Birds in Xihu park in SE China's Fujian

An egret is seen on a tree at Xihu park in Fuzhou, southeast China's Fujian Province, March 18, 2018.

A kingfisher is seen on a tree at Xihu park in Fuzhou, southeast China's Fujian Province, March 18, 2018.

A european blackbird is seen on a tree at Xihu park in Fuzhou, southeast China's Fujian Province, March 18, 2018.

An oriental magpie robin is seen on a tree at Xihu park in Fuzhou, southeast China's Fujian Province, March 18, 2018.

BEIJING (AP) — Passersby in Beijing during winter or early spring might happen upon groups of residents playing fetch with birds. The players blow plastic beads into the air through carbon tubes for the birds — often from the migratory wutong species — to catch and return, in exchange for a treat.

It’s a Beijing tradition dating back to the Qing Dynasty, which ruled between the 17th century and early 20th century. Today, only about 50 to 60 people in Beijing are believed to still practice it.

Xie Yufeng, a 39-year-old cook, is one of them. Late Tuesday afternoon, Xie gathered with a few friends near Workers’ Stadium, where residents often congregate in the evenings to dance in tandem, practice tai chi or play the Chinese yo-yo.

Xie and his friends brought along their winged playmates — most of them wutong birds, with their distinctive yellow beaks and which fly southward from China’s northeast to Beijing every fall to escape the bitter winter.

Domesticating the birds and training them for the bead-catching game may take four to five months, Xie said. Players teach the birds to fetch by first throwing seeds into the air, and later replacing them with plastic beads. Every time the birds retrieve the beads, they are rewarded with a snack. In the past, the beads were made of bone.

“In order to do this well, patience is the most important quality for a player,” Xie said.

The tradition is said to have taken root in the capital with the arrival of the Qing Dynasty, a Manchu group that took control of Beijing in the mid-1600s.

Manchu nobles, living around the Forbidden City, are believed to have popularized catching and training birds as a pastime.

Today, residents of Beijing’s traditional alleyways, called hutong in Chinese, often still raise birds in cages and may even take the whole birdcages out for walks.

The wutong bird owners usually release them in late spring and allow them to migrate back to the northeast — only to catch or purchase new ones the following fall.

Mistreanu reported from Taipei, Taiwan. AP researcher Yu Bing contributed to this report.