The accompanying maps show the distribution of habitats of the most conspicuous species in the three subregions. Depicted on these maps are the habitats of black bears, brown-grizzly bears, caribou, moose, Sitka black-tailed deer, Dall sheep, mountain goats, bison.

The distribution of these and a few other representative species is presented in the subregional descriptions. The species mentioned should be considered as merely illustrative of the distribution of the thousands of other species that occupy the same habitats. The Dall sheep, for instance, shares its alpine ranges with many other animals, including single-celled protozoa in the soil; nematodes, both free-living and parasitic; mites; spiders; insects; pikas; hoary marmots; golden eagles; and wandering tattlers, to name a few.

The relationship of animal species to specific habitat types may be very binding, as in the case of the muskrat which requires a marshy habitat, or the pika which is found only in rocky alpine areas. It may also be quite loose, as in the case of the wolverine or the raven, either of which may be found as commonly at the edge of a lowland marsh as on a rugged mountain slope.

There is little clear-cut differentiation between an aquatic habitat and its surrounding uplands. In general, the animal population of these uplands is influenced strongly by the presence of the water area. For example, the use of a birch stand by beaver or the nesting of a pair of swans in tundra depends on the presence of a nearby water area. Many other mammal and bird species are affected similarly. Migrating birds, for example, whether upland or aquatic species, often follow migration routes along coasts or stream valleys and at that time may be considered aquatic.

In general, the more stringent the requirements of a species for a certain habitat, the more critical the habitat is to the welfare of the species. The bald eagle in the Southcentral Region, for example, nests almost universally in tall trees near salt water, and the availability of an adequate number of nesting trees is critical to this species for its reproduction. Other species may have different specific habitat requirements. Parts of the Southcentral Region, such as the Anchorage area, have an abundance of summer range for moose but a shortage of winter range. In this case the availability of winter range is critical to the species.

Some of the relationships of animals to habitat types are seasonal. For example, many of the moose in the Region occupy subalpine ranges in summer and autumn but move to lowland areas during the heavy winter snows. Other animals, such as the spruce grouse, may not move their residence with the seasons, but may move from the ground, where they live during snow-free seasons, to spruce trees in winter. More pronounced are the seasonal movements of migrating birds and caribou.

Habitats of the Southcentral Region are particularly important in their function as routes for migrating birds, many of which nest beyond the Arctic Circle and winter as far south as California and Mexico. The narrow coastal fringe between the Gulf of Alaska and the Chugach and St. Elias Mountains is the gateway to Alaska for most of the birds which winter in the Pacific Flyway.

King and Lensink (1971) emphasized the importance of the Copper River delta to migrating waterfowl and pointed out that other birds also depend on the same habitat. An abundance of birds uses the coastal wetlands of the Copper River delta at various seasons. Birds migrate up the narrow band of vegetative habitat along the coast, many resting for a period on the delta. Some proceed up the Copper River to Interior and Arctic nesting grounds. Others migrate westward, some to western Prince William Sound and through Portage Pass to Cook Inlet, then north up the Susitna Valley or westward through the Alaska Range. Others continue westward from eastern Prince William Sound to western Alaska and the Aleutians.

Black bear: Black bears are absent from the Kodiak Island group and are rarely found on the Alaska Peninsula south of Lake Iliamna.

Brown-grizzly bear: These bears inhabit all of the major islands and the Alaska Peninsula .

Population estimates range up to 2,000 bears on Kodiak Island and 2,500 to 3,000 on the entire island group. Densities on the Alaska Peninsula are probably similar. Brown bears are usually found on salmon streams during the runs where they feed heavily on the migrating fish. This food resource, which is very important in the bears' diet, has led to conflicts with fishermen. Bear populations on Kodiak also occur in proximity to cattle ranches, and more or less continuous conflict occurs between bears and ranchers in spite of efforts to find solutions.

Sitka black-tailed deer: Twenty-five deer from Southeastern Alaska were successfully transplanted to the Kodiak Island group between 1923 and 1934 .

The size of the present population is unknown, but the annual take has exceeded 2,000 animals in some recent years. The population still appears to be increasing. No Sitka black-tailed deer live on the Alaska Peninsula.

Dall sheep: Sixteen sheep were transplanted to Kodiak Island between 1964 and 1967. Half of them died within two weeks, and there have been no authenticated sightings since 1968. None are found on the Alaska Peninsula.

Roosevelt elk: Elk occur in Alaska only on Afognak and Raspberry Islands. Three male and five female calves were transplanted to Afognak Island from the state of Washington in 1928. There are now about 500 animals on the two islands, but there may have been 1,500 or more in 1965.

Mountain goat: Eighteen animals were transplanted to Kodiak Island in 1952-1953 (Figure 136a). The present population is at least 91, and they are thriving. No goats are found on the Alaska Peninsula.

Wolf: Wolves occur on the Alaska Peninsula in modest numbers but are not present on the Kodiak Island group.

Wolverine: Wolverines, though nowhere abundant, occur throughout the Peninsula. There are none on the Kodiak Island group.

Barren ground caribou: Caribou are found on the entire Alaska Peninsula but use the north side much more than they do the Pacific side (Figure 135a). The herd numbers about 15,000. Although there are no caribou on the Kodiak Island group, there are feral reindeer on Kodiak Island.

Although limited, waterfowl breeding habitat in the subregion is important for a variety of species. Pacific eiders, which are widely scattered throughout the area, nest on rocky shores and islets. The mountainous coasts provide important wintering habitat for scoters, eiders, oldsquaws, mallards, harlequin ducks, black brant, the entire population of emperor geese, and a tiny group of whooper swans. There is a major migration route through Shelikof Strait and along the Alaska Peninsula. Other waterfowl found in the area where suitable habitat exists include common, Arctic, and red-throated loons; Canada geese; pintails; green-winged teal; widgeons; greater scaup; common and Barrow's goldeneye; buffleheads; a few gadwalls; some shovelers; common and red-breasted mergansers; a few canvasbacks; and red-necked and horned grebes. Figure 137a delineates important waterfowl habitats.

The rocky shores, which characterize the seacoasts of this subregion, are excellent habitat for bald eagles and peregrine falcons. Eagles often nest near salmon streams, usually in large trees in old-growth timber along the saltwater shoreline and larger, mainland rivers. Other predatory birds which probably occur in the subregion are sharp-shinned hawks; goshawks; marsh hawks; gyrfalcons; golden eagles; ospreys; pigeon hawks; and snowy, great horned, great grey, hawk, boreal, saw whet, and short-eared owls.

This subregion contains approximately 50 major seabird colonies. At least one of these accommodates more than 1,000,000 birds, and several others contain more than 100,000 each (Figure 137a).These colonies include glaucous, glaucous-winged, herring, Thayer's, Bonaparte's, mew, and Sabine's gulls; black-legged kittiwakes; Aleutian and Arctic terns; horned and tufted puffins; common and thick-billed murres; Cassin's, parakeet, crested, and least auklets; Pacific fulmar; double-crested, pelagic and red-faced cormorants; marbled, Kittlitz's and ancient murrelets; pigeon guillemots; and probably forktailed and Leach's petrels. Pomarine, parasitic, and occasionally long-tailed jaegers inhabit this subregion and prey upon the smaller passerine birds and smaller gulls and terns.

The limited amount of marsh and lowland in the area is inhabited by many species of shorebirds.

Passerine (perching) birds are found throughout this subregion. Kingfishers, ravens, magpies, northwestern crows, swallows, thrushes, winter wrens, robins, several species of sparrow, several species of warblers, kinglets, water pipits, dippers, grosbeaks, finches, common redpolls, crossbills, several woodpeckers, and others can be seen in the proper habitat.

The peregrine falcon in this subregion, Peale's peregrine, Falco peregrinus pealei, is not endangered.

Black bear: Some of Alaska's densest black bear populations occur in this subregion, particularly on the Kenai Peninsula, the Susitna Valley, and in mountains between Turnagain and Knik Arms . The density is lower in the interior regions.

Brown-grizzly bear: This bear is common throughout the subregion with lowest numbers in the Anchorage area and western Kenai Peninsula (Figure 135b). Most bears are killed incidentally to hunting of other game.

Wolf: Wolves of the subregion are most common in the interior and Susitna drainages. They are rare in the Anchorage area, although present in the Chugach Mountains to the east. Apparently, the wolf disappeared from the Kenai Peninsula but has now returned. Probably only 20-60 animals are present on the Peninsula.

Wolverine: These animals are common throughout the subregion except in areas of high human population. They are most abundant in the interior portions of the subregion.

Barren ground caribou: Several herds use portions of the subregion; the Nelchina herd in the northeast section, the McKinley herd in the northcentral section, and the Kenai herd on the Kenai Peninsula (Figure 135b). The most important of these is the Nelchina herd, one of the most significant large mammal populations of the Southcentral Region. The entire area of potential use by the Nelchina herd encompasses about 75,000 square miles, but only 20,000 square miles are used at present.

In recent years the herd has shifted to new areas. However, herd structure has remained intact, and each year the cows have returned to the traditional calving area of about 1,000 square miles, extending from Kosina Creek southeastward to the Little Nelchina River.

From 1965 to the present most of the herd wintered on the north slopes of the Wrangell Mountains and the south slopes of the Alaska Range east of the Richardson Highway. Major shifts in range use are typical of Alaskan caribou, and adequate evaluation of caribou range includes examination of all segments, those not presently in use as well as those now in use.

Peak population of the Nelchina herd in recent years was estimated at 70,000 in 1962. Since then, the herd has decreased in size, and a count in 1972 suggested that fewer than 20,000 animals remained. Range studies show advanced deterioration of important plant communities.

The McKinley herd has undergone a similar decline from an estimated 30,000 animals prior to 1941 to fewer than 10,000 today.

Caribou occurred on the Kenai Peninsula until the early 1900s, when loss of habitat to extensive fires and intensive hunting caused the herd to become extinct.

The present herd, the result of restocking in 1965 and 1966, now numbers about 250 animals. About 200 of these reside in the northern Kenai Mountains with a smaller group in the flats north of Kenai.

Moose: The moose of the Cook Inlet subregion are linked closely to man's activities (Figure 136b). Much of the habitat results from extensive fires within recent years which have stimulated browse growth. The Kenai National Moose Range, which supports the best known populations, owes the good quality of its habitat mainly to a 350,000 acre fire in 1947. Other major fires occurred in the Matanuska Valley.

The subregion supports a moose population estimated at 15,000 to 17,000 animals, and some of the highest populations per unit area in the world are found near Homer. Much of the winter habitat, particularly near Anchorage, is being eliminated by urban expansion, bringing the animals in close contact with humans as they search for winter food in suburbia.

Dall sheep: These sheep are present in the Alaska Range and the Talkeetna, Chugach, and Kenai Mountains (Figure 136b). Sheep inhabit most of the north slope of the Chugach Range from Turnagain Arm to the Canadian border. Populations are not continuous, however, and some areas within this range contain no sheep while others have large herds. More than 2,000 sheep were counted in the Chugach Range east of the Copper River in 1968 and 1969.

Greatest concentrations of sheep in the Talkeetna Mountains are found in the southern portion of the range. Hunting pressure for rams is fairly heavy due to relatively easy access from the highways, by air, and by all-terrain vehicle. Approximately 100 rams are taken annually in the Talkeetna Mountains.

Both the Alaska Range and Kenai Mountains in the subregion contain significant populations of sheep. Most sheep in the Alaska Range inhabit the north slopes, and relatively few occur within the Southcentral Region. More than 2,000 sheep were counted in the Kenai Mountains in 1968, and about 70 rams are harvested annually.

Mountain goat: Goats occur in low numbers in the Talkeetna Mountains and in moderate numbers in the Kenai Mountains within the subregion (Figure 136b).

Primary waterfowl habitat of the subregion lies in the Matanuska-Susitna River glacial outwash plain and the Kenai lowland. The habitat consists of rain shadow basins surrounded by high mountains and forest vegetation in transition between true rain forest and the dry boreal forest of the Interior. Trumpeter swans that nest on the Kenai lowland are the most important breeding waterfowl. Geese do not nest in appreciable numbers in the subregion, and ducks occur in lower numbers than in interior habitats. During migration, however, some areas become highly impacted with ducks, geese, and swans. As many as 70,000 waterfowl have been estimated to be in the Susitna River valley at one time (Figure 137b).

Coastal areas throughout this subregion support moderate populations of bald eagles and peregrine falcons. Rainy, Broad, and Windy Passes are also migration routes for peregrines which move through the Susitna River valley.

Golden eagles and gyrfalcons occupy upland areas. Great horned owls, great grey owls, and rough-legged hawks are some characteristic raptors of the spruce-birch forest in the more northern areas of the subregion. Other raptors known to breed in this subregion include goshawks, sharp-shinned hawks, red-tailed hawks, Harlan's hawks, marsh hawks, osprey, pigeon hawks, and short-eared owls.

Colonial nesting seabirds are not abundant in this subregion. However, several colonies have been identified and others probably exist. These contain such species as black-legged kittiwakes; glaucous-winged gulls; common and thick-billed murres; pigeon guillemots; horned and tufted puffins; red-faced, double-crested and pelagic cormorants; several forms of auklets; marbled, ancient, and Kittlitz's murrelets; and Arctic terns. Long-tailed jaegers are present, as are various pelagic seabirds such as fulmars, petrels, and shearwaters.

Numerous shorebirds, including semipalmated, American golden and black-bellied plovers; surf birds; ruddy and black turnstones; common snipe; whimbrels; spotted, solitary, pectoral, Baird's, least, semipalmated and western sandpipers; wandering tattlers; greater and lesser yellowlegs; dunlins; short-billed and long-billed dowitchers; Hudsonian godwits; sanderlings; and northern phalaropes are known to breed or occur in the subregion.

Other birds include the black-backed, three-toed, and northern three-toed woodpecker, yellow-shafted flicker, hairy and downy woodpeckers, gray jays, ravens, boreal and black-capped chickadees, redpolls, white-winged crossbills, water pipits, rosy finches, ravens, snow buntings, longspurs, and savannah sparrows.

In addition, summer migrants include gray-cheeked, Swainson's, hermit, and varied thrushes; robins; orange-crowned yellow, myrtle and blackpoll warblers; northern waterthrushes; Bohemian waxwings; bank swallows, white-crowned and fox sparrows; slate-colored juncos; Say's phoebes; and olive-sided and alder or Traill's flycatchers.

Black bear: These bears occur throughout the subregion . Populations vary from relatively high levels along the coasts to moderate levels in the interior. Glacier bears, a unique, blue-color phase of the black bear, inhabit the coastal mountains, especially east of the Suckling Hills.

Brown-grizzly bear: These animals occur on the mainland throughout the subregion and on Hinchinbrook, Montague, Kayak, and Hawkins Islands (Figure 135c). They are less common on the west side of Prince William Sound and are less numerous inland than along the coast.

Wolf: These animals are relatively abundant in the interior portions of the subregion but quite scarce along the Prince William Sound coast. The wolf population of the Nelchina Basin numbers about 300.

Wolverine: Wolverines are abundant inland but not as common along the coast.

Sitka black-tailed deer: Deer in this subregion are primarily confined to islands of Prince William Sound but some occur on the mainland in the Cordova area (Figure 136c). They were originally transplanted here between 1916 and 1923. Recent sightings have been reported from the east side of the Kenai Peninsula, but they have not been confirmed.

Barren ground caribou: The interior portion of the subregion contains a sizeable portion of the Nelchina caribou winter range as well as part of the herd's calving grounds in the west central section (Figure 135c). This herd once numbered about 70,000 animals but has declined in recent years to fewer than 20,000. Winter range deterioration is the suspected cause. No caribou are found along the coastal areas of Prince William Sound. The small Mentasta herd ranges over the eastern portion of the subregion but in recent years has become intermingled with the Nelchina herd and may be losing its identity.

Bison: Two distinct herds, the Chitina and Copper River, exist in the subregion. The Chitina herd numbers about 16 animals and has low calf production (Figure 135c). The Copper River herd numbers about 120 animals. Both herds resulted from transplants from the herd at Big Delta.

Dall sheep: This subregion contains some of the most productive Dall sheep range in the state (Figure 135c). Aerial counts made in 1968 and 1970 indicated at least 1,625 sheep present between McCarthy and the Canadian border alone.

Moose: The subregion supports a moose population estimated to exceed 5,000 animals with greatest concentrations in the Interior (Figure 136c). They are most numerous on the slopes of Mt. Stanford and Mt. Drum, but they are also abundant elsewhere in the subregion. At lower elevations they share the range with caribou. Fires that benefit moose range are detrimental to the range of caribou. Moose in the subregion have suffered a severe decline in recent years which may be due to severe winters, over browsing, competition with snowshoe hares, or a combination of these factors. Moose also occur on the Copper River delta, but there are almost none in the island and fjord country of Prince William Sound.

Mountain goat: Goats are abundant in the Chugach Mountains bordering Prince William Sound, but are present only in low numbers in the Wrangell Mountains and interior portions of the Chugach Mountains (Figure 136c). Heaviest concentrations are along the coast between Day Harbor and Port Dick. The population of the subregion is estimated to be greater than 3,500 goats.

Prince William Sound is an important migration route for many species of waterfowl. There are three obvious routes through the Sound; the outer island route around the Kenai Peninsula, Portage Pass at Whittier, and the Copper River valley (Figure 137c).

Some parts of the Sound are important wintering areas as well. During 1970-71 nearly 57,000 ducks, mostly white-winged, surf, and common scoters, wintered there. During the spring of 1971 there were almost 78,000. Other diving ducks are generally well-distributed throughout the Sound and are commonly encountered in Port Valdez. Among these are Barrow's goldeneye, buffleheads, harlequin ducks, oldsquaws, common and king eiders, and common mergansers.

Greater scaup are widely distributed in the Sound during winter but tend to concentrate over the tidal flats in the eastern end during the migrational buildup. Mallards are the only dabbling ducks which are significant year-round, but pintails, American widgeon, green-winged teal, gadwalls, and shovelers are common in spring. Pintails may be the most common breeding dabblers. Several species of Canada geese either winter or breed in Prince William Sound, and some are believed to be year-round residents, nesting on the timbered islands and wintering in such places as Coghill Flats, Hell's Hole, and Port Fidalgo. Black brant, as well as white-fronted and snow geese in lesser numbers, migrate along the outer fringe of the Sound on their way north each spring.

The Copper River delta and the Bering Glacier outwash plain contain about 15-18 townships of exceptional value to waterfowl. This is the principal nesting ground for the world's population of dusky Canada geese and produces more ducks per square mile than most known habitats in Alaska. Trumpeter swans reach their greatest densities here. In spite of its unique nesting populations, the Copper River delta is probably most important as a staging and feeding area for migratory waterfowl bound to and from Arctic and subarctic nesting grounds to the north. The confluence of the Bremner and Copper Rivers contains several townships of trumpeter swan habitat that are second in importance only to the Copper River delta.

The Nelchina basin contains many large lakes in addition to numerous thaw lakes which dot the eastern section. These provide moderately good duck nesting habitat. The basin adds more than 180,000 ducks to the fall flight, mostly scaup, green-winged teal, widgeons, and mallards as well as a substantial number of trumpeter swans.

Prince William Sound, including all the coastline of the subregion from Icy Bay to Gore Point and most of the offshore islands, is prime habitat for bald eagles, which congregate along salmon streams during spawning runs. A 1970-71 winter survey indicated that there were at least 600 eagles in the Sound. The peregrine falcon inhabits most of this same territory. These birds nest on shelves of cliffs, in cavities in cliffs or high cutbanks, and occasionally in cavities of trees. Peregrines also migrate through Isabel Pass to and from the Interior and Arctic.

The entire coastal area is habitat for seabirds of various species, particularly the colonial nesting birds such as kittiwakes, puffins, murres, murrelets, guillemots, and cormorants. At least 48 major seabird colonies have been identified in this subregion, and undoubtedly many more exist.

The nearly 200 square miles of tidal flats in Orca Inlet and the Copper River delta probably support one of the greatest remaining concentrations of bird life in existence. Typical species are semipalmated plovers, short- and long-billed dowitchers, and knots, dunlins, and western sandpipers. Common snipe and greater and lesser yellowlegs are most often found in the grass flats of the Copper River delta, while surfbirds, black turnstones, black oystercatchers, wandering tattlers, and rock sandpipers inhabit the coasts of the outer islands.

With the exception of water pipits, which are a common part of the beach avifauna, the passerine birds are mostly forest dwellers. These include several types of warblers, western winter wrens, ruby- and golden-crowned kinglets, thrushes, robins, several sparrows, several woodpeckers, northwestern crows, northern shrikes, and others.

The following lists indicate the species which are usually prominent in each of the vegetative types that have been described in Figures 132a, b, and c. No indication of the importance of interspecific relationships is intended. Each of these habitats may also be inhabited by numerous other small mammals such as shrews, voles, and lemmings as well as other species of birds, such as chickadees, woodpeckers, and sparrows.