Hundreds of birds migrating through New York City this week died by crashing into the city's glass towers.
The disconcerting uptick in bird casualties was particularly evident in Manhattan where an unusual number of bird carcasses littered streets around city skyscrapers.
Members of the NYC Audubon, who have been documenting the preventable avian fatalities for years, collected at least 226 dead window-struck birds around the World Trade Center alone. That just accounts for the bird carcasses that were accessible or not "too mangled to collect," explained one Audubon member via Twitter.
NYC Audubon associate director of conservation and science Kaitlyn Parkins tells NBC New York that bird strikes in Manhattan are a persistent problem, but changing seasons and stormy weather this week made conditions even more difficult for birds to navigate.
“We had a big storm and sort of weird weather and lots of birds, and that’s sort of the perfect combination that can lead to bird-window collisions,” Parkins said.
She added that “the storm might have brought the birds in lower than they would have otherwise have been, or just disoriented them. The effects of nocturnal light on birds is also quite strong, especially when it’s a cloudy night.”
Audubon volunteers like Melissa Breyer document bird deaths at high-risk spots during the spring and fall migrations.
Breyer arrived at WTC before dawn on Tuesday to find and grisly scene where the sidewalks were "literally covered with birds" in every direction.
NYC Audubon says office buildings can help reduce the number of bird strikes by simply dimming their lights at night and by treated glass to make it more visible to birds. The organization has been urging owners of the WTC and other local towers to take these steps.
A spokesperson for Silverstein Properties, developer of three WTC skyscrapers said the company is "actively encouraging" its tenants to turn off their lights at night and lower blinds wherever possible, especially in the migratory season.
Some of the birds did survive their crash. The Audubon says 77 were taken to the Wild Bird Fund's rehab facility on the Upper West Side. There they were fed and given medication to reduce swelling.
At least 30 birds recovered in short order and were released in Prospect Park in Brooklyn on Wednesday so they wouldn't face any more tall buildings during their migration.