A double wildlife treasure has been discovered on Chongming Island.

Two national first-level protected animals, the white stork and the relict gull, or Larus relictus, are spending the winter on the island's Jiuduansha wetland nature reserve.

Reserve officials said it is the first time the white stork has been recorded in the area. The bird mostly lives in eastern Asia, and its global population is less than 3,000. "White storks usually spend winter in Boyang Lake in Jiangxi Province," said a researcher, Chen Xiuzhi. "This one probably lost its way during the trip. But the discovery of the bird showed the wetland is suitable for the species to spend winter."

The white stork is regarded as a lucky bird, and legend says it delivers babies.

The relict gull was first discovered in the area in 2005.

This species has a small, declining population as a result of predators, human disturbance, and variable climate at breeding colonies.

In addition to the two protected birds, the red-throated diver, or Gavia stellata, has also appeared at the reserve these years.

"Most birds only stay here for several months of winter or summer," Chen said, adding that illegal hunting is a problem.

The nature reserve was set up in 2000. It occupies 420 square kilometers, and hosts 169 species of birds.

(Source: www.shanghai.gov.cn )