Following Poachers That Illegally Capture the Nation's Protected Singing Birds.

The activist's gaze sweeps over vast expanses of open meadows, searching for suspicious activity in the inky blackness.

He speaks in a hushed tone as the team seeks a spot to hide in the fields. Behind us, the huge urban center of Beijing remains asleep. During the vigil, we hear only the sound of breathing.

And then, as the sky starts to lighten ahead of sunrise, the sound of footsteps emerges. Illegal trappers are present.

Snared

Across the heavens, billions of birds, many so small that they could rest in the cup of a hand, are traveling to the south for winter.

They have taken advantage of the long summer days in northern regions, feasting on insects and fruit. As the year winds down and cold breezes bring the initial freeze of winter, they journey to warmer places to breed and eat.

There are over 1500 bird species, which is about 13% of the world's total – over eight hundred of those are migratory birds. Several of the major flyways they follow converge in China.

The patch of grassland being monitored, on the outskirts of the Chinese capital, is an refuge for small birds – any further and the urban landscape offer little opportunity to rest among forests of concrete.

It is also an oasis for the poachers and their "barely visible nets", so fine you can hardly spot them.

The one we nearly walked into was stretched across half the length of the field and held up with wooden sticks. In the middle, a tiny bird was desperately trying to free his legs, but the more it moved, the more its claws became tangled.

This was a protected songbird, a protected bird in China, and an important "bio-indicator" – meaning if its population is healthy, so is its habitat.

Tracking the Trappers

The conservationist, in his thirties, performs this duty for free using his personal funds. He has given up on many nights of sleep to rescue birds, and he has spent the last 10 years convincing the police in Beijing to take this crime seriously.

"In the early days, authorities were indifferent," he states.

So he recruited volunteers who did care and established a group called the Bird Protection Unit. He held community gatherings and invited the heads of the local police and forestry bureau. These consistent and determined acts of persuasion have shown results. The police discovered that apprehending illegal hunters also led to tracking down other kinds of criminal activity.

"We found our objectives became partially aligned," Silva says, while pointing out that implementation remains inconsistent.

Silva's love of birds began during childhood. He was raised in the 1990s in a distinct era for the city.

He recalls wandering in the fields on the city's edges where he discovered birds, frogs and snakes. "However, beginning in the 2000s, the transformation was dramatic."

Rapid economic growth brought a huge influx of rural workers to cities. This expansion meant grasslands were considered empty places to build, not sanctuaries to preserve.

The change stunned Silva. The grasslands began to shrink, as did the ecosystems they sustained.

"I made the choice back then to dedicate myself to preservation and I followed this course," he says.

It has not been an easy life. One of Beijing's biggest bird dealers discovered he was under scrutiny by Silva and retaliated.

"He gathered several of his associates who confronted me and beat me up," Silva remembers. He says he reported to the police but those responsible were not brought to justice.

He has also lost his army of volunteers over the years. This work requires covert operations and lost sleep. Silva says not many are prepared for the challenging and occasionally risky job.

"I do this full-time," he says. "I made it a project because if you want to solve this big problem, you must devote yourself wholeheartedly. You can't do it part-time."

He says fundraising covers some of the costs – over 100,000 yuan a year – but donations have dipped because of the economic situation.

So he has found new ways to hunt the hunters.

He examines aerial photos to find the trails worn away by the poachers. He maps those against the birds' flight paths and looks for areas where they may rest. The satellite images can even show lines of net traps which can catch hundreds of small birds during darkness.

"Siberian rubythroats and bluethroats sell for a premium," Silva says. "In urban centers like Beijing and Tianjin, those who want to own songbirds are now quite wealthy."

While there are environmental regulations in place, Silva argues the fines to punish the crime do not outweigh the financial benefits of catching and selling songbirds.

Owning a pet bird was – and for some generations in China, still is – a status symbol. This dates back to the Qing dynasty. Wealthy individuals would build ornate bamboo cages to display their birds.

This custom that continues mainly among retired men in their 60s or 70s. Silva says older Chinese people don't realise they are breaking the law, or understand that so many more birds were killed in a trap for them to purchase a pet.

"This generation didn't even have enough to eat growing up. Now with some disposable income, they have adopted the practice of keeping birds in cages," he says. "The nation progressed so fast, there was little opportunity to educate people about the environment. Once adults' values are set, they're extremely difficult to change."

Apprehended

Along a riverside path in Beijing, a trader has several small cages with tiny twittering birds.

Another man stands outside a local market holding a bird cage shrouded in a black veil. He tells passers-by quietly that his songbird is rare, worth about 1900 yuan.

This offers a view of an traditional side of the city where informal vendors have established a niche trade.

The path alongside the water extends over several miles and on a sunny weekday morning, there were people looking at everything from old trinkets to dentures.

Information suggested that protected birds could be bought in a small park. It was easy to find.

Loud music played from a speaker in a shaded area where a troop of elderly ladies were choreographing a fan dance. Close by several men, all over 50, had congregated with bird cages – some had multiple in their hands. Most were concealed by black fabric.

But on this occasion there would be no sales because the police had arrived. They were questioning the bird owners and recording details. Defiant, one man said he was {taking his caged bird for a walk|simply exercising his