In this undated photo provided by Facundo Vital in July 2020, an Andean condor soars above the Patagonian steppe in Argentina. To birds, the sky is not empty, but a landscape of invisible features – ...

Talk about the path of least resistance. An observation from a recent study on flight habits of large birds followed an Andean condor that soared in the skies for 100 miles without having to flap its ...