Each morning for more than a month, well before dawn, a pair of Mecklenburg Audubon Society volunteers has patrolled the sidewalks of uptown Charlotte. It is somber duty for bird lovers, because they’re collecting corpses.
Fall is when migratory birds wing their way south down one of the four broad flyways that span North America. Many fly at night, the moon and stars guiding them to ancient wintering grounds.
But eons of evolution never prepared birds for cities. The bright lights of tall buildings attract the migrants, which often crash into them or circle, confused, until they drop exhausted to the ground.
Millions of birds a year die that way, researchers calculate. That’s why Jill Palmer and fellow Audubon volunteer Sarah Linn walked Tryon Street, peering into niches and under shrubs, in the early-morning dark Tuesday.
Audubon is compiling data on bird deaths in uptown Charlotte. The group hopes the numbers will persuade building owners to turn off exterior lights late at night for a few weeks a year during the fall and spring migrations.
They’ve found 48 dead birds since mid-August: A wood thrush Tuesday; five Monday, including a ruby-throated hummingbird; 13 last Thursday.
Ten days of patrols in late April and May found 23 dead birds, including warblers and thrushes that had flown 2,500 miles from Central and South America and were within a day of their destination.
“It’s the first bird that gets you,” said Palmer, an accountant who coordinates the campaign, called Lights Out Charlotte.
“Picking it up and holding it in your hand and realizing how small they really are, practically weightless. He may have flown from Canada, and just needed for us to do one small thing.”
The 20 Audubon volunteers who take turns patrolling uptown start early, before cleanup crews and feral cats remove the carcasses. An unknown number of birds fall dead onto ledges or rooftops without reaching the ground.
“We don’t know the real numbers, but we know that anything we collect is a very small percentage of what is actually killed,” said Don Seriff, a natural resources coordinator for the Mecklenburg parks division who helps identify the birds. “We’re already getting some pretty surprising numbers, to my mind.”
Researchers estimate that 100 million to 1 billion birds die each year in North America after slamming into buildings. Most often, they hit windows. Birds see sky, water or trees reflected in the glass and fly toward it.
The Fatal Light Awareness Program, a Toronto group that dates to 1993, estimates that 1 to 10 birds die per city building each year. Most fatalities occur at the tallest buildings.
When lights lure night-flying migrants into cities, said FLAP executive director Michael Mesure, the birds find themselves in unfamiliar surroundings come daylight. That leads to window collisions.
About 30 North American cities have followed FLAP’s lead.
In Chicago, most tall-building owners have agreed to shut off their decorative lights each spring and fall. Field Museum researchers have estimated that the program saves more than 10,000 migratory birds a year. New York, Boston, Washington, D.C., Baltimore, Minneapolis and San Francisco have similar programs.
Lights Out Winston-Salem, a year-old project of Forsyth Audubon, suggests the approach works.
Of the five tall buildings that now shut off lights, only one had burned its lights all night, said coordinator Kim Brand. That building, Liberty Plaza, had accounted for 12 percent of the dead, stunned or injured birds found since last October. Since dousing its lights beginning May 15, she said, the building has accounted for only 3 percent of the victims.
Mecklenburg Audubon has not yet approached Charlotte’s building owners. But the city may have a ready-made incentive: The Smart Energy Now initiative that aims to cut energy use in uptown buildings by 20 percent over five years.
“We tend to get relatively consistent, positive response on the night (light) issue because our goal coincides with theirs, to save energy,” said Mesure, the FLAP director. The twin goals diverge, he added, when buildings install low-wattage lights to save energy rather than cutting them off at night.
The initiative has let Audubon post lights-out information on its blog.
“We’re going to support it as a side benefit but it would not be part of our overall strategy,” said Paige Layne, a spokeswoman for Duke Energy, a major funder of Smart Energy Now. “Certainly we consider all requests when they come to us, but we don’t make the call on those exterior lights. … I guess it would be a collective decision.”
The Duke Energy Center, owned by Wells Fargo, is among uptown’s most-illuminated buildings with colored neon running up its sides and top. Wells spokeswoman Alexandra Ball said the bank would have to evaluate whether to change how the lights are used.
“Certainly we would at least have that conversation with them,” she said. “We do have a very strong environmental commitment.”
Bank of America, which own the city’s tallest tower, would need more information before deciding whether to take part, a spokeswoman said.