Following Poachers That Illegally Capture China's Endangered Wild Birds.

The conservationist's vision darts across miles of tall grassland, searching for signs of life in the inky blackness.

He utters a hushed tone as the team seeks a spot to hide in the grasslands. Behind us, the vast metropolis of Beijing remains asleep. As we wait, the only sound is the sound of breathing.

Suddenly, as the sky starts to lighten before dawn, there is the crunch of footsteps. The hunters have arrived.

Caught

Overhead, a multitude of winged travelers, many so small that they could rest in the cup of a hand, are traveling to the south for winter.

They have benefited from the long summer days in northern regions, consuming bugs and berries. As the year nears its end and cold breezes bring the initial freeze of winter, they head to southern locales to find food and shelter.

China is home to 1500-plus bird species, which is about 13% of the planet's species – over eight hundred of those are birds that migrate. Four of the nine major migration routes they follow converge in China.

This particular field being monitored, on the fringes of the Chinese capital, is an refuge for small birds – any further and the city skies offer few options to rest among towering rows of concrete.

It is equally attractive for the poachers and their "barely visible nets", so thin you can almost miss them.

The one we nearly walked into was stretched across half the length of the field and supported with wooden sticks. In the middle, a small finch was struggling frantically to free his legs, but the more it moved, the more its feet got ensnared.

This was a meadow pipit, a protected bird in China, and an important "indicator species" – that means if its population is healthy, so is its ecosystem.

Hunting the Hunters

This activist, performs this duty for free using his own savings. He has sacrificed many nights of sleep to rescue birds, and he has spent the last decade persuading the police in Beijing to enforce the law.

"In the early days, there was little interest," he remarks.

So he enlisted helpers who were concerned and established a group called the Bird Protection Unit. He held community gatherings and invited the officials of the local police and forestry bureau. These small and persistent acts of persuasion seem to have paid off. The police discovered that catching poachers also helped in tracking down other kinds of criminal activity.

"It became clear our goals were partially aligned," Silva says, adding the caveat that the response is not uniform.

His passion for avian life started in childhood. He grew up in the nineties in a very different Beijing.

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

Industrialization brought millions of rural workers to cities. This fast-paced development meant grasslands were considered empty places to build, not conservation areas to preserve.

The transformation was alarming. The grasslands began to shrink, as did the wildlife they housed.

"I decided back then to pursue environmental protection and I followed this course," he says.

This has not made for an easy life. One of Beijing's biggest bird dealers discovered he was being investigated by Silva and retaliated.

"He gathered several of his accomplices who surrounded 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 team of helpers over the years. This work requires 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 treat it as a mission because if you want to solve this big problem, you must devote yourself wholeheartedly. You cannot be half-hearted."

He says fundraising pays for some of the costs – over 100,000 yuan annually – but funding has declined 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 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 scores of small birds during darkness.

"Certain prized species sell for a high price," Silva says. "In urban centers like Beijing and Tianjin, those who want to keep birds are now quite wealthy."

Although there are wildlife laws in place, Silva believes the penalties to deter the activity do not outweigh the financial benefits of trapping and trading songbirds.

Keeping a caged bird was – and for some people in China, still is – a mark of prestige. This dates back to the imperial era. Wealthy individuals would build ornate bamboo cages for their birds.

This custom that persists mainly among retired men in their later years. Silva says older Chinese people may not understand they are breaking the law, or understand that so many more birds were killed in a trap for them to purchase a caged bird.

"This generation often lacked enough to eat growing up. Now with a little money, they have adopted the practice of caging birds," he says. "China developed so fast, there was no time to raise awareness about ecology. Once adults' values are formed, they're really hard to change."

Apprehended

On a long low wall in Beijing, a trader has several small cages with tiny twittering birds.

A separate individual stands outside a local market holding a bird cage shrouded in a black veil. He tells passers-by quietly that his songbird is valuable, worth nearly 1900 yuan.

This is a glimpse of an traditional side of the city 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 people looking at everything from vintage jewellery to dentures.

We were told that protected birds could be purchased in a nearby green space. It was easy to find.

Loud music played from a speaker under the low trees where a group of elderly ladies were performing a fan dance. Nearby several men, all in their later years, had congregated with bird cages – some had two or three in their hands. Most were covered in dark cloth.

But today there would be no transactions because the police had appeared. They were interviewing the bird owners and recording details. Defiant, one man claimed he was {taking his caged bird for a walk|simply exercising his