2,500-year-old Bird's Nest Found in Greenland
Ornithologists from the University of Oxford discovered a 2,500 year old bird's nest on a cliff in Greenland. The nests belong to gyrfalcons - the largest species of falcon in the world - and is the oldest nest ever discovered.
They also found three other nests that are more than 1,000 years old and feathers from a bird that lived more approximately 670 years ago. The nest have been used by generations of gyrfalcons, who return on a regular basis.
To find out how old the nests were, Kurt Burnham of the University of Oxford carbon-dated guano and other debris in the nests. By analyzing the guano, scientists were also able to figure out what the gyrfalcons ate hundreds of years ago.
Those gyrfalcons living in central-west Greenland, which is farther from the ice sheet and nearer the ocean, fed from a diet much richer in marine animals, such as little auks and black guillemots.
"As a result of a warming and ameliorating climate other bird species, such as peregrine falcons, are moving further north," Burnham said to the BBC. "As peregrine populations continue to increase in density they will likely use more and more of these traditional gyrfalcon nests, forcing gyrfalcons to find alternate locations to nest in which may not offer the same amount of protection from the harsh Arctic environment in Greenland."
Gyrfalcons are not the only birds who return to their nests year after year for thousands of years.
By carbon dating solidified stomach contents, peat moss deposits and bone and feather samples from various moulting sites, researchers have in the past shown that colonies of snow petrel have returned to the same sites for 34,000 years and adelie penguins for 44,000 years