CHANGCHUN, April 11 (Xinhua) -- More than 500 oriental white storks have flocked to a national nature reserve in northeast China's Jilin Province.

The rare birds arrived at Boluohu Lake National Nature Reserve, alongside with more than 400 hooded cranes, 50 white cranes, more than 1,000 white-naped cranes and more than 200 whooper swans.

"At least 100,000 migratory birds under national protection have flocked here this year," said Wang Chenglin, with the nature reserve's management bureau.

Authorities in the reserve have stepped efforts to crack down on poaching, while improving the local environment, Wang said.

The oriental white stork is listed as endangered by the International Union for Conservation of Nature. The wild population is estimated at less than 5,000.