A young Vietnamese woman’s husband fell ill. Desperate for a cure, she later recounted, she visited the local Buddhist temple. A monk there instructed her to “release 40 birds, one for every year of your husband’s life.” So she did, purchasing and releasing 40 birds at the temple grounds. The woman soon rejoiced; her husband made a full recovery.

This is a common story in Asia, where “merit releases” of captive wild animals are performed in Buddhist rituals. But the practice raises concern amongst the conservation community for its potential to impact threatened species. Before a bird can be freed, it has to be captured—often just after having been released by someone else. The result is the denuding of wild populations and a vast recycling of mistreated animals, most of which are likely die on one of their ersatz flights to freedom. As if that were not bad enough, the dead, disease-ridden animals are then sold in food markets.

» View Photos of Merit Releases in Asia

“We were staggered by the number of birds moving through this trade,” says Martin Gilbert, a veterinarian at the Wildlife Conservation Society who recently co-authored a study in Biological Conservation on merit releases. “It’s a very good rational and understandable thing to do, to let captive animals go free,” he says. “But in certain situations, it creates a trade purely for demand for animals in cages.”

Gilbert and his colleagues monitored daily sales of merit release birds in Phnom Penh, Cambodia, over a period of 13 months. From their findings, they estimated nearly 700,000 animals pass through the local trade annually. They recorded a total of 57 bird species in the cages, including globally near-threatened Asian golden weavers and vulnerable yellow-breasted buntings. 

“This paper highlights the potentially huge impact merit releases have on a few birds that are easily caught and are already of conservation concern,” says John Pilgrim, a conservation consultant who specializes in Southeast Asia and Melanesia and who was not involved in the study.

Gilbert says he knows of only one other study, conducted in Hong Kong, which attempted to estimate merit release figures. The numbers were comparable, reporting that Hong Kong Buddhist temples released up to 580,000 birds per year.

“It’s pretty scary that this [new] paper estimates just a dozen families in two small markets sold more than 630,000 birds per year,” Pilgrim says.

Conservationists do not know how the merit release market figures into Asia’s overall wildlife trade, which also exploits wild birds for pets, food, passerine fights and song contests. Globally, trade in wild birds impacts about 400 species that are listed on the International Union for Conservation of Nature’s Red List, or one third of all threatened bird species. No one know how many birds succumb each year to the wildlife trade since much of the trafficking is illegal, but within Southeast Asia alone, it is likely “in the order of tens of millions,” says Kelly Edmunds, a researcher at the University of East Anglia in England who investigates the emerging infectious diseases amongst bird sellers in Asia and was not involved in the study.

Buddhists free captive animals in order to accumulate health and longevity merits for themselves and loved ones. The exact origins of the practice are unclear, though it was mentioned in fifth-century Chinese Buddhist texts that instructed followers to “practice the act of releasing animals due to the mind of compassion.”

Today that practice extends to birds, turtles, fish, crabs and even ants. A 1999 study in Taipei found that 29.5 percent of 1,000 randomly interviewed people had released prayer animals at some point in their life.

As hopeful as the flight of a bird from a cage may look, few of the creatures escape to a better life. After buyers free them, hunters often wait nearby to recapture the fatigued, disoriented animals. No sure mortality estimates exist for the practice, but a report (pdf) issued by the wildlife trade–monitoring organization TRAFFIC estimates that 30 to 55 percent of all birds that enter the wildlife trade do not survive. The Institute of Supervising Animal Epidemic Control of Guangzhou in China claims that 90 percent or more of the birds used in merit releases die, according to an article in the journal Contemporary Buddhism.

“There are cages rammed in with hundreds of birds of different species,” Edmunds says. “Cages are often stacked on top of one another, so feces and feather dust pass down onto the animals below,” she describes. The birds become stressed, increasing their susceptibility to disease, which is a concern for both animals and humans.

Gilbert and his colleagues tested the Cambodian birds for pathogens and found that more than 10 percent carried bird flu. Buyers come into close contact with the birds they release, and the traders sell deceased birds to roadside diners at the end of the day, which introduces the potential for disease transmission. “I was really puzzled when I first saw people kissing the birds when they released them,” says Philippe Buchy, a medical virologist at the Pasteur Institute of Cambodia in Phnom Penh who was not involved in the study. “I thought, what would happen if one of these little birds was infected with the H5N1 virus?” 

In a recent study, Buchy showed that Eurasian tree sparrows, a species commonly used in merit releases, can harbor H5N1 and transmit it to other birds. He also found viral particles on the sparrows’ feathers, meaning infected merit release birds could pass the disease on to susceptible people. “As a microbiologist, I will always say that whatever wild animal it is, humans should not go into contact with it,” Buchy says.

Still, banning merit releases outright is likely not the solution. “Who are we to say these practices are wrong?” Edmunds says. “But I think there is scope to improve the conditions under which these practices take place,” she adds. 

Gilbert imagines programs forged between researchers and Buddhist communities in which declining native species are captive-bred and then released by practitioners. The Society for Conservation Biology and Buddhist communities are already exploring initial ways of doing this. 

“I think the next logical step is work out a method that allows releases to be done in a way that is true to the original spirit of the practice,” he says.

» View Photos of Merit Releases in Asia