Why might an Andean Condor require beneficial air currents to sustain flight?

Answer

Due to its heavy weight, often over 30 pounds

The Andean Condor can weigh over 30 pounds, and this significant weight necessitates the use of beneficial air currents to maintain flight.

Why might an Andean Condor require beneficial air currents to sustain flight?
behaviorbirdaggressionwildlifecondor