"Okay, let's hope it works," chuckled the Venerable Benkong Shi after performing one final bow to the boxes. Then it was time to set the birds free. Like Noah releasing the dove of peace, another monk gently removed the birds one by one while his colleagues snapped photos on their smartphones. The northern flicker darted into the brush. "Bye-bye!" the Abbess Jingyi Shi, 51, called after the birds. "Be careful!"

From a nearby bench, a grizzled New Yorker--coozy-clad Pabst in hand--surveyed the scene. "I come here to get away from people," he grumbled. "And here I am surrounded by some sort of religious ceremony."

The group didn't seem to hear.

This unusual ritual--which drew puzzled looks from several passersby--all began with a turtle in a plastic box. In 2007 a nun at the Grace Gratitude Buddhist Temple in Manhattan's Chinatown opened the temple's bronze door to find a tiny red-eared slider at her feet. The turtle was meant not for her but for Benkong, an elder monk there. This was no abandoned baby in need of care, they suspected--it had likely been left in protest.

A month earlier Benkong had inadvertently offended New York City's entire Chinese Buddhist community. Conservationists in the city had noticed an increase of nonnative turtles in Central Park's Turtle Pond and along the banks of the East River. The problem traced back to the thousand-plus-year-old practice of fangsheng, "release life," in which Buddhists free caged animals into the environment as a way of generating positive karma through acts of kindness. "Children with their grandmas were kissing turtles--never mind the salmonella--and releasing them into ponds in New York, where they'll probably freeze to death," Benkong says.

In fact, releasing animals into the wild without a permit in New York is outright illegal. A journalist covering the issue interviewed Benkong and quoted him as dubbing the practice, a bit indelicately, as fangsi: "release of death." Benkong also blamed the misguided releases on "ignorance" on the part of his fellow Buddhists, a statement that did not go over well with readers. "That's when the shit hit the fan," he says. "Ignorance is one of our cardinal sins."

Now, after weeks of threats and racist comments ("Being a white man dressed like this didn't help"), his offhand remark had again come crawling back to haunt him in the form of the little slider. "Now I have this turtle, what can I do?" he remembers thinking. "I can't sell it, release it, or kill it."

Instead, he and a nun raised it, naming it Pyewacket after the cat in the Jimmy Stewart- Kim Novak comedy Bell, Book, and Candle. He also resolved to find a solution to the problem that had created the whole mess in the first place.

Benkong first became aware of "mercy releases" in 1969, as a 17-year-old (then Harold Lemke) freshly arrived in Taiwan. Disenchanted with life in the heroin-and crime-rife area around New York, he'd quit high school in Jersey City and announce to his parents that he was transferring to the Taipei American School. He had been interested in Buddhism since his father had given him a book on the religion five years earlier. But now, arriving at last at a Taiwanese Buddhist temple, he was perplexed to find the place crawling with chickens. "I thought to myself, 'This is strange--we're vegetarians,' " he remembers. As it turned out, the monks used any spare change left over from trips to the local market to save chickens from the chopping block.

Today many practitioners have largely forgotten the practice's original purpose--protecting and rescuing animals--and instead view the ceremony as a means of slaking more worldly desires: maybe increasing longevity, curing a relative's thyroid cancer, or getting a child into a good school.

In China, especially, non-Buddhists looking for a karmic boost picked up on the idea, and a market quickly popped up to meet demand. No exact figures exist for the number of animals affected, but conservationists working in Asia estimate the numbers climb into the millions. By the time they are released from their cages, many of the creatures, which range from sparrows to crabs, are sick or already dead, rendering the whole point moot. Some of those that do survive establish themselves as invasive species, as has happened already with American bullfrogs and red-eared sliders turned loose in China and snakehead fish in the United States.

"Unfortunately, so many Chinese people in general don't have an awareness of animal welfare or protection," says Fengqing Yu, a conservationist with the Chinese organization Wildlife Ark. "They're just following their old habits and religious beliefs." Benkong agrees that there's nothing malicious in all this, a little commercial opportunism aside. He thinks that most people "are merrily going around releasing these animals because deep down they believe they're helping them."

In North America the practice is more hush-hush. Few scientists have looked into it, but those in the know express concern. "Mercy releases are a growing problem," says Chris Harley, an ecologist at the University of British Columbia. Alien species, including snakehead fish and sea snails (which carry a potentially dangerous parasite), have turned up in waters around Vancouver, though the good Samaritans--Buddhist or otherwise--behind those invasions remain unidentified. "It is entirely possible that Buddhist releases were responsible," he says, but these practices "are not well documented and are completely unregulated."

Bent on finding a solution that is regulated, Benkong realized that certified wildlife rehabilitators often let animals go--unblessed. If Buddhists could join in, they could receive fangsheng credit without throwing a wrench into local ecosystems. He placed an ad in the New York Turtle and Tortoise Society's newsletter and found two local turtle rehabbers, Patricia Johnson and Lorri Cramer, who were willing to work with him on the idea, which he called "compassionate release."

"When you're dealing with cultural traditions, sometimes you can't say, 'You can't do that,' or 'This is wrong,' " Johnson says. "That's what I love about the compassionate release: It's taking something that serves a real spiritual service for a lot of people, and redirecting it just a little."

Benkong also took part in forum discussions in Taiwan, where Fengqing Yu and her group undertake educational campaigns in the Buddhist community and push for legislation to regulate releases. Mostly, though, he focuses on efforts closer to home. Since 2008 he has organized about a dozen turtle ceremonies. Now he's moved on to birds.

Back in Central Park, the wood thrush and yellow-bellied sapsucker had flown away and the autumn sun was setting. Before heading back to Chinatown, Abbess Jingyi Shi bid xie-xie to Rita McMahon, the Wild Bird Fund's director, and presented her with an offering: a check for $2,000. "This is a big, big help," McMahon said. "It keeps the doors open."

As Benkong likes to point out, temples have ample funds to give--something that rehabilitators tend to lack. "There are 145 Buddhist temples in New York City," says Benkong, adding that he is in the process of contacting all of them. But his ambitions reach beyond the five boroughs. He and Johnson are coauthoring short books about compas- sionate release--one written in English and Chinese and the other in the language of science--which they plan to send to temples, conserva- tionists, and rehabilitators around the country.

"My ultimate goal is for every Buddhist temple in the United States to have a rehabber or conservation group that they support and use to educate their community," says Benkong. "They just need to come knock on our door."