Canada (NB) (P), China (mainland), Finland (B) (NB), France, Greenland (B) (NB), Iceland (B) (NB), Japan, Mexico, Norway (B) (NB), Russia (Asian) (B), Russia (Central Asian) (B) (NB), Russia (European) (B), Sweden (B) (NB), USA (B).
Vagrant to Austria, Belgium, Brazil, Czech Republic, Denmark, Estonia (NB), Germany, Ireland, Kazakhstan, Kyrgyzstan, Latvia, Netherlands Antilles, Pakistan, Poland, Portugal, Spain, St Pierre and Miquelon (NB) (P), Svalbard and Jan Mayen Islands, Switzerland, Ukraine, United Kingdom.
Circumpolar, occupying Arctic regions of Eurasia, North America, Greenland and Iceland; some birds move farther southern for winter.
Population
Estimated population is 110,000 (2010).
Usually considered monotypic, but highly polymorphic. Sometimes considered polytypic, normally with four subspecies, based mainly on colour frequencies: rusticolus (Europe); obsoletus (Asia, parts of North America); candicans (high Arctic of North America, Greenland); and finally islandus (Iceland), the most isolated, uniform and distinctive of these forms, which would probably be most valid subspecies.
Morph altaicus of Saker Falcon (Falco cherrug) has been listed as subspecies of present species; also considered to form link between these two species.
The Reader's Digest Book of British Birds 1980, 3rd Edition, Drive Publications Ltd ISBN 0 340 25308 8
Birds in Colour Campbell, B., 1960, Penguin Books Ltd
The Pocket Guide to Nest and Eggs Fitter, R.S.R., 1954, Collins
RSPB Handbook of British Birds Holden, P., Cleeves, T., 2002, A & C Black ISBN 0 7136 5713 8
Birds of Britain and Europe Sterry, P., et al., 2001, AA Publishing ISBN 0 7495 3068 5
The Popular Handbook of British Birds Hollom, P.A.D., 1973, H.F. & G. Witherby Ltd ISBN 0 85493 002 7
BirdLife International Species Factsheet