HABITATS AND TOPOGRAPHIC FEATURES
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.