Bird Conservation Regions Map
- Aleutian/Bering Sea Islands
- Western Alaska
- Arctic Plains and Mountains
- Northwestern Interior Forest
- Northern Pacific Rainforest
- Boreal Taiga Plains
- Taiga Shield and Hudson Plain
- Boreal Softwood Shield
- Great Basin
- Northern Rockies
- Prairie Potholes
- Boreal Hardwood Transition
- Lower Great Lakes/St.Lawrence Plain
- Atlantic Northern Forests
- Sierra Nevada
- Southern Rockies Colorado Plateau
- Badlands and Prairies
- Shortgrass Prairie
- Central Mixed Grass Prairie
- Edwards Plateau
- Oaks and Prairies
- Eastern Tallgrass Prairie
- Prairie Hardwood Transition
- Central Hardwoods
- West Gulf Coastal Plain/Ouachitas
- Mississippi Alluvial Valley
- Southeastern Coastal Plain
- Appalachian Mountains
- New England/MidAtlantic Coasts
- Peninsular Florida
- Coastal California
- Sonoran and Mojave Deserts
- Sierra Madre Occidental
- Chihuahuan Desert
- Tamaulipan Brushlands
- Gulf Coastal Prairie
Bird Conservation Region 1 – Aleutian/Bering Sea Islands
Included in this region are the Aleutian Islands, extending westward from the Alaskan mainland for 1,100 miles, and the Bering Sea islands, including the Pribilofs, St. Matthew, Hall, St. Lawrence, and Little Diomede. The Aleutian chain is volcanic in origin, with a maritime climate in which wind is ever present. Vegetation at higher elevations consists of dwarf shrub communities, mainly willowand crowberry. Meadows and marshes of herbs, sedges, and grasses are plentiful, and some islands have ericaceous bogs. Sea ice does not extend to the Aleutians and permafrost is generally absent; however, sea ice is an important feature of the Bering Sea. Seabirds are a dominant component of this region’s avifauna, and several species, including the Red-legged Kittiwake, Least Auklet, and Whiskered Auklet, breed only in this region. Southern Hemisphere procellariiforms occur regularly in the offshore waters of the southern Bering Sea and northern Gulf of Alaska during Alaskan summers. The breeding diversity of passerines (mainly Lapland Longspur, Snow Bunting, and Gray-crowned Rosy-Finch), and shorebirds (including Black Oystercatcher, Dunlin, Ruddy Turnstone, and Rock Sandpiper) is low. However, McKay’s Bunting, the only endemic Alaskan passerine, is restricted to this area.
Bird Conservation Region 2 – Western Alaska
This region consists of the Subarctic Coastal Plain of western Alaska and the Alaska Peninsula Mountains. Wet and mesic graminoid herbaceous communities dominate the lowlands, and numerous ponds, lakes, and rivers dot the landscape. Tall shrub communities are found along rivers and streams, and low shrub communities occupy uplands. Forests of spruce and hardwoods penetrate the region on the eastern edge. Permafrost is continuous, except in southern parts of the region. High densities of breeding waterfowl and shorebirds are found on the coastal plain of the Yukon and Kuskokwim Rivers. Intertidal areas here and lagoons of the northern side of the Alaska Peninsula support millions of shorebirds during migration, including Dunlin, Western Sandpiper, Red Knot, and Bar-tailed Godwit. The coast of the Alaska Peninsula supports high concentrations of wintering sea ducks, including Steller’s Eider, Harlequin, Oldsquaw, Surf Scoter, and Black Scoter. Passerine diversity is greatest in tall, riparian shrub habitats, where Arctic Warbler, Gray-cheeked Thrush, and Blackpoll Warbler nest. Gyrfalcon and Rough-legged Hawk nest along the riverine cliffs. Mainland sea cliffs are occupied by nesting colonies of Black-legged Kittiwake, Common Murre, and Pelagic Cormorant.
Bird Conservation Region 3 – Arctic Plains and Mountains
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.
Bird Conservation Region 4 – Northwestern Interior Forest
The interplay of elevation, permafrost, surface water, fire, and aspect creates an extensive patchwork of ecological types. Forest habitat in the region is dominated by white spruce, black spruce, poplars, and paper birch. Tall shrub communities occur along rivers, drainages, and near treeline. Bogs, consisting of low shrubs and shrub-graminoid communities, are common in the lowlands. Alpine dwarf scrub communities are common throughout mountainous regions, and the highest elevations are generally devoid of vegetation. Lowlands, bottomlands, and flats harbor many species of migrating and breeding ducks (e.g., Northern Pintail, Northern Shoveler, Green-winged Teal) and swans. These and the forested lowlands and uplands support breeding shorebirds, such as Greater and Lesser Yellowlegs; Solitary, and Spotted Sandpipers; Sanderling; and Common Snipe. American Golden-Plovers and Surfbirds are found in alpine habitats in mountainous ecoregions. Western Sandpiper, Long-billed Dowitcher, Short-billed Dowitcher, Hudsonian Godwit, and Dunlin use stopover sites along the coast that are also primary wintering habitat for Rock Sandpipers. The suite of passerines inhabiting upland communities in the region includes Alder Flycatcher; Yellow-rumped Warbler; Dark-eyed Junco; Boreal Chickadee; Swainson’s and Gray-cheeked thrushes; American Pipit; White-crowned, American Tree, and Fox sparrows; and Common Redpoll. At high elevations, Horned Lark and American Pipit are common breeders.
Bird Conservation Region 5 – Northern Pacific Rainforest
The coastal rainforest stretches from the western Gulf of Alaska south through British Columbia and the Pacific Northwest to northern California. Its maritime climate is characterized by heavy precipitation and mild temperatures. The region is dominated by forests of western hemlock and Sitka spruce in the far north, with balsam fir, Douglas fir, and coast redwood becoming more important farther south. Broadleaf forests are found along large mainland river drainages. High priority breeding forest birds include the Spotted Owl, Marbled Murrelet, Northern Goshawk, Chestnutbacked Chickadee, Red-breasted Sapsucker, and Hermit Warbler. The coast of the Northern Pacific Rainforest is characterized by river deltas and pockets of estuarine and freshwater wetlands set within steep, rocky shorelines. These wetlands provide critical breeding, wintering, and migration habitat for internationally significant populations of waterfowl and other wetland-dependent species. The area includes major stopover sites for migrating shorebirds, especially Western Sandpipers and Dunlins. Black Oystercatchers, Rock Sandpipers, Black Turnstones, and Surfbirds arecommon wintering species. nearshore marine areas support many breeding and wintering sea ducks. Many seabirds breed on offshore islands, including important populations of Ancient Murrelet, Rhinoceros Auklet, Tufted Puffin, Common Murre, Western and Glaucous-winged Gull, and Leach’s Storm-Petrel. Pelagic waters provide habitat for large numbers of shearwaters, storm-petrels, alcids, and Black-footed Albatross.
Bird Conservation Region 6 – Boreal Taiga Plains
The Boreal Taiga Plains region is dominated by the Mackenzie River and its tributaries in its northern portion and the boreal transition zone in the south. Black spruce is a dominant species in the open, coniferous forests of the north, while the warmer betterdrained southerly locales support mixed-wood forests of white and black spruce, lodgepole pine, tamarack, white birch, trembling aspen, and balsam poplar. Low-lying wetlands cover 25–50 percent of the zone, and patterned ground features are common. A large portion of the area is underlain by permafrost, creating a landscape that is seasonally waterlogged over large areas. Important birds of the region include Whooping Crane, American White Pelican, Marsh Wren, Wilson’s Phalarope, Yellow-headed Blackbird, Sharp-tailed Grouse, Mountain Bluebird, Great Gray Owl, Swainson’s Hawk, and Fox Sparrow. The Mackenzie Valley forms one of North America’s most traveled migratory corridors for waterfowl breeding along the Arctic Coast.
Bird Conservation Region 7 – Taiga Shield and Hudson Plains
This BCR includes the Hudson Plains—the largest extensive area of wetlands in the world—and extends east and west onto the Canadian Shield. The subarctic climate is characterized by relatively short, cool summers with prolonged periods of daylight and long, very cold winters. The poorly drained areas of the Hudson Plains support dense sedge-moss-lichen covers, with open woodlands of black spruce and tamarack in better-drained sites. Coastal marshes and extensive tidal flats are present along the coastline. The Canadian Shield is characterized in upland sites and along rivers by open, mixed-wood forests of white spruce, balsam fir, trembling aspen, balsam poplar, and white birch. Further north, approaching the limit of tree growth, stunted black spruce and jack pine dominate, accompanied by alder, willow, and tamarack in the fens and bogs. Thousands of lakes and wetlands occur in glacially carved depressions, and peat-covered lowlands are commonly waterlogged or wet for prolonged periods due to discontinuous but widespread permafrost. The abundance of water provides an important habitat for breeding waterfowl. Representative birds include Black Scoter, Whimbrel, Rock and Willow Ptarmigan, Gray-cheeked Thrush, American Tree Sparrow, Short-billed Dowitcher, Common Redpoll, Harris’ Sparrow, Northern Shrike, Blackpoll Warbler, Fox Sparrow, and Rough-legged Hawk. The coasts of Hudson and James Bay provide critical shorebird staging habitat, funneling millions of birds southwards during fall migration.
Bird Conservation Region 8 – Boreal Softwood Shield
The Boreal Softwood Shield is a broad, U-shaped region comprised of seacoasts in the east and vast areas that are more than 80 percent forested by closed stands of conifers, largely white and black spruce, balsam fir, and tamarack. Toward the south, broadleaf trees, such as white birch, trembling aspen, and balsam poplar are more widely distributed, as are white, red, and jack pine. The region is a broadly rolling mosaic of uplands and associated wetlands, dotted with numerous small to medium-sized lakes. Peatlands are common in wetland areas. Representative birds include American Black Duck, Purple Sandpiper, Yellow Rail, Yellow-bellied Flycatcher, Black-backed Woodpecker, Boreal Owl, and Mourning, Palm, Bay-breasted, Connecticut, Cape May, Magnolia, and Tennessee Warblers. Coastlines and offshore areas in the east are important year-round for breeding and wintering seabirds.
Bird Conservation Region 9 – Great Basin
This large and complex region includes the Northern Basin and Range, Columbia Plateau, and the eastern slope of the Cascade Range. This area is dry due to its position in the rainshadow of the Cascade Range and the Sierra Nevada. Grasslands, sagebrush, and other xeric shrubs dominate the flats and lowlands, with piñon-juniper woodlands and open ponderosa pine forests on higher slopes. Lodgepole pine/sub-alpine fir forests occur at higher elevations on north-facing slopes. Several substantial lowland wetlands are extremely important to shorebirds, including breeding American Avocet; Black-necked Stilt; and Willet, migrating Wilson’s Phalarope, and other water birds, notably Eared Grebe. The region is also important for breeding Mountain Plover and Snowy Plover. Most of North American breeding White-faced Ibis and California Gulls nest in marshes and lakes scattered across the region. The Great Salt Lake and adjacent marshes host large numbers of American White Pelican, Cinnamon Teal, Northern Pintail, Redhead, Tundra Swan, and other waterfowl and many species of migrant shorebirds. Sage Grouse, Sage Sparrow, Sage Thrasher, and Brewer’s Sparrow are priority land birds of lowlands, with White-headed Woodpecker, Flammulated Owl, and Cassin’s Finch leading the list of characteristic birds of the region’s pine forests.
Bird Conservation Region 10 – Northern Rockies
Included in this area are the Northern Rocky Mountains and outlying ranges in both the United States and Canada, and also the intermontane Wyoming Basin and Fraser Basin. The Rockies are dominated by a variety of coniferous forest habitats. Drier areas are dominated by ponderosa pine, with Douglas fir and lodgepole pine at higher elevations and Engelman spruce and subalpine fir even higher. More mesic forests to the north and west are dominated by western larch, grand fir, western red cedar, and western hemlock. High priority forest birds include the Flammulated Owl, Lewis’ and Black-backed Woodpecker, Olive-sided Flycatcher, Townsend’s Warbler, Rufous Hummingbird, Black Swift, and Blue Grouse. Barrow’s Goldeneye, Harlequin Duck, and Trumpeter Swan breed in high-elevation lakes and streams. The Wyoming Basin and other lower-lying valleys are characterized by sagebrush shrubland and shrubsteppe habitat, much of which has been degraded by conversion to other uses or invasion of non-native plants. High priority birds include Sage Grouse, Ferruginous Hawk, Brewer’s Sparrow, and Sage Thrasher.
Bird Conservation Region 11 – Prairie Potholes
The Prairie Pothole region is a glaciated area of mixed-grass prairie in the west and tallgrass prairie in the east. This is the most important waterfowl production area on the North American continent, despite extensive wetland drainage and tillage of native grasslands. Breeding dabbling duck density may exceed 100 pairs per square mile in some areas during years with favorable wetland conditions. The region comprises the core of the breeding range of most dabbling duck and several diving duck species, as well as providing critical breeding and migration habitat for over 200 other bird species, including such priority species as Franklin’s Gull, Yellow Rail, and Piping Plover. Baird’s Sparrow, Sprague’s Pipit, Chestnut-collared Longspur, Wilson’s Phalarope, Marbled Godwit, and American Avocet are among the many priority non-waterfowl species breeding in this region. Wetland areas also provide key spring migration sites for Hudsonian Godwit, American Golden-Plover, White-rumped Sandpiper, and Buff-breasted Sandpiper. Continued wetland degradation and fragmentation of remaining grasslands threaten future suitability of the Prairie Pothole region for all of these birds.
Bird Conservation Region 12 – Boreal Hardwood Transition
This region is characterized by coniferous and northern hardwood forests, nutrient-poor soils, and numerous clear lakes, bogs, and river flowage. All of the world’s Kirtland’s Warblers breed here, as do the majority of Golden-winged Warblers and Connecticut Warblers. Other important forest birds include the Black-billed Cuckoo, Veery, and Rose-breasted Grosbeak. Great Lakes coastal estuaries, river flowage, large shallow lakes, and natural wild rice lakes are used by many breeding and migrating water birds. Yellow Rail are among the important wetland species, and islands in the Great Lakes support large colonies of Caspian and Common Terns. Although breeding ducks are sparsely distributed, stable water conditions allow for consistent reproductive success. Wood Duck, Mallard, American Black Duck, Ring-necked Duck, and Common Goldeneye are common breeding species in this region. Threats to wetland habitat in this region include recreational development, cranberry operations, peat harvesting, and drainage.
Bird Conservation Region 13 – Lower Great Lakes/St. Lawrence Plain
The Lower Great Lakes/St. Lawrence Plain covers the low-lying areas to the south of the Canadian Shield and north of various highland systems in the United States. In addition to important lakeshore habitats and associated wetlands, this region was originally covered with a mixture of oak-hickory, northern hardwood, and mixed-coniferous forests. Very little of the forests remains today due primarily to agricultural conversion. The highest priority bird in remnant forests is the Cerulean Warbler. Because of agriculture, this is now the largest and most important area of grassland in the Northeast, providing habitat for such species as Henslow’s Sparrow and Bobolink. Agricultural abandonment may temporarily favor shrub-nesting species, such as Golden-winged Warbler and American Woodcock, but increasingly, agricultural land is being lost to urbanization. This physiographic area also is extremely important to stopover migrants, attracting some of the largest concentrations of migrant passerines, hawks, shorebirds, and waterbirds in eastern North America. Much of these concentrations occurs along threatened lakeshore habitats.
Bird Conservation Region 14 – Atlantic Northern Forest
The nutrient-poor soils of northernmost New England and the Adirondack Mountains support spruce-fir forests on more northerly and higher sites and northern hardwoods elsewhere. Virtually all of the world’s Bicknell’s Thrush breed on mountaintops in this region. Other important forest birds include the Canada Warbler and Bay-breasted Warbler. Coastal wetlands are inhabited by Nelson’s Sharp-tailed Sparrow; rocky intertidal areas are important for wintering Purple Sandpipers; and muddy intertidal habitats are critical as Semipalmated Sandpiper staging sites. Common Eiders and Black Guillemots breed in coastal habitats, while Leach’s Storm-Petrels, gulls, terns, and the southernmost populations of many breeding alcids nest on offshore islands. Beaver ponds and shores of undisturbed lakes and ponds provide excellent waterfowl breeding habitat, particularly for American Black Duck, Hooded and Common Mergansers, and Common Goldeneye. The Hudson and Connecticut River valleys are important corridors for Brant, Green-winged Teal, and other waterfowl migrating from New England and Quebec. Because inland wetlands freeze, coastal wetlands are used extensively by dabbling ducks, sea ducks, and geese during winter and migration.
Bird Conservation Region 15 – Sierra Nevada
The Sierra Nevada range rises sharply from the Great Basin on the east and slopes gently toward the Central Valley of California on the west. Vegetation at lower elevations is dominated by ponderosa pine on the west and lodgepole pine on the east, with fir, spruce, and alpine tundra at higher elevations. The area provides habitat for Hermit Warbler, White-headed Woodpecker, and Mountain Quail at higher elevations and Nuttall’s Woodpecker, Oak Titmouse, and California Thrasher on the western slopes.
Bird Conservation Region 16 – Southern Rockies/Colorado Plateau
This topographically complex region includes the Wasatch and Uinta Mountains to the west and the Southern Rocky Mountains to the east, separated by the rugged tableland of the Colorado Plateau. Various coniferous forest types (often lodgepole pine) interspersed with aspen dominate higher elevations. These are replaced by piñon-juniper woodlands on the lower plateaus. Important birds also segregate into elevational bands, with Brown-capped Rosy-Finch and White-tailed Ptarmigan in alpine tundra, Williamson’s Sapsucker in conifers, Virginia’s Warbler and Lewis’ Woodpecker in montane shrub sites, and most of the world’s breeding Gray Vireos in piñon-juniper. High arid plains and dry upland short-grass prairies provide critical breeding areas for Mountain Plover. San Luis Valley wetlands and surrounding uplands support one of the highest densities of nesting waterfowl in North America and provide migration habitat for Sandhill Cranes and other wetland species.
Bird Conservation Region 17 – Badlands and Prairies
This semi-arid rolling plain is dominated by a mixed-grass prairie that lies west and south of the glaciated Prairie Pothole region, east of the Rocky Mountains, and north of the true shortgrass prairie. Due in large part to the continued dominance of ranching as a land use, many contiguous grassland tracts of significant size persist in this area. As a result, this area is habitat for some of the healthiest populations of high priority dry-grassland birds on the continent, including Mountain Plover, McCown’s Longspur, and Long-billed Curlew. The relatively small number of wetlands in the region, including small impoundments created to serve as livestock water sources, receives intensive use by upland nesting waterfowl and broods.
Bird Conservation Region 18 – Shortgrass Prairie
The shortgrass prairie lies in the rainshadow of the Rocky Mountains, where arid conditions greatly limit the stature and diversity of vegetation. Some of the continent’s highest priority birds breed in this area, including the Mountain Plover, Long-billed Curlew, Burrowing Owl, Lark Bunting, Grasshopper Sparrow and McCown’s Longspur. Southern areas winter large numbers of three longspur species: McCown’s, Lapland and Chestnut-collared. Reasons for the precarious status of some these birds are poorly understood, but could involve a reduction in the diversity of grazing pressure as bison and prairie dogs have largely been replaced by cattle, and the gradual shift from once expansive prairies to fragmentation by agricultural interests. The BCR, along with BCR 19, hosts an endemic shrub community known as shinnery which in southern portions of the BCR hosts one of the species with the highest threats – the Lesser Prairie-Chicken. A few large rivers, such as the Platte, Arkansas and Canadian,drain out of the Rocky Mountains through this region toward the Mississippi. These rivers created broad, braided and treeless wetlands that are heavily used by migrating waterfowl, shorebirds and cranes. A hydrological simplification has resulted in the invasion of trees and shrubs that support breeding eastern riparian birds, but otherwise greatly reduce the value of the area’s wetlands. Playa lakes, the most numerous wetlands in the BCR, are shallow, ephemeral wetlands that, when wet, support many wintering ducks including Northern Pintail, migrant shorebirdsincluding Baird’s and Least Sandpiper, and migrant Black Tern and Franklin’s Gull among other waterbirds. Saline lakes in Texas and New Mexico support important breeding species, such as the Snowy Plover and wintering populations of Sandhill Cranes. For further information on this region, visit the Playa Lakes Joint Venture website.
Bird Conservation Region 19 – Central Mixed-grass Prairie
The central mixed-grass prairie extends from the edge of shortgrass prairie on the west to the beginning of the tallgrass prairie and savanna-like habitat to the east. Large areas in the center of this region have been converted to agriculture, though extensive areas of high-quality grassland in the Nebraska Sandhills and excellent shrublands in Texas remain. The BCR includes some of the best habitat for priority species such as Greater Prairie-Chicken, Scissor-tailed Flycatcher and Grasshopper Sparrow.Dickcissel abundance is centered squarely over this BCR. In winter this BCR hosts large numbers of Harris’s Sparrow. Sandbars along the larger rivers host a large percentage of the continent’s breeding Interior Least Terns. Riparian woodland areas host Red-headed Woodpeckers and the continent’s highest Mississippi Kite population. The region is a continentally important migration area for shorebirds and is home to three recognized Western Hemisphere Shorebird Reserve Network sites for priority shorebirds, including American Avocet, Semipalmated Sandpiper and Buff-breasted Sandpiper.An estimated 90 percent of all the world’s White-rumped Sandpipers migrate through central Kansas in the spring. Between 10 and 14 million waterfowl migrate through Nebraska and utilize the staging habitat in the seasonal, depressional rainwater basins and other wetlands. The mid-continent population of Northern Pintail and White-fronted Goose are particularly dependent on these wetland resources. However, wetland drainage, modification and sediment accumulation have jeopardized the integrity of these important landscape features. Conservation efforts of these resources center on the conversion of agricultural lands back to healthy grasslands and wetlands. For further information on this region, visit the Playa Lakes Joint Venture website or the Rainwater Basin Joint Venture website.
Bird Conservation Region 20 – Edwards Plateau
This dissected Hill Country of central Texas is clearly demarcated on the east and south by a fault line and grades into the Chihuahuan Desert and Great Plains to the west and north. The native vegetation is a mesquite, juniper, and oak savanna that is the core of the breeding range of the endangered Black-capped Vireo and Golden-cheeked Warbler. Other priority breeding birds include the Scissor-tailed Flycatcher and Bell’s Vireo. Intensive grazing by goats has caused vegetation to shift from grass to thicket dominance. Suburban expansion is a more recent threat to bird habitat in the Edwards Plateau.
Bird Conservation Region 21 – Oaks and Prairies
This transition zone between the Great Plains and the forests of the eastern United States is a complex mix of prairie, savanna, cross timbers, and shrubland. Among the priority landbirds that use this mix of woodland and open country are the Scissor-tailed Flycatcher, Painted Bunting, and Mississippi Kite, with a small population of Black-capped Vireos in areas of denser shrub. Agriculture and urbanization have made tremendous impacts on this region, leaving very little natural habitat available for healthy priority bird populations.
Bird Conservation Region 22 – Eastern Tallgrass Prairie
This region includes what was formerly the tallest and lushest grasslands of the Great Plains. Beech-maple forest dominated in the eastern sections, and the prairie and woodland ecotone between the two was marked by a broad and dynamic oak-dominated savanna. The modern landscape of the Eastern Tallgrass Prairie is dominated by agriculture. Threats to the upland and wetland habitats of this region include urbanization, recreational development, and agricultural expansion. High priority grassland birds that persist in some areas include the Greater Prairie-Chicken and Henslow’s Sparrow. Cerulean Warblers are in some wooded areas, and Red-headed Woodpecker leads the list of savanna specialists.
Bird Conservation Region 23 – Prairie Hardwood Transition
Prairies once dominated this region in the west and south and beech-maple forest in the north and east, separated by an oak savanna. There are still remnant populations of Greater Prairie-Chicken in grasslands and Cerulean Warbler and other forestbreeding migrants to the northeast. Early successional habitat is used by Golden-winged Warblers, Henslow’s Sparrows, and American Woodcock. Glaciation has resulted in numerous pothole-type wetlands and shallow lakes, and the Great Lakes’ coastal estuaries are the destinations of many rivers. Additional important waterfowl lakeshore-wetland habitats range from emergent marshes and diked impoundments to normally ice-free deepwater habitats valuable for diving ducks. This region is second only to the Prairie Pothole region in terms of support of high densities of breeding waterfowl, including Mallard, Blue-winged Teal, Wood Duck, and Redhead.
Bird Conservation Region 24 – Central Hardwoods
The Ozark Mountains on the west and Interior Low Plateaus on the east are geologically similar to each other but are bisected by the floodplain of the Mississippi River and its larger tributaries. The entire area is dominated by an oak-hickory deciduous forest inhabited by interior forest species, such as Cerulean Warbler, Worm-eating Warbler, and Louisiana Waterthrush. The region includes some of the most extensive forests in the middle of the continent and is probably a source for populations of these birds for many surrounding areas. Among early succession birds, this is the last major stronghold of the Eastern Bewick’s Wren. Restoration of prairie, glade, and barren habitat is a conservation priority. Although Wood Ducks are the primary breeding waterfowl, the region holds more significance for waterfowl as a migratory staging area. The floodplains of the river systems exhibit a diversity of habitats (e.g., floodplain forests, emergent wetlands, and submerged aquatic beds), all of which are utilized by migrating waterfowl. Large concentrations of waterfowl, including Mallard, Lesser Scaup, and Canvasback, are common during both spring and fall migration. Threats to the habitats of the region include agricultural conversion of floodplain habitats and urbanization.
West Gulf Coastal Plain/Ouachitas
Pines dominate this area, largely shortleaf pine in the north, including the Ouachita Mountains, and longleaf pine in the south. This westernmost part of the eastern United States forest also includes hardwood-dominated bottomlands along the Arkansas River and other drainages. Red-cockaded Woodpecker is the highest priority bird in pine habitat, which is also inhabited by Bachman’s Sparrow and Brown-headed Nuthatch. Conversion of the native pine forests to industrial loblolly plantations provides some bird habitat but is less useful for the highest priority species. The river and stream bottoms provide habitat used by Swainson’s Warbler and large numbers of nesting herons and egrets. Bottomland hardwoods and associated wetlands support substantial wintering populations of a number of waterfowl species—principally Mallards, and breeding and wintering Wood Ducks—and are a primary migration corridor for significant numbers of other dabbling ducks. The primary threats to bottomland hardwood wetlands in the region are from reservoirs and timber harvest and subsequent conversion to pine plantation, pasture, or other land uses.
Bird Conservation Region 26 – Mississippi Alluvial Valley
The Lower Mississippi Alluvial Valley consists of approximately 24 million acres of alluvial floodplain south of the Mississippi River’s confluence with the Ohio River. Prior to European settlement, this was the greatest bottomland hardwood forest on earth and was subject to massive annual flood events of the Mississippi River and its tributaries. These forested wetlands were the main wintering area for mid-continent Mallards, Wood Ducks, and other waterfowl species. Flood control and deforestation for agriculture began more than 100 years ago. Today, less than 25 percent of the region remains forested, and flooding has been reduced by about 90 percent. Despite these changes, the region still winters large numbers of waterfowl, estimated at about 9 percent of the continental duck population. With the large reduction in native habitat and natural flooding, the major waterfowl management issue today is providing enough foraging habitat on managed private and public lands to reliably meet the needs of wintering ducks and geese. Many shorebird species also use managed wetlands for migration stopover sites. Remnant forests harbor populations of Swainson’s Warbler, prothonotary Warbler, and Swallow-tailed Kite. The region provides excellent colonial waterbird habitat, particularly to the south where large numbers of White Ibis, Yellow-crowned Night-Heron, and other herons and egrets nest.
Bird Conservation Region 27 – Southeastern Coastal Plain
This region includes extensive riverine swamps and marsh complexes along the Atlantic Coast. Interior forest vegetation is dominated by longleaf, slash, and loblolly pine forests. Priority landbirds include the Red-cockaded Woodpecker, Painted Bunting, Bachman’s Sparrow, Swainson’s Warbler, and Swallow-Tailed Kite. Coastal intertidal habitats provide critical wintering areas for American Oystercatcher, important wintering and spring migration areas for Short-billed Dowitcher and Dunlin, and important fall staging areas for Red Knot. Sizable numbers of Brown Pelicans and various terns breed on offshore islands. Coastal areas provide important nesting and foraging habitats for large numbers of herons, egrets, ibis, terns, and other species. Coastal areas winter large numbers of Canvasback, Mallard, American Wigeon, Redhead, and the majority of the continent’s population of Tundra Swans. Managed impoundments in coastal areas are important to migrating and wintering dabbling ducks, including American Black Duck.
Bird Conservation Region 28 – Appalachian Mountains
Included in this area are the Blue Ridge, the Ridge and Valley Region, the Cumberland Plateau, the Ohio Hills, and the Allegheny Plateau. The rugged terrain is generally dominated by oak-hickory and other deciduous forest types at lower elevations and by various combinations of pine, hemlock, spruce, and fir in higher areas. While flatter portions are in agricultural use, the majority of most segments of this region are forested. Priority forest birds include Cerulean Warbler at low elevations and Blackthroated Blue Warbler at high elevations. Golden-winged Warblers are in early successional areas, and Henslow’s Sparrows are in grasslands. While not as important for waterfowl as coastal regions, the Appalachian region contains the headwaters of several major eastern river systems that are used by various waterfowl species during migration. In addition, large wetland complexes, such as Canaan Valley in West Virginia, and isolated beaver-created wetlands provide habitat for Wood Duck breeding.
Bird Conservation Region 29 – Piedmont
The Piedmont is transitional between the mountainous Appalachians and the flat coastal plain and is dominated by pine and mixed southern hardwoods. Priority landbirds include Redcockaded Woodpecker, Bachman’s Sparrow, and Brown-headed Nuthatch. Interior wetlands, reservoirs, and riverine systems provide migration and wintering habitat for waterfowl and some shorebirds. The fragmented patchwork of pasture, woodlots, and suburban sprawl that now dominates most of this region creates significant bird conservation challenges.
New England/Mid-Atlantic Coast
This area has the densest human population of any region in the country. Much of what was formerly cleared for agriculture is now either in forest or in residential use. The highest priority birds are in coastal wetland and beach habitats, including the Saltmarsh Sharp-tailed Sparrow and Nelson’s Sharp-tailed Sparrow, Seaside Sparrow, Piping Plover, American Oystercatcher, American Black Duck, and Black Rail. The region includes critical migration sites for Red Knot, Ruddy Turnstone, Sanderling, Semipalmated Sandpiper, and Dunlin. Most of the continental population of the endangered Roseate Tern nests on islands off the southern New England states. Other terns and gulls nest in large numbers, and large mixed colonies of herons, egrets, and ibis may form on islands in the Delaware and Chesapeake Bay regions. Estuarine complexes and embayments created behind barrier beaches in this region are extremely important to wintering and migrating waterfowl, including approximately 65 percent of the total wintering American Black Duck population, along with large numbers of Greater Scaup, Tundra Swan, Gadwall, Brant, and Canvasback. Exploitation and pollution of Chesapeake Bay and other coastal zones, and the accompanying loss of submerged aquatic vegetation, have significantly reduced their value to waterfowl.
Bird Conservation Region 31 – Peninsular Florida
The northern portion of Peninsular Florida is a transitional zone where the pine and bottomland hardwood elements of the Coastal Plain begin to merge with the tropical elements of south Florida. Many of the important pine and bottomland birds of the Coastal Plain, including Red-cockaded Woodpecker and Swallow-tailed Kite, extend into this area. The central scrub-oak Lake Wales Ridge is a center of endemism that includes all of the world’s Florida Scrub-Jays. Colonies of Wood Stork, Glossy Ibis, and19 other herons and egrets are found throughout the region, while coastal islands support important continental breeding populations of Brown Pelicans, Black Skimmers, and various terns. Farther south, in the subtropical zone of the state, a normally frost-free climate creates conditions for mangroves, everglades, and tropical hammocks, tying this area more closely to the Bahamas and Caribbean than to the rest of the United States. Snail Kite, Shorttailed Hawk, and Limpkin breed in interior wetlands, with Mangrove Cuckoo and Black-whiskered Vireo in coastal mangroves. One of the greatest wading-bird concentrations in the world is in the Everglades. White-crowned Pigeons inhabit the Florida Keys, and the only Brown Noddy, Sooty Tern, and Magnificent Frigatebird breeding site in the country is on the Dry Tortugas. Wintering waterfowl abound in coastal waters, including large numbers of Lesser Scaup, Ring-necked Duck, and Green-winged Teal. The endemic Florida subspecies of Mottled Duck, Wood Duck, and Fulvous Whistling-Duck also breed in the area. Most of the remaining nesting Snowy Plovers in the Southeast occur along Florida’s Gulf Coast. Extraordinary numbers of wintering and intransit shorebirds also use the region, particularly Short-billed Dowitchers, but also Piping Plover, Dunlin, and Red Knot.
Bird Conservation Region32 – Coastal California
A Mediterranean climate of hot, dry summers and cool, moist winters creates conditions for mixed chaparral vegetation in the low mountains along the coast that extends into Baja California. These habitats support such birds as California Gnatcatcher, California Quail, Mountain Quail, Pygmy Nuthatch, Wrentit, California Thrasher, Nuttall’s Woodpecker, Oak Titmouse, and Lawrence’s Goldfinch. The coastline provides habitat for several waterfowl and shorebird species and is an important wintering area for Marbled Godwit, American Avocet, and Surfbird. Most of the world’s populations of Ashy Storm-Petrel and Xantus’ Murrelet nest on a small number of offshore islands. A sizable proportion of the Elegant Tern and Heermann’s Gull populations spend the non-breeding season here. Millions of Sooty Shearwaters gather in pelagic waters each fall, joined by numbers of other shearwaters, storm-petrels, and alcids. The Central Valley of California lies in this region between the coastal ranges and the Sierra Nevada. Wetlands and associated uplands in the Central Valley provide roosting and foraging habitat for 60 percent of the waterfowl that winter in the Pacific Flyway, including a majority of the continental Northern Pintail population. Approximately 95 percent of the Central Valley’s depressional wetlands and 84 percent of riparian habitat have been lost, primarily to agriculture. A good deal of the remaining wetland habitat is protected within national wildlife efuges, but the majority is privately managed for waterfowl hunting. Among landbirds, the Central Valley is the center of the small ranges of the Tricolored Blackbird and Yellowbilled Magpie and also provides dwindling habitat for a host of riparian birds, such as Least Bell’s Vireo.
Bird Conservation Region 33 – Sonoran and Mohave Deserts
The Mohave Desert covers southeastern California and southern Nevada and adjoins the Sonoran Desert, which extends from southwestern Arizona south on both sides of the Gulf of California into the Mexican states of Baja California, Sonora, and Sinaloa. This rid region is dominated by cacti, slow-growing grasses, creosote, and other desert shrubs. The Colorado River and adjacent wetlands provide habitat for ducks and other wetland birds, including some of the most important habitat in the arid southwest for Western and Clark’s Grebes and American Avocets. This region also includes El Pinacate y Gran Desierto de Altar Biosphere Reserve in northern Mexico, which is a unique biome providing habitat for many raptors, such as Golden Eagle and wintering Northern Harrier, Shorteared Owl, and Merlin. Isla Tiburón, located off the coast of Sonora in the Gulf of California, is an IBA that harbors endemic forms of the Northern Flicker, Cactus Wren, and Xantus’ Hummingbird and such pelagic birds as the Magnificent Frigatebird, Red-billed Tropicbird, Brown Booby, Blue-footed Booby, and Craveri’s Murrelet. Another Mexican IBA, the Sistema Tóbari, supports large numbers of American Avocet, Marbled Godwit, Northern Pintail, and Lesser Scaup. This BCR is the center of distribution of the Rufous-winged Sparrow, LeConte’s Trasher, Lucy’s Warbler, and Abert’s Towhee. Riparian wetlands are habitat for the Yuma Clapper Rail and Southwestern Willow Flycatcher. The Salton Sea hosts large numbers of American White Pelicans, Eared Grebes, and other colonial waterbirds; shorebirds, such as the Black-necked Stilt and Long-billed Curlew; and waterfowl during both migration and winter.
Bird Conservation Region 34 – Sierra Madre Occidental
The Sierra Madre Occidental mountain range runs northwest to southeast parallel to the Pacific Coast from the Mogollon Rim and isolated mountain ranges in southeastern Arizona and southwestern New Mexico through Sonora to central Mexico, where it connects with the Sur del Altiplano Mexicano. It is characterized by high elevations and a complex topography with the presence of oak-pine, pine, and fir forests along the mountain range and of semiarid scrub habitats on eastern slopes. In Mexico there are more than 20 IBAs in this BCR, including El Carricito, a remnant of old-growth pine-oak forest and habitat for the presumably extinct Imperial Woodpecker and other important species, such as Golden Eagle, Military Macaw, Thick-billed Parrot, and Eared Trogon. Other priority landbirds of this BCR in Mexico are the Rose-throated Becard, Spotted Owl, Golden Eagle, and Peregrine Falcon. Among the species whose range extends into the United States in this region, highest priorities include the Red-faced Warbler, Strickland’s Woodpecker, and Montezuma Quail. Riparian areas in lowlands support many in-transit migrants as well as breeding Thick-billed Kingbirds, Western Yellow-billed Cuckoos, and Southwestern Willow Flycatcher. Most uplands in the United States are publicly owned, but lower-elevation grasslands and riparian habitat are subject to development and conversion. The whole region is an important corridor for migration of many species in the west. Significant wetland habitats, such as Santiaguillo Lagoon in Durango, Mexico, provide wintering habitat for large numbers of aquatic birds, highlighted by Northern Pintails and American White Pelicans.
Bird Conservation Region 35 – Chihuahuan Desert
The Chihuahuan Desert stretches from the Sierra Madre Occidental in the west to lusher scrub habitat of the Edwards Plateau and Tamaulipan Brushlands in the east, and from the Southern Great Plains to the north and over much of the central Mexican Plateau. Arid grasslands and shrublands cover broad basins, and higherelevation oak-juniper woodlands and conifers occur in numerous isolated mesas and mountains. In Mexico, IBAs include Janos–Nuevo Casas Grandes, home of the Burrowing Owl, Golden and Bald Eagles, Peregine and Prairie Falcons, Lucy’s Warbler, and Mountain Plover. Sierra del Nido, with Eared Trogon, Thick-billed Parrot, and Lucifer’s Hummingbird, and Mapimí are two other key IBAs. Other important typical species are Scaled Quail in the lowlands, Bell’s Vireo along some riparian zones, and Black-capped Vireo in the montane scrub community. The Colima Warbler is a rare inhabitant of a few of the higher mountains. The Río Grande and adjacent wetlands provide important habitat for Sandhill Cranes, waterfowl, and other riparian and wetland-dependent birds.
Bird Conservation Region 36 – Tamaulipan Brushlands
This plain extends from southern Texas into northeastern Mexico. Much of the grassland, savanna, and thornscrub habitat has been converted to more shrubby conditions as a result of grazing history. Important Bird Areas in Mexico include Presa Venustiano Carranza, with nesting habitat for Mexican Ducks and Golden Eagles. It is also a key site for migrating Greater White-fronted Geese, Sandhill Cranes, and many species of ducks. Parras de la Fuente is an IBA that supports an important nesting colony of White-winged Dove and provides habitat for Red-crowned Parrot and Yellow-headed Parrot. Other distinctive avifauna of this region includes Audubon’s Oriole, Buff-bellied Hummingbird, Long-billed Thrasher, and Plain Chachalaca. Botteri’s Sparrow, Attwater’s Prairie-Chicken, Whitetailed Hawk, wintering Whooping Crane, and LeConte’s Sparrow are high priority species of grassland habitats. Wetlands are habitat for Black-bellied Whistling-Ducks and a great variety of wading and shorebirds, as well as for several wintering waterfowl species.
Bird Conservation Region 37 – Gulf Coastal Prairie
Flat grasslands and marshes hug the coast of the Gulf of Mexico from northern Tamaulipas across the mouth of the Río Grande up into the rice country of southeastern Texas and southwestern Louisiana and across the great Louisiana marshlands at the mouth of the Mississippi River. The Laguna Madre on both sides of the border (an IBA in Mexico) is dominated by dunes, beaches, and black mangroves. This BCR features one of the greatest concentrations of colonial waterbirds in the world, with breeding Reddish Egret, Roseate Spoonbill, Brown Pelican, and large numbers of herons, egrets, ibis, terns, and skimmers. The region provides critical in-transit habitat for migrating shorebirds, including Buffbreasted Sandpiper and Hudsonian Godwit, and for most of the neotropical migrant forest birds of eastern North America. Mottled Duck, Fulvous Whistling-Duck, and Purple Gallinule also breed in wetlands, and winter numbers of waterfowl are among the highest on the continent. These include dabbling ducks (especially Northern Pintail and Gadwall), Redhead, Lesser Scaup, and White-fronted Geese from both the Central and the Mississippi Flyways. The most important waterfowl habitats of the area are coastal marsh, shallow estuarine bays and lagoons, and wetlands on agricultural lands of the rice prairies. Loss and degradation of wetland habitats due to subsidence, sea-level rise, shoreline erosion, freshwater and sediment deprivation, saltwater intrusion, oil and gas canals,and navigation channels and associated maintenance dredging are the most important problems facing the area’s wetland wildlife.