you in your mind
And now your world comes crashing down
Fall though space and through time with me
The forests that we leave behind on warm air rising
Blows all our feathers far away
physiology, sailing on
A little wing, working the machine
Will it spin, will it soar
My little wing, working the machine
Soar like a wave, your rise and fall
And moving in, to where you’ll be, above it all
Lyrics Meaning
Every spring, North America transforms into a vivid landscape full of life. The warm air and sunlight awakens dormant trees, flowers and insects that fuel our ecosystem engines. Wildlife take advantage of these productive seasons to reproduce and to stock up on food resources, while they last. Even wildlife from other continents choose to migrate to North America every spring. The most ancient and spectacular of these mass movements is spring bird migration.
Thousands of birds migrate at night, and they can even be heard flying overhead. Short calls and vocalizations are used to communicate with each other and orient themselves. Before large scale human development of North America, birds flew over a dark and natural landscape, flying by only the light of the moon and the stars. Now, if a bird gazes across the land, dark forests and prairies are broken up by vast city-scapes and beams of light rising from the ground below. Tall buildings, often towering far above the height that migrating songbirds fly, create a vertical obstacle course for flying birds.
As one can guess, millions of birds die every year during migration just by chance that they may strike these human structures. Collisions with windows and buildings is estimated to be the number one cause of bird deaths globally; second being feral cat depredation (Klem, 2007). However, it is not only the density of buildings that is a problem. For low flying aircraft to avoid a similar fate, most tall structures are required to be illuminated by a series of nocturnal operated lights. Birds become confused by these lights as they conflict with natural visual migration tools in the night sky, like stars, the moon, and the horizon glow. Many birds will circle around bright lights in a disoriented state until they become too exhausted to continue migrating (Gauthreaux and Belser, 2006). Often, the final resting place for these individuals is in the grasp of a predator. More often then not, an attraction to these lights leads to fatal building and window strikes.
The attraction of birds to lights can be exemplified using high intensity lights to trap or attract birds. In India, villagers historically would use spotlights and lanterns to attract and kill hundreds of birds for food. Light traps even bolster ecotourism opportunities for seeing birds at eco-lodges in Africa (Gauthreaux and Belser, 2006). It is thought that when birds see bright lights, their visual reference for the horizon of the landscape is lost, and the birds become spatially disoriented (Herbert, 1970). Additionally, some researchers have predicted that the visual pigments in the bird’s retina become “bleached” when exposed to bright lights; rendering the bird incapable of dark adapted vision for a long duration of time afterwards (Verheijen, 1985). Birds use 5 different types of visual pigments and seven photo receptor types (varieties of rods and cones) (Hart, 2001). With this variety, birds can see a much broader spectral range of light at a finer resolution than humans.
Sources of light that have posed significant problems for migrating birds have been lighthouses, floodlights, city lights, horizon glows, fires, flares, and communication towers (Gauthreaux and Belser, 2006). In a study by Gauthreaux and Belser (1999), effects of different communication tower arrays and lighting styles on nocturnal bird migration behavior were assessed. Types of lighting sampled were red tower lights and white strobe lights. Towers with steady red lights yielded significantly more nonlinear bird flights near the towers than towers with white strobe lights and control sites (also see Wiltschko et al., 1993). Additionally, more birds flew closer and spent more time hovering around the red lighted towers, which suggests that certain light wavelengths might be more effective than others at inducing bird disorientation when migrating (red light: Wiltschko et al., 1993; green light: Poot et al., 2008).
Figure 1: Flight paths of migrants near the WVBRZ television tower in Baton Rouge, Louisiana.
Figure 2. Results of Beacham (1982) and Gauthreaux (1982) experiments on the direction of migration attraction of caged songbirds with varying directions on unnatural light exposure. White arrows represent experimentally introduced light and lines represent frequency and direction of migration flight attempts of the caged songbirds of two different species.
Solutions
A variety of educational campaigns are underway to inform building and city managers of the benefits of turning off excess lighting during times of peak bird migration. One such program, the Fatal Light Awareness Program (http://flap.org/), outlines protocols for reducing the effects of building lights on bird migration. If enacted, these efforts will prevent millions of unnecessary deaths of birds every season. In general, city lights should always be pointed downward. Spotlights that point in upwards directions should always be avoided, such as architectural lighting. These types of lights should be turned off on nights of high migration activity, low cloud cover ceilings, and low visibility weather events. If you know of any buildings that utilize these types of disruptive architectural lighting, take the time to inform building managers of the benefits of shutting off lights during bird migration events. A flick of a switch can save hundreds of lives.
Figure 3: Program outline for FLAP (www.flap.org)
Literature Cited
Beacham, J. L. (1982) Pbototaxis and age dependent migratory orientation in tbe indigo bunting, Passerina cyanea. M.S. thesis, Clemson University, Clemson, South Carolina
Gauthreaux Jr SA, Belser CG. (2006) Effects of artificial night lighting on migrating birds. Ecological consequences of artificial night lighting (C. Rich and T. Longcore, Editors). Island Press, Washington, DC, USA. 67-93.
Gauthreaux, S. A. Jr. (1982) Age-dependent orientation in migratory birds. Pages 68-74 in F. Papi and H. G. Wallraff (eds.), Avian navig. Springer-Verlag, Berlin
Gauthreaux, S. A. Jr., and C. G. Belser. (1999) The behavioral responses of migrating birds to different lighting systems on tall towers [abstract]. In W R. Evans and A. M. Manville II (eels.), Avian mortality at communication towers. Transcripts of proceedings of the Workshop on Avian Mortality at Communication Towers, August 11, Cornell University, Ithaca, New York. Online: http://migratorybirds.fws.govlissues/towers/agenda.htrnl.
Hart, N. S. (2001) The visual ecology of avian photoreceptors. Prog in Retinal and Eye Research 20:675-703.
Herbert, A. D. (1970) Spatial disorientation in birds. Wilson Bulletin 82:400-419.
Klem Jr D. (2007) Ecological consequences of artificial night lighting. The Wils Journ of Orni 119(3):519-21.
Nehring JD. (1998) Assessment of avian population change using migration casualty data from a television tower in Nashville, Tennessee. 1998.
Poot H, Ens B, de Vries H, Donners M, Wernand M, Marquenie J. (2008) Green light for nocturnally migrating birds. Eco and Socie 13(2).
Verheijen, F. J. (1985) Photopollution: artificial light optic spatial control systems fail to cope with. Incidents, causations1 remedies. Exper Bio 44:1-18.
Wiltschko W, Munro U, Ford H, Wiltschko R. (1993) Red light disrupts magnetic orientation of migratory birds. Nature 364(6437):525-7.