[Mark in the Old South]

I seem to remember reading somewhere about a huge eagle that lived on the west coast of South America that was much larger, approaching the size of a small plane. They thought is went extinct because of the reduction of strong air currents that the bird required to get into the air. I think they were thought to feed on large fish. Sorry I can not remember more and even this is relying on faulty outdated data systems (my old noggin)

[Bloody Sam Roberts]

...approaching the size of a small plane.

Must be the Roc of ancient legend.