FLIGHT OF THE CONDOR - In Ecuador and Peru the world's largest flying bird gets a helping hand.

The sun has just risen over the frosty brim of the Colca Canyon, high in the Andes of southern Peru. From mountaintop to roaring river, the canyon drops 11,000 feet, nearly twice as deep as the Grand Canyon. As the rays begin to slant into the chasm, which drops a dizzying 4,000 feet beneath my rocky perch, a tiny black-and-white speck appears far below, circling and growing in size as it approaches. An Andean condor is ascending on the first of the thermal air currents set in motion by the morning warmth.

Within minutes I find myself staring into an eye of the world's biggest flying bird. The adult male passes 15 feet before me, 33 pounds of body supported by expansive wings reaching 10.5 feet tip to tip. He banks and returns, white patches flashing on broad black wings, white ruff pulled snugly over his featherless neck. His splayed wingtip feathers make a whistling noise, not unlike wind in a sailing ship's rigging, as they slice the air.

For 22 years I have been waiting for an encounter like this, ever since my first distant sighting of an Andean condor circling high above an ice-clad volcano in Ecuador. Though only a dot in the sky, the legendary South American bird ignited my imagination. Now the creature is vanishing from many parts of its former mountain home, and my partner Mark Jones and I are here to photograph it and learn about two very different rescue schemes unfolding near the center of its range.

For many centuries the condor has been revered by Andean civilizations, appearing prominently in pottery, stone sculptures and even a gigantic figure etched into the desert surface of Peru's Nazca Plains. Yet much remains unknown about the birds. It is clear that they are formidable scavengers, the undertakers of the natural world. They quickly clean up the remains wherever death strikes, helping to prevent the spread of disease among large mammals in the process.

At the time of the Spanish conquest, the Andean condor's …