
News Outlets Misinterpret US Bird-Building Collision Study – But the Problem is Real

A sensational news story stating that up to a billion birds die in collisions with skyscrapers in the US every year recently made headlines and has been repeated around the world. However, the reality, though not as shocking as the headline, is nevertheless of concern.
The false impression that high-rise towers slaughter birds by the billion comes from casual reading of a study finding that between 365 and 988 million birds die in building collisions in the US.
But what the reports failed to note was that the finding points to high-rises as presenting the lowest threat to passing birdlife. Instead, low rises and residential homes produced the largest amount of avian casualties, with high-rise towers killing less than one percent of the total.
Bird Migration Poses Added Risk
However, although high rises may not be nearly as deadly to birds as the headlines declared, there’s no doubt that the mere existence of buildings poses a threat to many species. Regretfully, some of these may be rare or threatened as the US study found. Five species with vulnerable conservation status were found to represent a disproportionate amount of building collisions.
At the same time, the researchers warn that many of the data sets studied were accumulated during migratory seasons and that new data covering other times of the year would provide more accurate results.
It is true the birds are drawn to cities during their migrations. Ornithologists explain that many diurnal species prefer to carry out nocturnal migration flights, and that they will be drawn to the bright lights of cities, potentially leading flocks through airspace that’s crowded with buildings.