via 10,000 Birds
Gyrfalcons, those enigmatic raptors that can be found only on the fringes of the ABA area or in the imaginations of those birders farther to the south, have long mystified ornithologists looking to determine where, exactly, they go during the non-breeding part of the year. Certainly many in North America disperse into Canada and the northern United States annually, but until researchers from the High Arctic Institute, the University of Illinois US and the University of Oxford in the UK tagged 48 birds in Greenland with radio transmitters to monitor their movements, so much was still unknown. What they found was amazing:
Gyrfalcons living in the high Arctic overwinter out at sea, spending long periods living and hunting on pack ice.
It is the first time any falcon species has been found regularly living at sea.
The birds likely rest on the ice and hunt other seabirds such as gulls and guillemots, over what appears to be one of the largest winter ranges yet documented for any raptor.
"I was very surprised by this finding," said ornithologist Kurt Burnham who made the discovery. "These birds are not moving between land masses, but actually using the ice floes or pack ice as winter habitat for extended periods of time."
Pack ice is already known to be crucial habitat for other Arctic species, notably Polar Bear and Walrus. Now you can add Gyrfalcon to the list of charismatic species – perhaps the least expected – that depend on pack ice for at least part of the year.
photo by Francesco Veronesi via flickr (CC BY-NC-SA-2.0)