They are among the world's more engaging birds, with vanilla-white stomachs, dark throats, and bodies that arc down from their wings at takeoff like giant commas. They are also among the rarest: only an estimated 700 to 900 black- necked cranes survive in the wild, most of them living on the 10,000-ft.- high plateaus in the northwestern region of Tibetan China. As humans encroach on their nesting and wintering grounds, the number of birds continues to dwindle, and officials of the People's Republic of China fear that the species may become extinct.
Now China is acknowledging that the best hope for...