Shout it from the rooftops
Why birders are a rare breed
Among the capitals of big economies, Beijing enjoys a surprising distinction.
Despite its sometimes harsh weather and chronically polluted air, it hosts more species of birds than any other such city apart from Brasília.
Remarkably, however, birdwatching remains uncommon.
In many countries, birders play an important role in spotting changes in bird populations and avian behaviour.
A British enthusiast in Beijing, Terry Townshend, has recently set up a means of doing so without needing to stand for hours outdoors.
It involves a digital listening device, installed on the roof of a 15-storey building in northern Beijing.
For several months until mid-November it recorded the night-time calls of migratory birds flying above.
The sounds will be used to identify night-flying species, some of which are not commonly seen overhead by day.
The technique has been used in America and Europe, but Mr Townshend thinks this is its first known application in Asia.
Such dedication is rare among amateurs.
China has little history of birdwatching.
Only in the 19th century, led by Western ornithologists, did the scientific study of birds begin.
Birdwatching as a pastime has emerged only in the past two decades, helped by rising incomes that have allowed people to buy spotting scopes, binoculars and cameras.
In other countries, enthusiasts have played a big role in drawing public attention to human threats to birds.
Chinese officials sometimes pay attention to gentle recommendations about ways to improve the environment.
But they frown on activism.
So harm caused to birds or their habitats can go unremarked.
One British birder laments the recent draining of supposedly protected paddies by the Wenyu, a river in Beijing that had been a place of rest for about 200 migratory species.
Birdwatching groups in China mostly avoid campaigning.
Many of their members stick to taking photographs and do not even bother with binoculars.
There is, however, a small but growing number of local birders who closely monitor bird migration.
Mr Townshend's listening device may provide other valuable insights.
He plans to install more.