Beijing swifts have lived up on the Zhengyangmen Gate for over 600 years. Many Beijingers grew up with the chirping of swifts. A group of researchers are taking care for these cute little guys, observing them build nests, inhabit, migrate in July and return in next April.

(Flavor of Beijing series is presented by the Information Office of the People's Government of Beijing Municipality and produced by Beijing Radio & Television Station.