Millions of birds of at least 250 species of fly each autumn and spring over the US. In the spring, they travel twice a year thousands of miles to the north from Central and South America, over the Great Lakes in the north of the USA to Canada, in the autumn, they fly back to the south. But many birds survive their passage about Chicago, one of the many large cities with high skyscrapers, not. Also the famous skyline of Manhattan is still such a deadly obstacle to birds. But actually, any glass or brightly lit skyscraper a culprit.
The birds are blinded by the light and fly as a result against buildings. By the light pollution they can also be difficult to the constellation of the stars follow. Many birds do a profession in the migratieseizoen. They also see transparent windows are not. Reflective windows reflect elements such as the sky, trees and the landscape. Therefore, they fly all too often at full speed against the glass.Songbirds are more sensitive
The Cornell Lab or Ornithology has published this week a study which cities ranks on the basis of the danger that they pose to migratory birds. Houston and Dallas, which are also along important migratory routes of birds, are the top three together with Chicago. New York, Los Angeles, St. Louis and Atlanta are also extremely deadly cities. The Smithsonian vogelcentrum estimates that every year between 100 million and one billion birds die. Certain bird species are more sensitive. Researchers from the university of Michigan say that songbirds, such as sparrows and warblers, are most at risk to death to fly against buildings.Measures
The extinguishing of the lights during the migratieseizoen according to the researchers, a first simple step to the massive vogelsterfte. The states of New York and Minnesota already have such a measure introduced. New York decided four years ago during the peak times in the migratieseizoen all unnecessary lights and goes out between 23 pm and sunrise. Conservationists argue in addition for more “vogelvriendelijke” buildings with patroonglas and dimmer.