With a bit of effort, we can soften that landscape, and help the birds that grace us with their presence move safely through it.Home Discussions Workshop Market Broadcasts. Migration has always been fraught with danger, but today’s glass-hardened landscape presents a novel and extraordinary threat. For helpful guidance on design considerations for buildings big and small, visit the American Bird Conservancy’s Bird-Friendly Building project at /glass-collisions. In addition, if you live or work in a building with large windows, keep an eye out for window-strike victims, then apply screens, stickers, or decals to break up the reflections of any problem glass.
When you must use indoor lights after dark, opt for lamps that illuminate a small area instead of overhead lights that brighten the whole room, and keep your curtains or blinds closed. We can all help by turning off exterior lights and unused interior lights overnight, especially during peak bird migration season in spring (April 1 to May 15) and fall (September 1 to October 31). Thankfully, this is a problem with solutions. The researchers also determined that structures that kill only a small number of birds annually - like my local shopping center in Keene - account for a large proportion of total window-strike mortality. Despite the attention garnered by high-profile skyscrapers, a 2014 study in the journal “Ornithological Applications” found that high-rises were responsible for fewer than 1 percent of window-strike deaths, with 56 percent attributed to low-rise buildings and 44 percent to residences. Somewhere between 365 million and 988 million birds – from songbirds to raptors – fall victim to building collisions in the United States each year, second only to outdoor cats as the largest source of direct, human-caused mortality for U.S.
However, during migration, window strikes commonly occur in early morning, when hungry migrants drawn toward buildings by nighttime lights search for food and instead encounter glass – imperceptible to birds – that reflects the sky or nearby vegetation.
Intensive monitoring at a 40-story convention center in Chicago, for instance, has documented 40,000 window-strike fatalities since 1978 – but also showed that numbers dropped from thousands to hundreds of birds per year when the building began shutting its lights off at night in the early 2000s.īirds can hit windows of any height, at any time. NYC Audubon now coordinates volunteers to monitor the memorial when too many birds become caught in the lights, Tribute operators turn them off for a brief time to allow the migrants to disperse. Studies have shown that bird densities in lower Manhattan are up to 150 times higher when the Tribute lights are on. September is peak time for songbird migration, and when weather conditions align just so, thousands of birds can become “trapped” in these beams, circling until they drop from exhaustion or strike the sides of nearby buildings. One of the most well-studied instances of the effects of bright lights on migrating birds is the Tribute in Light, the powerful twin beams that illuminate the New York City skyline each September as a memorial to those lost in the terrorist attacks on September 11, 2001. Artificial lights can both attract and disorient migrating birds, drawing them to cities - and, for many, into collision courses with windows.
Many birds fuel up by day and migrate by night, when temperatures are cooler and aerial predators are less active.