The Momoge National Nature Reserve in northeast China's Jilin Province, the world's largest stopover site for migrating Siberian white cranes, has seen more than 1,500 of the birds arrive as of Sunday. The cranes spend over 100 days at the wetland of the nature reserve during their wintering migrations in spring and autumn annually, with the largest number reaching nearly 4,000, that's 90 percent of the total population of the species.