Thousands of pigeons with tiny LED lights strapped to their legs swooped through the darkening skies in a jaw-dropping display of beauty, but savvy New Yorkers gazing up at the performance art knew enough to keep their mouths shut.As evening fell over the Brooklyn Navy Yard, once home to the nation's largest naval fleet of carrier pigeons, artist Duke Riley opened an enormous coop and released the homing pigeons of his "Fly by Night" project.

At the call of his whistle, the massive flock took off and circled for 30 minutes late Thursday over the deck of their temporary home on a decommissioned U.S. Navy ship, following a bamboo pole waved in the air by Riley.

What resembled air-borne embers swirling from a campfire were actually LED lights in the birds' leg bands, which historically were used to carry messages.

"It is a collaborative project between me and the pigeons," Riley said. "It's a performance or maybe it's just a drawing that they are doing in the sky."

The show will be repeated every weekend evening from May 7 through June 12.

Riley's flock includes a variety of specially trained pigeons, some of which are his own, while others were purchased or borrowed from pigeon fanciers. After the project ends, Riley will keep many of them as his pets.

"Fly by Night," which was presented by the non-profit organization Creative Time, comes three years after Riley's 2013 performance piece "Trading With the Enemy," in which trained pigeons carried cigars from Havana to Key West, Florida, to protest the U.S. embargo of Cuba and challenge American spying capabilities since the birds evade surveillance equipment.

The New York City project pays homage to pigeon keeping, whether for sport, service or companionship. Once a popular pastime on city tenement rooftops, the hobby has dropped off amid escalating real estate prices.

While dubbed by some New Yorkers as "rats with wings," pigeons have been revered for thousands of years, dating back to the ancient Christians of Cappadocia in Turkey, who valued the birds for their excrement, a rich fertilizer.

Pigeon droppings were also at the top of the minds of wary art lovers on Thursday, as 2,000 birds flew overhead, threatening to anoint onlookers with what some superstitions define as good luck.

"It was not a concern of mine at all because most animals, including humans, usually don't like to defecate while they are exercising," Riley said.

Evidence on a reporter's purse, however, proved otherwise.