Koyukuk National Wildlife Refuge
Encyclopedia
The 3500000 acres Koyukuk National Wildlife Refuge lies within the floodplain
of the Koyukuk River
, in a basin that extends from the Yukon River
to the Purcell Mountains
and the foothills of the Brooks Range
. This region of wetlands is home to fish
, waterfowl
, beaver
and moose
, and wooded lowland
s where bear
s, wolves, lynx
and marten
prowl.
The 750000 acres (3,035.1 km²) Northern Unit of the Innoko National Wildlife Refuge
, commonly known as Kaiyuh Flats, is managed as part of the Koyukuk/Nowitna Refuge Complex. Rich in wetlands, the Northern Innoko is an extremely productive breeding area for migratory waterfowl and fish. The streams and rivers of the refuge complex support three species of salmon
, arctic grayling
, sheefish, and many other fish species. Northern pike, especially those that winter in the shallow lakes of the Northern Innoko National Wildlife Refuge, sometimes grow to record size.
In the Koyukuk's wetlands, breeding waterfowl feast upon water plants and abundant protein-rich invertebrates. Young birds grow quickly in the short, lush summer, and prepare for the fall migration
. As many as 100,000 ducks are hatched and raised on Refuge lands during a single nesting season. Migratory songbirds and raptors also depend on the rich resources of the Koyukuk Refuge for breeding and raising young.
Koyukuk Refuge's Three-Day Slough area, part of the 400000 acres (1,618.7 km²) Koyukuk Wilderness, has some of the most productive moose
habitat in Alaska. This region has, at times, supported more than 10 moose per square mile. Recent counts indicate that some areas still contain densities of five moose or more per square mile. As with much of the refuge big game work, these moose counts are cooperative efforts between the U.S. Fish and Wildlife Service and Alaska Department of Fish and Game
.
Caribou from the migratory Western Arctic Herd, which numbers more than 450,000, often move into the northernmost reaches of the Refuge in winter months in search of lichens that lie beneath the snow. The Koyukuk also supports a resident non-migratory caribou population, the Galena Mountain Herd, which numbers about 300. Wolves, lynx and other furbearers, as well as black
and grizzly bear
s, are found on the Refuge year around.
Floodplain
A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...
of the Koyukuk River
Koyukuk River
The Koyukuk River is a principal tributary of the Yukon River, approximately 500 mi long, in northern Alaska in the United States.It drains an area north of the Yukon on the southern side of the Brooks Range...
, in a basin that extends from the Yukon River
Yukon River
The Yukon River is a major watercourse of northwestern North America. The source of the river is located in British Columbia, Canada. The next portion lies in, and gives its name to Yukon Territory. The lower half of the river lies in the U.S. state of Alaska. The river is long and empties into...
to the Purcell Mountains
Purcell Mountains
The Purcell Mountains are a mountain range in southeastern British Columbia, Canada. They are a subrange of the Columbia Mountains, which includes the Selkirk, Monashee, and Cariboo Mountains. They are located on the west side of the Rocky Mountain Trench in the area of the Columbia Valley, and on...
and the foothills of the Brooks Range
Brooks Range
The Brooks Range is a mountain range in far northern North America. It stretches from west to east across northern Alaska and into Canada's Yukon Territory, a total distance of about 1100 km . The mountains top out at over 2,700 m . The range is believed to be approximately 126 million years old...
. This region of wetlands is home to fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, waterfowl
Waterfowl
Waterfowl are certain wildfowl of the order Anseriformes, especially members of the family Anatidae, which includes ducks, geese, and swans....
, beaver
Beaver
The beaver is a primarily nocturnal, large, semi-aquatic rodent. Castor includes two extant species, North American Beaver and Eurasian Beaver . Beavers are known for building dams, canals, and lodges . They are the second-largest rodent in the world...
and moose
Moose
The moose or Eurasian elk is the largest extant species in the deer family. Moose are distinguished by the palmate antlers of the males; other members of the family have antlers with a dendritic configuration...
, and wooded lowland
Lowland
In physical geography, a lowland is any broad expanse of land with a general low level. The term is thus applied to the landward portion of the upward slope from oceanic depths to continental highlands, to a region of depression in the interior of a mountainous region, to a plain of denudation, or...
s where bear
Bear
Bears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although there are only eight living species of bear, they are widespread, appearing in a wide variety of habitats throughout the Northern...
s, wolves, lynx
Lynx
A lynx is any of the four Lynx genus species of medium-sized wildcats. The name "lynx" originated in Middle English via Latin from Greek word "λύγξ", derived from the Indo-European root "*leuk-", meaning "light, brightness", in reference to the luminescence of its reflective eyes...
and marten
Marten
The martens constitute the genus Martes within the subfamily Mustelinae, in family Mustelidae.-Description:Martens are slender, agile animals, adapted to living in taigas, and are found in coniferous and northern deciduous forests across the northern hemisphere. They have bushy tails, and large...
prowl.
The 750000 acres (3,035.1 km²) Northern Unit of the Innoko National Wildlife Refuge
Innoko National Wildlife Refuge
The Innoko National Wildlife Refuge is a wildlife refuge in western Alaska in the United States. It consists of 3,850,481 acres of which 1,240,000 acres is designated a wilderness area. It is the fifth-largest National Wildlife Refuge in the United States. The refuge is administered from offices...
, commonly known as Kaiyuh Flats, is managed as part of the Koyukuk/Nowitna Refuge Complex. Rich in wetlands, the Northern Innoko is an extremely productive breeding area for migratory waterfowl and fish. The streams and rivers of the refuge complex support three species of salmon
Salmon
Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...
, arctic grayling
Arctic grayling
Arctic grayling is a species of freshwater fish in the salmon family of order Salmoniformes. It comprises five subspecies native to the Nearctic and Palearctic ecozones. T. a. arcticus is widespread throughout the Arctic and Pacific drainages in Canada, Alaska, and Siberia, as well as the upper...
, sheefish, and many other fish species. Northern pike, especially those that winter in the shallow lakes of the Northern Innoko National Wildlife Refuge, sometimes grow to record size.
In the Koyukuk's wetlands, breeding waterfowl feast upon water plants and abundant protein-rich invertebrates. Young birds grow quickly in the short, lush summer, and prepare for the fall migration
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
. As many as 100,000 ducks are hatched and raised on Refuge lands during a single nesting season. Migratory songbirds and raptors also depend on the rich resources of the Koyukuk Refuge for breeding and raising young.
Koyukuk Refuge's Three-Day Slough area, part of the 400000 acres (1,618.7 km²) Koyukuk Wilderness, has some of the most productive moose
Moose
The moose or Eurasian elk is the largest extant species in the deer family. Moose are distinguished by the palmate antlers of the males; other members of the family have antlers with a dendritic configuration...
habitat in Alaska. This region has, at times, supported more than 10 moose per square mile. Recent counts indicate that some areas still contain densities of five moose or more per square mile. As with much of the refuge big game work, these moose counts are cooperative efforts between the U.S. Fish and Wildlife Service and Alaska Department of Fish and Game
Alaska Department of Fish and Game
The Alaska Department of Fish and Game is a department within the government of Alaska. The Department of Fish and Game manages Alaska's fish, game, and aquatic plant resources.-History:...
.
Caribou from the migratory Western Arctic Herd, which numbers more than 450,000, often move into the northernmost reaches of the Refuge in winter months in search of lichens that lie beneath the snow. The Koyukuk also supports a resident non-migratory caribou population, the Galena Mountain Herd, which numbers about 300. Wolves, lynx and other furbearers, as well as black
American black bear
The American black bear is a medium-sized bear native to North America. It is the continent's smallest and most common bear species. Black bears are omnivores, with their diets varying greatly depending on season and location. They typically live in largely forested areas, but do leave forests in...
and grizzly bear
Grizzly Bear
The grizzly bear , also known as the silvertip bear, the grizzly, or the North American brown bear, is a subspecies of brown bear that generally lives in the uplands of western North America...
s, are found on the Refuge year around.