Much of the topography of North Dakota can be traced to the effects of
Wisconsin-age glaciation, particularly in the north and east. Large
portions of these glaciated areas are peppered by countless ponds and
lakes. A frightening number have been drained; nevertheless, these
wetlands constitute one of the most important waterfowl production areas
in the country.
Although North Dakota cannot boast of large mountain ranges like the
states farther west, it is anything but a flat, monotonous state. Much
of the state is characterized by gently rolling prairie. More noticeable
hills and escarpments may be found in the Turtle Mountains, Pembina
Hills, on the south side of Devils Lake, and along stretches of several
rivers (notably the Missouri). Further, beach lines and sandhills left
over from the last ice age provide a somewhat local variation to the
level topography of some areas. The most rugged terrain occurs in the
Little Missouri badlands, which are characterized by numerous steep
slopes, severely eroded buttes, and arroyos.
A large percentage of the state is occupied by agricultural land. This
category includes not only actively farmed land, but also retired
croplands, domestic hayfields, fence rows, wood lots (referred to as
tree claims), shelterbelts, orchards, and farmyards. While many of these
areas are almost devoid of wildlife, others provide suitable habitat for
a number of species.
Mixed-grass prairie is the predominant natural habitat, and it supports
the largest numbers of many of the prairie specialties which nest in the
state. Both tall-grass prairie and short-grass prairie also exist
locally.
A prairie habitat which is quite limited in the state is the
sage-prairie found in the southwest corner (primarily in the western
portions of Bowman and Slope Counties). Xeric in character, it is
composed mostly of buffalo and blue grama grasses peppered with sage
flats and clumps of prickly pear cactus.
Many prairie areas are punctuated by woody thickets, which host a number
of species that are characteristic of woodland-edge habitats. These
thickets are composed mostly of large shrubs (wolfberry and silverberry
are commonly found) in combination with a few small trees.
Wetlands occupy a major position on the list of habitats. Several types,
ranging from seasonal ponds and prairie marshes to permanent
wood-bordered lakes, are found here. Prairie wetlands are scattered
throughout the state, but are concentrated most densely in a broad belt
through the central and east-central portions. Permanent wood-bordered
ponds and lakes are mostly restricted to the Turtle Mountains.
Often associated with prairie wetlands are extensive wet meadows. These
are of primary interest to the birder because they support large numbers
of desired species such as Yellow Rail, Willow Flycatcher, Sedge Wren,
and Le Conte’s and Sharp-tailed Sparrows.
There are also several large alkaline lakes. Because of the high
salinity of the water and the adjacent salt flats, no emergent plants
are found, so they are not characterized by large numbers of breeding
birds. They do serve as excellent attractions to migrant shorebirds.
Very little of North Dakota is occupied by forest habitat, although it
is locally well-represented. Much of it is found in the form of
floodplain forests along the Red, James, Sheyenne, Souris, Missouri, and
Little Missouri Rivers and their tributaries. In the west the floodplain
forests are dominated, for the most part, by cottonwoods (as is true
along large portions of the Missouri and Little Missouri Rivers) and
have a more open canopy and understory than those of the eastern
streams.
In the east bottomland forests are represented by a more diverse plant
community. Among the more common trees are American elm, bur oak, green
ash, basswood, and box elder.
Tracts of upland deciduous forest can be found locally throughout the
state. In the southern and western portions, these are largely
restricted to buttes and bluffs overlooking various rivers. Bur oak,
green ash, and quaking aspen are usually the most representative trees.
(A good example can be found at Little Missouri State Park in Dunn
County.)
Upland deciduous forests also occur in the northeast. The best examples
are in the Pembina Hills of Pembina and Cavalier Counties. Smaller
tracts can be found on hills and bluffs overlooking many of the larger
lakes such as those around the shores of Devils Lake and Stump Lake.
Predominant trees include bur oak, American elm, quaking aspen, green
ash, box elder, and birch. The well-forested Turtle Mountains are
dominated for the most part by quaking aspen.
Small groves of evergreen forests dot the slopes and draws of the Little
Missouri badlands. These are represented by various species of junipers
and by ponderosa pine.
In addition to the natural habitats there are several artificial ones.
Agricultural areas, the largest group, have already been mentioned.
Others are urban areas—landscaped yards, gardens, golf courses, city
parks, cemeteries, and the almost-sterile downtown streets. Stock ponds,
reservoirs, and drainage ditches also constitute artificial
environments. An interesting man-made habitat (at least from the
birder’s view) is the municipal sewage ponds. These often attract an
incredible array of waterfowl and shorebirds and make excellent birding
spots for anyone who can put up with the smell.