Complex sentence: In North America it breeds in the Canadian Arctic Archipelago, Nunavut, Greenland (and to a lesser extent Alaska), in Eurasia it breeds Spitsbergen, and areas of northern Russia from the Taymyr Peninsula to the New Siberian Islands.
Split into simpler sentences: In North America, it breeds in the Canadian Arctic Archipelago, Nunavut, Greenland (and to a lesser extent Alaska). In Eurasia, it breeds Spitsbergen and areas of northern Russia from the Taymyr Peninsula to the New Siberian Islands.