I hope this isn't too far off-topic but I came across a couple fascinating new(ish) findings about Gyrfalcon, a rare and much lusted after vagrant to New York.
First, tracking studies by Dr. Kurt Burnham (High Arctic Institute, Illinois US and the University of Oxford, UK) and Dr. Ian Newton (Centre for Ecology and Hydrology, Oxford University, UK) of Gyrs nesting in Greenland has revealed that some effectively winter at sea. These studies will be published in the July issue of The Ibis [Burnham, KK and I Newton (2011) Seasonal movements of Gyrfalcons Falco rusticolus include extensive periods at sea. Ibis 153(3): 468-484]. A juvenile female in their study population traveled more than 2,800 miles (4,500 km) over 200 days, spending more half that time over the ocean between Greenland and Iceland. Now of course these are areas of winter pack ice and the birds can land on the ice, but still it's an extraordinary adaptation for a non-waterbird. It makes sense that they might follow alcids such as Black Guillemot and various gulls that exploit the edges of the sea ice as their winter habitat. Like Peregrines, Gyrfalcons engage in long over-water flights and there are a number of records of white-morph (Greenland) birds coming aboard ships in the North Atlantic, closer to Europe than Greenland. Second, the same team have shown that generations of Gyrfalcons use the same nesting ledge for hundreds if not thousands of years. Carbon dating of the guano (evidently an extensive mound) in active nests has put the usage of one site as far back as 2,360 to 2,740 years. They even dated a Gyrfalcon feather to 670 years (I guess that would count as a family heirloom). Unfortunately, this amazing continuity is threatened by the radical changes in climate that are occurring in Greenland at the present time. Again, the primary data was published in The Ibis [Burnham KK, Burnham, WA and I Newton (2009) Gyrfalcon Falco rusticolus post-glacial colonization and extreme long-term use of nest-sites in Greenland. Ibis 151:514-522]. You can read more details of these fascinating stories here http://www.bbc.co.uk/nature/13791688 http://news.bbc.co.uk/earth/hi/earth_news/newsid_8103000/8103872.stm -- Angus Wilson New York City & The Springs, NY, USA http://birdingtotheend.blogspot.com/ -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L 3) http://birdingonthe.net/mailinglists/NYSB.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
