Habitat
During the breeding season on medium to large lakes where there are plenty of fish. Outside the breeding season on coastal waters and very occasionally large inland lakes and reservoirs.
Unknown to Austria (NB), Bulgaria (NB), Czech Republic (NB), Germany (NB) (P), Italy (NB), Romania (NB), Slovakia (Slovak Republic) (NB), Slovenia (NB), Sweden (NB), Switzerland (NB), Ukraine (NB).
Mainly Nearctic, where breeds between 48° northern and Arctic Circle, in places south to c. 40° north, and north to c. 78° N; in northern Atlantic also breeds in Greenland, Iceland, Bear I and very occasionally Scotland. Winters mainly along coasts of northern Atlantic and north-eastern Pacific, also stopping off in Great Lakes.
 
Population
Estimated population is 610,000 - 640,000 (2010).
Common Loon (Gavia immer) [XC535054]
by Betchkal, Davyd from , United States (call)
Common Loon (Gavia immer) [XC569715]
by Panvert Robin from Hyland Lake Park Reserve - Recreation Area (near Bloomington), Hennepin County, Minnesota, United States (flight call)
Nest
Either directly on the ground or on a heap of water-weeds, close to water, having a characteristc slipway leading to it from the water.
Eggs (Guide)
Usually 2; dark brown to olive, with a few dark spots; cylindrical. Incubation: about 30 days; by both sexes.
Young
Fledge in about 60 - 65 days.
Subspecies
Hybridization with Arctic Loon (Gavia arctica) reported.
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