Arctic
Plains & Mountains
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This region includes
low-lying, coastal tundra and drier uplands of the Arctic mountains
across the entire northern edge of North America. Because of thick and
continuous permafrost, surface water dominates the landscape (20-50
percent of the coastal plain). Freezing and thawing form a patterned
mosaic of polygonal ridges and ponds, and many rivers bisect the plain
and flow into the Arctic Ocean. The ocean surface is generally frozen 9
to 10 months of the year, and the ice pack is never far from shore.
Because of the wetness, waterfowl and shorebirds dominate the avian
community and passerines are scarce. The most abundant breeding birds on
the coastal plain include Northern Pintail, King Eider, Oldsquaw,
American Golden-Plover, Semipalmated Sandpiper, Pectoral Sandpiper,
Red-necked Phalarope, and Lapland Longspur. Several Old World species,
including the Arctic Warbler and Bluethroat, penetrate the region from
the west. Taiga passerines, such as Gray-cheeked Thrush and Yellow
Warbler, reach the region along drainage systems and raptors, including
Gyrfalcon and Rough-legged Hawk, nest commonly along major rivers. Few
bird species winter in the region. |