Tourists gather at the Zhalong National Nature Reserve to witness the release of red-crowned cranes back to nature near Qiqihar in Heilongjiang Province on Thursday. /VCG Photo

Currently, there are about 2,000 wild red-crowned cranes in the world, about 300 of which live in the Zhalong reserve. /VCG Photo

Each year, four-year-old red-crowned cranes bred in captivity will be released into the wild in order to sustain the population. /VCG Photo