On the Trail Illegal Hunters Who Illegally Snare the Nation's Endangered Singing Birds.

The conservationist's vision darts across miles of open meadows, hunting for suspicious activity in the pre-dawn darkness.

He speaks in a hushed tone as we try to find a spot to hide in the fields. Behind us, the sprawling city of Beijing slumbers on. As we wait, we hear only the sound of breathing.

Suddenly, as the sky turns a shade lighter with the approaching day, the sound of footsteps emerges. Illegal trappers are present.

Caught

In the skies above us, countless migratory birds, some tiny enough that they can fit in the cup of a hand, are migrating south for winter.

They have utilized the long summer days in northern regions, consuming bugs and berries. As the year comes to a close and chilling gusts bring the early cold of winter, they head to more temperate climates to find food and shelter.

The nation hosts 1500-plus bird species, which is about 13% of the planet's species – over eight hundred of those are birds that migrate. Several of the major flyways they follow converge in China.

The area of meadow where we were, on the fringes of the Chinese capital, is an haven for small birds – any further and the city skies offer little opportunity to rest among clusters of concrete.

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

A net we almost encountered was extending over half the length of the field and supported with wooden sticks. At its center, a meadow pipit was struggling frantically to escape, but the more it moved, the more its claws became tangled.

This was a protected songbird, a protected bird in China, and an important "indicator species" – that means if its numbers are thriving, so is its environment.

Tracking the Trappers

This activist, carries out this mission for free using his personal funds. He has given up on many sleeping hours to release trapped birds, and he has spent the last 10 years persuading the police in Beijing to take this crime seriously.

"In the early days, no-one cared," he says.

So he enlisted helpers who did care and launched a group known as the Bird Protection Unit. He held community gatherings and brought in the officials of the relevant authorities. These small and persistent acts of persuasion seem to have paid off. The police discovered that catching poachers also led to identifying other kinds of illegal operations.

"It became clear our objectives became somewhat shared," Silva says, while pointing out that enforcement is still patchy.

Silva's love of birds began during childhood. He was raised in the nineties in a much changed capital.

He remembers exploring the fields on the city's edges where he discovered birds, frogs and snakes. "But starting from the 2000s, everything changed."

China's booming economy brought millions of rural workers to cities. This rapid urbanisation meant grasslands were considered empty places to build, not sanctuaries to preserve.

The transformation was alarming. The grasslands began to shrink, as did the habitats they supported.

"I made the choice back then to work in conservation and I chose this direction," he says.

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

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

He has also seen the departure of his army of volunteers over the years. This work demands covert operations and lost sleep. Silva says few people are willing to take on the challenging and occasionally risky job.

"My life is devoted to this," he says. "I made it a project because if you want to tackle this challenge, you must give it your all. You cannot be half-hearted."

He says donations covers some of the costs – over 100,000 yuan a year – but funding has declined because of the slowing economy.

So he has developed new ways to track the poachers.

He examines aerial photos to find the routes worn away by the poachers. He charts these against the birds' migratory routes and looks for areas where they may rest. The aerial views can even show netting setups which can capture hundreds of small birds during darkness.

"Siberian rubythroats and bluethroats sell for a premium," Silva says. "In big cities like Beijing and Tianjin, those who want to keep birds are now often affluent."

Although there are environmental regulations in place, Silva reckons the fines to deter the activity do not exceed the potential profits of trapping and trading songbirds.

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

It's a tradition that continues mainly among older individuals in their later years. Silva says some elderly citizens don't realise they are breaking the law, or grasp that so many more birds had to die in a trap for them to purchase a caged bird.

"These individuals didn't even have enough to eat in their youth. Now with some disposable income, they have adopted the habit and custom of keeping birds in cages," he says. "The nation progressed so fast, there was no time to raise awareness about the environment. Once people's attitudes are set, they're really hard to change."

Disrupted

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

Another man stands outside a nearby market holding a bird cage covered by a black veil. He informs passers-by quietly that his songbird is valuable, worth about 1900 yuan.

This is a glimpse of an old Beijing where small unofficial traders have established a niche trade.

The area alongside the water stretches for several miles and on a sunny weekday morning, there were shoppers browsing everything from old trinkets to dentures.

Information suggested that protected birds could be bought in a nearby green space. It was easy to find.

Music was blasting from a speaker under the low trees 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 dark cloth.

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