SIERRA PAILEMAN, Argentina (AP) — It was a sunny morning when about 200 people trudged up a hill in Argentina’s southern Patagonia region with a singular mission: free two Andean condors that had been born in captivity.

While members of the Mapuche, the largest Indigenous group in the area, played traditional instruments, and a group of children threw condor feathers into the air that symbolized their good wishes for the newly liberated birds, an eerie silence engulfed the mountain in Sierra Paileman in Rio Negro province as researchers opened the cages where the two specimens of the world’s largest flying bird were kept.