On the Trail Illegal Hunters Illegally Trapping the Nation's Rare Singing Birds.

The activist's vision darts over miles of open meadows, looking for any movement in the pre-dawn darkness.

He utters a muted voice as the team seeks a place of cover in the fields. In the distance, the huge urban center of Beijing slumbers on. As we wait, the only sound is the sound of breathing.

Suddenly, as the sky starts to lighten with the approaching day, there is the crunch of footsteps. Illegal trappers are present.

Snared

Across the heavens, countless migratory birds, many so small that they could rest in the cup of a hand, are migrating south for winter.

They have benefited from the warmer months in Siberia, or Mongolia, eating insects and fruit. As the year comes to a close and chilling gusts bring the first frosts of winter, they journey to more temperate climates to breed and eat.

The nation hosts over 1500 bird species, representing roughly thirteen percent of the global population – more than 800 of those are migratory birds. Several of the major migration routes they follow converge in China.

This particular field in question, on the outskirts of the Chinese capital, is an refuge for small birds – farther in and the city skies offer scant chance to rest among towering rows of concrete.

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

The one we nearly walked into was stretched across a large section of the field and held up with bamboo poles. At its center, a small finch was struggling frantically to escape, but the more it struggled, the more its feet got ensnared.

It was a meadow pipit, a species under protection in China, and an important "indicator species" – meaning if its population is healthy, so is its ecosystem.

Pursuing the Poachers

Silva, who is in his 30s, does this work for free using his own savings. He has sacrificed many sleeping hours to rescue birds, and he has spent the last 10 years persuading the police in Beijing to take this crime seriously.

"Initially, there was little interest," he states.

So he recruited volunteers who were concerned and established a group known as the Bird Protection Unit. He held community gatherings and invited the heads of the local police and forestry bureau. These small and persistent acts of persuasion seem to have paid off. The police found that apprehending illegal hunters also helped in tracking down other kinds of criminal activity.

"We found our goals were somewhat shared," Silva says, noting that implementation remains inconsistent.

This fascination with birds started in childhood. He grew up in the 1990s in a much changed capital.

He recalls roaming through the grasslands on the city's edges where he found birds, frogs and snakes. "But starting from the 2000s, the transformation was dramatic."

China's booming economy brought millions of rural workers to cities. This rapid urbanisation meant grasslands were seen as land for construction, not conservation areas to conserve.

The transformation was alarming. The grasslands started disappearing, as did the habitats they supported.

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

This has not made for an easy life. A major Beijing's biggest bird dealers found out he was under scrutiny by Silva and retaliated.

"He assembled several of his associates who surrounded me and assaulted me," Silva remembers. He says he went to the police but those responsible were not brought to justice.

He has also lost his team of helpers over the years. This work demands patience and night vigils. Silva says few people are prepared for the challenging and occasionally risky job.

"I do this full-time," he says. "I treat it as a mission because if you want to tackle this challenge, you must give it your all. You can't do it part-time."

He says fundraising covers some of the costs – over 100,000 yuan a year – but support has waned because of the economic situation.

So he has found new ways to track the poachers.

He analyzes satellite imagery to find the trails worn away by the poachers. He charts these against the birds' flight paths and looks for areas where they may rest. The aerial views can even show netting setups which can capture hundreds of small birds at night.

"Certain prized species command a high price," Silva says. "In big cities like Beijing and Tianjin, those who want to keep birds are now often affluent."

While there are wildlife laws in place, Silva reckons the penalties to deter the activity do not exceed the financial benefits of trapping and trading songbirds.

Keeping a caged bird was – and for some generations in China, still is – a status symbol. This dates back to the imperial era. Wealthy individuals would build elaborate bamboo cages for their birds.

This custom that continues mainly among retired men in their 60s or 70s. Silva says some elderly citizens may not understand they are breaking the law, or understand that so many more birds had to die in a trap for them to purchase a caged bird.

"These individuals often lacked enough to eat growing up. Now with some disposable income, they have adopted the habit and custom of caging birds," he says. "The nation progressed so fast, there was little opportunity to educate people about ecology. Once adults' values are set, they're extremely difficult to change."

Apprehended

On a long low wall in Beijing, a vendor has several tiny enclosures with tiny twittering birds.

Another man is positioned near a local market holding a bird cage covered by a dark cloth. He informs passers-by discreetly that his songbird is rare, worth nearly 1900 yuan.

This is a glimpse of an old Beijing where informal vendors have established a niche trade.

The area by the river extends over several miles and on a sunny weekday morning, there were people looking at everything from old trinkets to false teeth.

We were told that wild songbirds could be bought in a nearby green space. It was easy to find.

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

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