The peak migration season for birds has just started. From now until November flocks of birds will be on the move to warmer climes. Many birds pass through Ireland on their way to other countries. These ‘passage migrants’ include Arctic Terns and Sanderlings, small wading birds, which breed in the high arctic regions and are en route to wintering in West Africa. They use our estuaries to rest and refuel but if the winter is mild and there’s enough food they may stay. In the case of a feral pigeon they are fiercely territorial and will have to be mighty cold and hungry to give up their nesting site.
How birds navigate has been the subject of much debate but studies have indicated that birds use light to orient, rather than magnetic sensing. Birds may travel at night using the pattern of stars, and the sun during the day.
Last year 10,000 birds were lured from their migratory path towards the bright lights of the Tribute in Light at ground zero. The birds circled in confusion around the spectacular light show which casts its light into the heavens on September 11 in memory of the 9/11 terrorist attack.
Susan Elbin, NYC Audubon director of conservation, estimates that 90,000 birds die annually in New York City, because of collisions with buildings. Nationwide, the bird collision toll in the US is at least 100 million.
When it’s dark or foggy birds fly at lower altitudes, the combination of glass and artificial light confuses birds. Unable to see glass, or simply exhausted by flying around the lights,birds can be injured or killed.
A landmark study conducted by the Field Museum in Chicago showed that by turning the lights off in one building, the number of bird kills dropped by an average of 83 percent.
New York City Audubon inaugurated Lights Out NY in 2005 and a number of the city’s iconic buildings — the Chrysler Building, Rockefeller Center, 501 Lexington Avenue (formerly known as Citigroup Center), Silverstein Properties, The Warner Center and the Worldwide Plaza — will turn off their lights from midnight to dawn dusk during the peak migration season September 1st to November 1st.
In Ireland lighthouse owners noticed that migrating birds were attracted towards the beams of light during bad weather. The birds were dazzled by the beam and many died by crashing into the lantern or the tower. Birds are attracted towards the light of the burning gas being flared off platforms in the North Sea and off the coast of Cork. Many have been killed in this way, but many others find a safe perch on the brightly illuminated platforms.
In case you were wondering feral city pigeons don’t migrate. There’s enough human food left lying around for them to pick at, and with the warmth and shelter of a city why bother with a long haul flight?