Another super-high flyer is Whooper Swans, which have been observed flying
as high as 29,000 feet(8839 meters).
For instance, the Whooper Swan, which as its name suggests is known
for making a bizarre honking sound, has been observed to sometimes make a noise as it expires.
Interestingly, the Whooper Swan is endemic to Greece, leading
some to speculate that someone in Ancient Greece heard one of these birds' dying sounds and subsequently exaggerated the event and attributed the same to all swans, thus giving rise to the legend.