Through the study of three different skeletons from the late Miocene epoch, the largest flying bird to have ever existed was discovered. Argentavis magnificens (translated: magnificent Argentine bird) was so gargantuan, the standing height would be around 6 feet high!
With a wingspan of 21 feet across and a weight of about 160 pounds, this beast would have had trouble taking flight from ground level. In fact, that is one thing that scientists were puzzled about. Argentavis had the power necessary to run, but its wings would have been so large, the flapping motions would just hit the ground. Even in flight, the wings would have been to heavy to flap consistently, otherwise the bird would grow exhausted! How could this creature have wings formed for flight, but not use them? The answer arrives from where these specimens were discovered: the Andean foothills of Argentina.
If this bird lived in the Andes, flight becomes much more accessible. With a run towards the edge of a slope or cliff, Argentavis could begin flapping its wings as it left the side of the mountain. During the late Miocene, this area was also more dry and warm which means thermal currents could have been utilized by this bird as well. It would glide across peaks, looking for food on the mountain sides. And with new data from simulations, scientists have estimated that this bird could fly at speeds of up to 150 miles per hour!
Finally, because they had no known predators, Argentavis birds would have led long lives. The only cause of death would be disease or old age and the actual mortality rates seem to have been fairly low. Today’s estimates place their lifespan at 50 to 100 years at most. Why it became extinct could be any number of reasons, including changes to food supply and climate.