Wow - talk about living in an old house. When ornithologist Kurt Burnham of the University of Oxford and colleagues carbon dated the guano and other debris of a gyrfalcon nest in Greenland, he got a very surprising answer:
Carbon dating revealed that one nest in Kangerlussuaq in central-west Greenland is between 2,360 and 2,740 years old, the researchers report
Three other nests in the area are older than 1,000 years, with the youngest nest site first being occupied 520 to 650 years ago.
These ancient nests are still being regularly used by gyrfalcons.
"While I know many falcon species re-use nest sites year after year, I never imagined we would be talking about nests that have been used on and off for over 2,000 years," says Burnham.