There are plenty of reasons to conserve electricity and energy sources. Cutting back on electricity, is of course, a big issue, not only environmentally, but economically.
Plenty has been written about conserving energy and cutting back on using eletric lights and lower wattage ones.
However, a significant reason to cut back is one most would never even consider. Artificial lights keep birds away from the cities. Keeping birds away from cities will effect the way some species of birds, potentially migrate and reproduce. It seems that unnatural lights, such as streetlights, traffic lights, neon signs and office buildings whose lights are left on have an effect on some bird species. The birds do not see the these artificial lights as welcoming nor a part their natural environments. This causes the birds to attempt to nest in unknown areas where predators may be more likely to endanger the safety of their young.
Major cities, especially ones with airports, of course, require sufficient lighting to ensure the safety of its community and population. Thankfully, many cities are adopting dark sky lighting measures to keep the light on the ground where it belongs. Smaller cities can more easily reduce unnecessary lights such as some street lights and building lights to encourage birds to nest and remain in the cities. The propagation of all the species of life contribute to the survival of all species. All efforts should be made to keep lighting up cities with unnatural light to an absolute minimum.
Birds use the natural light of the moon and stars to aid in their migratory and nesting patterns. Artificial lights, especially excessive ones, as in urban areas, certainly contribute to mass confusion among our feathered friends. Any attempts to reduce the artificially lit areas can help protect other species, our natural ecosystems, and save money while reducing energy as well.
When needed, solar lighting, light emission diode lighting (LED) can be utilized to light areas for safety reasons. Also, motion detection lighting will only turn on when activated by nearby motion, a good safety and energy saving tactic. However, lighting like these options will be invisible or barely visible to migratory bird species.