Finally, spring has arrived in New York, which means thousands of birds will be flying through the city on their spring migration south. It also means that the counts for collision-based bird deaths will begin.
NYC Audubon, a local branch of the national Audubon Society, estimates that 90,000 birds are killed in the city each year because of collisions with buildings. Most commonly killed are common yellowthroats, ovenbirds, and white-throated sparrows.
During the day, the reflective glass on New York City’s skyscrapers looks invisible to the birds, causing them to crash into the windowpanes and become injured or die. Inclement weather can cause the birds to fly lower, putting them at risk for collisions with buildings. Meanwhile, many birds also migrate nocturnally, and any light can be distracting to them. According to Debra Kriensky, conservation biologist at NYC Audubon, the many buildings in the city that leave lights on at night cause the birds to become disoriented. Migrating birds will hover around the buildings, sometimes for hours, then land to rest and find the environment inhospitable because of predators or weather.
And some buildings are worse than others. The two sites with the highest amount of bird fatalities in the city are the Metropolitan Museum and the buildings around Bryant Park. Volunteers counted 15 dead birds in spring 2014 and 50 during fall 2014 at the Metropolitan Museum. Bryant Park’s count for 2014 was significantly lower—four birds in the spring and 13 in the fall, and that’s just what a small group of volunteers finds. (Part of the ranking of the two sites is a selection bias. NYC Audubon relies on a group of about 20 volunteers to help conduct dead bird counts each year for “Project Safe Flight.” The volunteers mainly focused on the two areas because of their size. Managers of buildings around Bryant Park did not return calls and Metropolitan Museum did not supply any information).
Collision-based bird deaths can be significantly reduced by turning off lights at night. A study by the Field Museum in Chicago found that turning one building’s lights off at night decreased bird deaths by collision by 83 percent on average. To combat such deaths, NYC Audubon launched “Lights Out New York” in 2005. The initiative encourages buildings to turn out their lights at night during migration season.
But in an informal survey past midnight in March, no building around Bryant Park was completely dark, and several buildings, like the Met Life building, had most floors brightly lit.
Several other buildings around the city, including 501 Lexington Avenue, the Silverstein Properties, The Time Warner Center, and Worldwide Plaza, pledged to turn their lights out from midnight to 5 a.m. during peak migration season—from September to November.
Other cities have taken action to protect nocturnally migrating birds. Nearly 100 buildings in Chicago turn out their lights after 11 p.m. during spring and fall migrations. Minnesota’s Governor Tim Pawlenty recently signed a bill requiring state-owned buildings to go dark after midnight for the same period.
The U.S. Green Building Council, which certifies environmentally friendly buildings, launched a pilot program in 2009 to help reduce collision-based bird deaths. For a building to be certified as bird safe, it must develop a three-year plan to monitor the building’s design to prevent bird collisions and develop a plan of corrections. This includes a plan for interior lighting.
According to the U.S. Green Building Council, there are two building projects in New York City pursuing the bird collision deterrence credit, but they would not specify which ones. Nationwide, only 15 projects are in the final certification stages of the pilot credit, but none are in New York. “It’s great to know that people are taking that pilot credit seriously,” Kriensky said.
Until more buildings take up the call to action to turn their lights off, NYC Audubon will focus on counting the avian casualties. Kriensky hopes their new crowd-sourced dead bird tracker, D-Bird, will help them get a little closer to an accurate count. The web-based app allows users to report a dead bird to NYC Audubon and tag it with a geo-location stamp.
“It’s a place for anyone, not just our volunteers, to input data on where you’re finding dead and injured birds,” Kriensky said. “That definitely increased the number of birds we’re seeing just because more people are reporting to us.”
Users can also see where other birds have been reported on the app. Several woodcocks, Kriensky said, have already been reported this season through the tracker.