Condor uses 5 times less energy than swan per kilometer of flight

New research on wild birds has overturned a decades-old scientific paradigm about the energetic costs of flight. The California condor and trumpeter swan have similar mass, yet the condor uses only 20% of the swan's energy to cover 1 km. The secret lies in exploiting air currents — the condor flaps its wings for merely 0.1% of its flight time, while the swan does so 99% of the time.