On a wing and a care
A curious crowd at the Summer Palace looked on with concern as nylon netting was stretched between the poles of the Spacious Pavilion, home to the largest urban population of the common Beijing swift.
A volunteer is letting go a Beijing swift after the banding. Photos by Liu Shuhai |
Volunteers from the Beijing Bird-watching society had gathered early last Saturday, preparing to catch the small birds for banding as part of a new research project.
But confused onlookers were alarmed to see these lovely birds captured - some even scolded the volunteers.
For years, the swift has been a familiar sight in the capital, soaring overhead in summer, or nesting in the eaves of ancient landmarks or even within those buildings.
Such is the city's fondness for the swift, it was the model for Nini, one of the five Fuwa mascots of next year's Olympic Games.
The swift is viewed by Beijing citizens as no different from other sorts of common swallows, according to Professor Gao Wu from Beijing Normal University, one of China's leading bird experts. And loving swallows has long been ingrained in the capital. To have a one nest under the eaves of a family's home is believed to be a potent symbol of good luck. The swallow's form is also used for one of the most popular children's kites.
But urban construction has taken a toll on local swift populations. With a dearth of nesting sites, their number has been steadily declining in the city over the past several decades.
The banding project conducted by Beijing Bird-watching Society is aiming to create a clear picture of its present status, with a view to halting its extinction.
At the Summer Palace on the weekend, Professor Gao was busy teaching each of the dedicated volunteers how to correctly band the birds.
Professor Gao Wu from Beijing Normal University is holding a captured Beijing swift in his hand. |
With an area of over 130 square meters, Spacious Pavilion is the largest of its type, octagonal with double eaves and overlooking a vast lake in the palace.
Within three hours, the volunteers had captured more than 30 swifts. The swifts would initially become entangled when they flew into the net. However, the volunteers used considerable skill and care to remove the swifts from the net, ensuring none were harmed.
"Strong wind and bright sunlight in the morning make the capturing work more difficult," said Fu Jianping, head of Beijing Bird Watching Society.
"Actually, the birds could see the net most of the time so they can cleverly keep away from it."
To the concerned laymen watching the work, Gao patiently explained that bird banding was one of the most useful tools in the study of wild birds.
The swifts are usually marked with a numbered metal band placed on the leg. The researcher then records information about the bird, including details of where and when it was banded.
Following its capture, each swift is given a "health check-up" by one of the volunteers capturing one swift, the volunteers need to give it a "health check-up". This examination covers the bird's weight, shape, color, and texture of feathers, color of bill, color and size of mouth and eyes.
Later, data from recovered bands provides a useful record of the distribution and movement of the bird, their relative numbers, annual production, life span, and causes of death.
"Such information increases our knowledge and understanding of the birds and helps us conserve them," Gao said.
Banding swifts in the Summer Palace started in 1997 but was suspended due to the outbreak of SARS in 2003.
The recent resumption of the bird-banding activity would raise public awareness of environmental protection in the lead-up to the 2008 Games, Fu said.
Already, banding has revealed some, said Gao. For example, the researchers captured the same bird for three consecutive years, which demonstrated the swift's strong will and ability to return to its birth place each year. The swift migrates to the Capital each March and leaves in August to spend the winter in the south.
Gao has paid particular attention to the city's swift since the 1950s. He blamed its population decline on the fast pace of urban construction. Many ancient city gate towers, once the most favorable nesting places for the swift, were demolished. These days, some remaining ancient buildings, such as the Forbidden City, were setting up protective nets around their eaves.
The swift was once found nesting in the nooks of steep cliffs, and is believed to have a biological demand for the height at which it lives. This explains the bird's fondness for nesting on the highest buildings in the cities when it later moved. The eaves of traditional Chinese building designs also sheltered the bird from wind and rain. However, this sort of architecture was largely discarded with the introduction of modern buildings.
But it is not all bad news for the little birds. Gao's recent observations have shown the swift's great adaptability, by choosing to nest in the holes of walls and some other lower places. This indicates a recovering trend for the population, Gao said.
In other hopeful developments, the construction of a tower for swifts to nest in the newly built Olympic Park was under discussion, and is pending approval by the municipal government.
Gao believed Beijing's swifts deserve such a special award from their human companions.
It is estimated that each time the birds fly out from this tower, they return to the nest holding in their mouths more than 200 worms to feed their young. Because the birds eat aphid, mosquitoes, and flies, increasing their numbers is an environmentally sound way to control insects and clean the city, said Gao.
(China Daily 05/17/2007 page20)
