Northern Prairie Wildlife Research Center
Figure 2. Biotic areas of North Dakota.
Because of the high fertility of the soils, agricultural development has modified nearly all of the arable acreage within the region. Only a few small remnant tracts of the original climax tall-grass prairie remain. Large expanses of cropland are prevalent throughout. The principal crops are small grains (chiefly wheat), corn, potatoes, sugar beets, soy beans, and sunflowers. The monotony of these extensive, drab, monotypic habitats is relieved by occasional narrow bands of flood-plain forest along some of the larger streams. Brushy open woodlands that adjoin tracts of a distinct, sparsely vegetated type of prairie also occur on the limited areas of deltaic sand. In addition, wooded habitats established by man--including tree-claims, shelterbelts, and landscaped yards--are found in the vicinity of farmsteads, towns, and city suburbs. Wetland habitats in this region include streams and associated oxbows, and a few widely scattered ponds and marshes.
The breeding birds are dominated by upland, pandemic species of the North-central Avifauna in association with many species of the Eastern Avifauna. In addition, a few species of the Northern Avifauna and two species of the Western Avifauna (Western Kingbird and Brewer's Blackbird) are of regular occurrence.
The characteristic breeding birds may be categorized according to relative abundance and include 6 primary species that are often common or abundant, 29 secondary species that are usually fairly common, and 78 tertiary, or minor, species that are uncommon or rare. The primary and secondary species are listed as follows:
Mourning Dove Horned Lark Common Crow Western Meadowlark Common Grackle Brown-headed CowbirdSecondary Species
Red-tailed Hawk Starling American Kestrel Warbling Vireo Killdeer Yellow Warbler Black-billed Cuckoo Common Yellowthroat Great Horned Owl House Sparrow Yellow-shafted Flicker Bobolink Eastern Kingbird Red-winged Blackbird Western Kingbird Baltimore Oriole Barn Swallow American Goldfinch Blue Jay Dickcissel (local) House Wren Savannah Sparrow Brown Thrasher Vesper Sparrow Gray Catbird Clay-colored Sparrow American Robin Song Sparrow Cedar Waxwing
Throughout the Drift Plain, gently rolling ground moraine is the prevalent glacial land form. Locally, fairly extensive areas of lake plain occur including the Souris Lake Plain in Bottineau and McHenry Counties, the Devils-Cando Lake Plain in Ramsey and Towner Counties, and the Dakota Lake Plain in Dickey and Sargent Counties. In addition, other land forms including dead-ice moraine, end moraine, glacial outwash, deltaic sand, kame, and esker are of local importance. In certain areas, deep glacial meltwater channels, often called coulees, are prominent along some of the major streams and their tributaries.
On the Missouri Coteau, dead-ice moraine, which is characterized by knob-and-kettle topography, is generally prevalent. Large areas of glacial outwash also are present, particularly in Kidder and McLean Counties. End moraines are prominent in certain portions of the Missouri Coteau, and small areas of ground moraine, lake plain, deltaic sand, kames, and eskers occur. The natural basin wetlands on the Missouri Coteau average somewhat larger and deeper than those on the Drift Plain and contain surface water that tends to be of greater permanence. On glacial outwash areas, the wetlands are often quite distinctive, being much more saline than those found elsewhere.
Four distinct biotic subregions that may be recognized within the Prairie Pothole Region are based on proportional variations in area of glacial land forms and differences in environmental conditions and biogeographical relationships. These are referred to as the Northeastern, Southern, and Northwestern Drift Plains, and Missouri Coteau (Fig. 2).
The climax biotic community of the Prairie Pothole Region is represented by the eastern mixed-grass prairie. Fairly extensive tracts of this type of native prairie, often heavily grazed, still exist, particularly on areas of end moraine, dead-ice moraine, glacial outwash, and on kames and eskers. Locally, isolated tracts of tall-grass prairie are present in well-drained lowlands near pond margins, along intermittent streams, and on north- or east-facing slopes of hills. Small disjunct areas of western mixed-grass prairie also occur on the summits and upper slopes of the higher morainic hills.
On ground moraine and on many tracts of other glacial land forms, the natural grasslands have been largely destroyed by man and replaced by very extensive acreages of croplands. The principal crops in the region are wheat, oats, barley, and flax; while fairly large corn fields and alfalfa or sweetclover hayfields may be found locally.
Habitats of major importance in the region also include a considerable variety of shallow basin wetlands (Stewart and Kantrud 1971). Other habitats of local importance are fluviatile and man-made wetlands, isolated small tracts of deciduous forest, and residential areas of man. Fluviatile wetlands include permanent and intermittent streams and their associated oxbows; man-made wetlands are represented by stock ponds, dugouts, large shallow-stream impoundments, reservoirs, and sewage lagoons. Deciduous forests include narrow bands of floodplain forest along the Sheyenne, James, and Mouse rivers and their tributaries; local upland forests on river bluffs and high moraines and along margins of permanent lakes; scattered thickets of small trees or aspen groves on the prairie; and tree-claims, shelterbelts, and other wooded habitats established by man. The partially wooded residential areas of man are commonly represented by farmsteads, towns, and city suburbs.
The breeding birds are composed preponderantly of upland and wetland species that are characteristic of the North-central Avifauna, including endemic and pandemic species. Species typical of the Eastern Avifauna are fairly prominent along permanent streams and in other wooded habitats on the Northeastern and Southern Drift Plains but occur more sparingly elsewhere. Small local populations of a few species that belong to the Western and Northern Avifaunas also occur in this region.
The characteristic breeding birds of this region include 16 primary species, 52 secondary species, and 79 tertiary, or minor, species. The primary and secondary species are listed as follows:
Gadwall Horned Lark Mallard Western Meadowlark Pintail Red-winged Blackbird Blue-winged Teal Yellow-headed Blackbird Northern Shoveler Brown-headed Cowbird American Coot Savannah Sparrow Black Tern Clay-colored Sparrow Mourning Dove Chestnut-collared LongspurSecondary Species
Eared Grebe Yellow-shafted Flicker Pied-billed Grebe Eastern Kingbird American Bittern Western Kingbird Black-crowned Night Willow Flycatcher Heron Bank Swallow American Wigeon Barn Swallow American Green-winged Cliff Swallow Teal Common Crow Canvasback House Wren Redhead Long-billed Marsh Wren Ruddy Duck Brown Thrasher Swainson's Hawk Gray Catbird Red-tailed Hawk American Robin Marsh Hawk Sprague's Pipit Sharp-tailed Grouse Cedar Waxwing Ring-necked Pheasant Yellow Warbler Gray Partridge Common Yellowthroat Sora House Sparrow Killdeer Bobolink Upland Plover Common Grackle Willet American Goldfinch Marbled Godwit Lark Bunting American Avocet Baird's Sparrow Wilson's Phalarope Grasshopper Sparrow Franklin's Gull Vesper Sparrow Ring-billed Gull Song Sparrow Black-billed Cuckoo Great Horned Owl
The gently sloping terrain of the Coteau Slope has been slightly to moderately affected by past glaciation. Sheet moraine and shallow ground moraine deposits are the principal glacial land forms throughout. Small areas of dead-ice moraine, end moraine, outwash plain and lake plain also occur. Drift-free, water-eroded exposures of sedimentary bedrock are quite common along bluff escarpments of stream valleys. Relief is generally low to medium except near such exposures, where typical badland topography is apparent. Other formations occur along the Missouri River Trench where dissected valley walls and broad bottomland alluvial deposits have developed. Locally, a few scattered, shallow, natural basin wetlands are present on the gently sloping uplands.
The Missouri Slope is largely unaffected by glaciation, being entirely unglaciated in the western portion, while in the eastern half only a few small scattered remnants of sheet moraine are indicative of past glaciation. The broad, rolling uplands of this subregion are interrupted by bedrock valleys along many of the larger streams and by a few scattered high buttes. Locally, along the Cannonball and Heart rivers, small areas of badlands also have developed.
Within the Little Missouri Slope the wide, rugged badlands along the Little Missouri River and its tributaries represent the most prominent topographic feature. These picturesque formations are adjoined by broad, rolling uplands that contain many conspicuous high buttes. In the southern portion of the subregion, particularly in western Bowman County, other formations caused by shallow, surface erosion closely resemble the bleak "scablands" of eastern Washington.
The climax biotic community in the Southwestern Slope Region is represented by the western mixed-grass prairie association. This community could be described as an ecotone between the eastern mixed-grass prairie and typical short-grass prairie. Large expanses, usually grazed by livestock, are still present, although the total acreage is steadily being reduced in many areas because of the encroachment and expansion of vast areas of cropland. In this region, wheat is the principal agricultural crop.
Other more localized grassland communities also are fairly important in this region. In many lowland areas that occur in draws or near intermittent streams, typical eastern mixed-grass prairie is the prevalent type. Sizable tracts of short-grass prairie often are present on the more elevated uplands, especially within the Little Missouri Slope. In the southern portion of the Little Missouri Slope, an xerophytic grassland community, referred to as "black sage prairie", also is quite common.
A "badlands community complex" that may be described as a mosaic mixture of grassland, brushland, and sparsely vegetated eroded slopes is especially characteristic of all badland areas and often is quite extensive. Other natural habitats of local importance include thickets of small trees and shrubs in upland prairie draws, bands of floodplain forest along the larger streams, and scattered small tracts of western coniferous forest that are largely restricted to the southern half of the Little Missouri badlands. Certain wooded or partially wooded habitats created by man also have an appreciable influence on wildlife. These include shelterbelts, farmsteads, and residential areas in towns and cities. Wetland habitats, of limited importance in this region, include fluviatile wetlands, stock ponds, dugouts, and reservoirs.
In general, the breeding birds are dominated by upland species of the North-central Avifauna in association with many species of the Western Avifauna. Species characteristic of the Eastern Avifauna are fairly prominent locally, particularly in woodland habitats along permanent streams. Also, a few species of the Northern Avifauna are of rare occurrence in this region.
The characteristic breeding birds include 8 primary species, 28 secondary species, and 93 tertiary species. The primary and secondary species are listed as follows:
Sharp-tailed Grouse Mourning Dove Horned Lark Western Meadowlark Brown-headed Cowbird Lark Bunting Grasshopper Sparrow Chestnut-collared LongspurSecondary Species
Mallard American Robin Pintail Loggerhead Shrike (local) Marsh Hawk Yellow Warbler American Kestrel (local) House Sparrow Ring-necked Pheasant Red-winged Blackbird Gray Partridge American Goldfinch Killdeer Dickcissel (local) Common Nighthawk Lazuli Bunting (local) Yellow-shafted Flicker (local) Spotted Rufous-sided Eastern Kingbird Towhee Barn Swallow Vesper Sparrow Cliff Swallow Lark Sparrow Black-billed Magpie Clay-colored Sparrow House Wren Field Sparrow Brown Thrasher
The prevailing biotic community on undisturbed soils is a type of northern deciduous forest that is usually dominated by quaking aspen. Other species of deciduous trees that are commonly associated with quaking aspen include balsam poplar, paper birch, bur oak, and green ash. It is probable that this forest type does not represent a true climax community, but is instead a subclimax community that has been maintained because of occasional, severe forest fires. This theory is supported by the fact that this type of forest closely resembles fire subclimax communities in the boreal forest region toward the north.
Fairly large tracts of forest have been cleared by farmers, and these areas are now devoted to intensive agriculture. Many of the forested areas that still remain have been cutover or burned; and, consequently, various successional brush stages are often prevalent.
Natural basin wetlands are especially numerous in this region and include many fairly deep permanent ponds and lakes as well as large numbers that may be classified as temporary, seasonal, or semipermanent. Swamps that are dominated by shrubs or trees also occur frequently. Other habitats of local significance include farmsteads and residential resort areas on some of the larger fishing lakes.
The predominant breeding birds may be represented as a mixture of species that typify the North-central and Eastern Avifaunas. A fairly large population of Northern Avifaunal species is of regular occurrence, and very limited numbers of five species of the Western Avifauna (Turkey Vulture, Western Kingbird, Black-billed Magpie, Mountain Bluebird, and Brewer's Blackbird) are present.
The characteristic breeding birds of this region include 19 primary species, 54 secondary species, and 60 tertiary species. The primary and secondary species are listed as follows:
(including well-marked subspecies)
Mallard Veery Blue-winged Teal Red-eyed Vireo Broad-winged Hawk Yellow Warbler Red-tailed Hawk American Redstart Ruffed Grouse Red-winged Blackbird Yellow-bellied Sapsucker Brown-headed Cowbird Yellow-shafted Flicker Baltimore Oriole Least Flycatcher Rose-breasted Grosbeak Common Crow Clay-colored Sparrow American RobinSecondary Species
Common Loon Ruby-throated Red-necked Grebe Hummingbird Horned Grebe Hairy Woodpecker Eared Grebe Eastern Kingbird Pied-billed Grebe Willow Flycatcher Double-crested Cormorant Tree Swallow American Bittern Purple Martin American Wigeon Barn Swallow American Green-winged Black-capped Chickadee Teal House Wren Northern Shoveler Long-billed Marsh Wren Canvasback Short-billed Marsh Wren Redhead Brown Thrasher Ring-necked Duck Gray Catbird Ruddy Duck Cedar Waxwing Cooper's Hawk Warbling Vireo Marsh Hawk Northern Waterthrush Sora Common Yellowthroat American Coot Mourning Warbler Killdeer Bobolink Spotted Sandpiper Western Meadowlark Wilson's Phalarope Yellow-headed Blackbird Black Tern Common Grackle Mourning Dove American Goldfinch Black-billed Cuckoo Savannah Sparrow Great Horned Owl Vesper Sparrow Common Nighthawk Chipping Sparrow Belted Kingfisher Song Sparrow