Oaks Bottom Wildlife Refuge
Encyclopedia
Oaks Bottom Wildlife Refuge is a city park of about 141 acres (57.1 ha) in southeast Portland
, in the U.S. state of Oregon
. Located in a floodplain along the east bank of the Willamette River
near Sellwood
, the park is known for attracting a wide variety of birds. In 1988, the park was named Portland's first wildlife refuge, and in 2004, it was designated the city's first migratory bird park.
. The Corridor is a hiking and biking path that also runs parallel to the river between Sellwood and downtown Portland. Between the lake and the Corridor is a Portland Traction rail line on a berm
. Slightly south of the refuge are Sellwood Park
and Sellwood Riverfront Park
, and Oaks Amusement Park
is to the west, near the river. To the east, the top of a bluff
above the lake is mainly residential, though one of the buildings is a mausoleum
and crematorium with a huge Great Blue Heron
mural overlooking the wetland
s. A 1 miles (1.6 km) hiking trail wraps around the east side of the lake beneath the bluff. A side trail connects the east trail with Sellwood Park. To the north are mixed woodlands, shrubs, and a few open fields, and a trail crossing the north section of the refuge links the Corridor to a parking lot at the top of the bluff. West of the north part of the refuge are two islands, East and Hardtack, that belong to the Ross Island
group in the Willamette. Ross Island is the site of a heron rookery
.
that the city acquired in 1969 to prevent its development as industrial land. The city later filled the north end of the park with debris from construction of Interstate 405
through downtown Portland. The plan in the early 1970s was to fill the rest of the wetlands and to use the space for museums, perhaps a motocross
course, and a gondola lift
to transport visitors from the top of the bluff to the park. Public pressure from the Audubon Society of Portland
, the Sellwood-Moreland Improvement Society, and The Nature Conservancy
helped persuade the city to stop filling the wetlands. In 1988, after many years of debate, officials designated Oaks Bottom as the first urban wildlife refuge in Portland. Since then, Friends of Oaks Bottom, a volunteer group, has helped the city's parks department with trail maintenance, habitat restoration, and information services.
In 2004, the park was named the city's first migratory bird park. Portland was one of five cities to receive $50,000 grants from the US Fish and Wildlife Service to establish such parks. Thousands of migratory birds visit the refuge during their annual north–south flights.
As of 2010, more than 185 bird species have been recorded in the refuge including herons, egret
s, hawk
s, Osprey
, shorebird
s, gull
s, tern
s, hummingbird
s, woodpecker
s, grebe
s, falcon
s, vulture
s, waterfowl
, and many others. Vegetation, which varies from one part of the refuge to another, includes Oregon white oak, Pacific Madrone, ash, and black locust trees; ferns, Oregon-grape
, Scotch broom
, and poison oak, as well as rushes, sedges
, and other plants. Invasive species, gradually being replaced by physical removal and burning, include reed canary grass
, purple loosestrife, Himalayan blackberry
, and others.
To regulate the flow of water into and out of the wetlands, the parks department adds or removes boards at a small dam near the railroad berm. The idea is to replicate conditions that existed when the wetlands were fully connected to the river. Part of the water in the wetlands comes from natural springs
, and part of the water comes from the river, when it runs high in the winter. Beaver
s have at times foiled the plan by damming the small stream that carries water between the lake and the river. The parks department has foiled the rodents by running a perforated pipe through the beaver dam.
Portland, Oregon
Portland is a city located in the Pacific Northwest, near the confluence of the Willamette and Columbia rivers in the U.S. state of Oregon. As of the 2010 Census, it had a population of 583,776, making it the 29th most populous city in the United States...
, in the U.S. state of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
. Located in a floodplain along the east bank of the Willamette River
Willamette River
The Willamette River is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is long, lying entirely in northwestern Oregon in the United States...
near Sellwood
Sellwood, Portland, Oregon
Sellwood-Moreland is a neighborhood on a bluff overlooking the Willamette River in Southeast Portland, Oregon, bordering Westmoreland to the north, Eastmoreland to the east, and the city of Milwaukie to the south...
, the park is known for attracting a wide variety of birds. In 1988, the park was named Portland's first wildlife refuge, and in 2004, it was designated the city's first migratory bird park.
Description
The enlongated park, which parallels the river, includes a large shallow lake on the east side of the Springwater CorridorSpringwater Corridor
The Springwater Corridor Trail is a bicycle and pedestrian rail trail in the Portland metropolitan area in Oregon, United States. It follows a former railway line of the same name in its route from Boring, through Gresham, to Portland, where it ends near the Eastbank Esplanade. A large segment...
. The Corridor is a hiking and biking path that also runs parallel to the river between Sellwood and downtown Portland. Between the lake and the Corridor is a Portland Traction rail line on a berm
Berm
A berm is a level space, shelf, or raised barrier separating two areas. Berm originates in the Middle Dutch and German berme and came into usage in English via French.- History :...
. Slightly south of the refuge are Sellwood Park
Sellwood Park
Sellwood Park is a city park of about in southeast Portland, in the U.S. state of Oregon. Located at Southeast Seventh Avenue and Miller Street, the park includes courts for tennis and basketball; fields for soccer, baseball, softball, and football; picnic areas; a horseshoe pit; a playground;...
and Sellwood Riverfront Park
Sellwood Riverfront Park
Sellwood Riverfront Park is a city park of about in southeast Portland, in the U.S. state of Oregon. Located at Southeast Spokane Street and Oaks Parkway, the park has paths, picnic tables, a stage, a boat dock on the Willamette River, restrooms, and a dog off-leash area.Formerly a mill site...
, and Oaks Amusement Park
Oaks Amusement Park
Oaks Park is a small amusement park located south of downtown Portland, Oregon USA, near the Sellwood Bridge. The park includes midway games, about two dozen rides that operate seasonally, a skating rink that is open all-year, and picnic grounds.- Rides :...
is to the west, near the river. To the east, the top of a bluff
Cliff
In geography and geology, a cliff is a significant vertical, or near vertical, rock exposure. Cliffs are formed as erosion landforms due to the processes of erosion and weathering that produce them. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually...
above the lake is mainly residential, though one of the buildings is a mausoleum
Mausoleum
A mausoleum is an external free-standing building constructed as a monument enclosing the interment space or burial chamber of a deceased person or persons. A monument without the interment is a cenotaph. A mausoleum may be considered a type of tomb or the tomb may be considered to be within the...
and crematorium with a huge Great Blue Heron
Great Blue Heron
The Great Blue Heron is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North and Central America as well as the West Indies and the Galápagos Islands. It is a rare vagrant to Europe, with records from Spain, the Azores and England...
mural overlooking the wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
s. A 1 miles (1.6 km) hiking trail wraps around the east side of the lake beneath the bluff. A side trail connects the east trail with Sellwood Park. To the north are mixed woodlands, shrubs, and a few open fields, and a trail crossing the north section of the refuge links the Corridor to a parking lot at the top of the bluff. West of the north part of the refuge are two islands, East and Hardtack, that belong to the Ross Island
Ross Island (Oregon)
Ross Island is the main island of a four-island cluster in the Willamette River in Portland, Oregon, in the United States. The islands, covering a total of about , are owned mainly by Ross Island Sand and Gravel , which mined them extensively between 1926 and 2001...
group in the Willamette. Ross Island is the site of a heron rookery
Rookery
A rookery is a colony of breeding animals, generally birds. A rook is a Northern European and Central Asian member of the crow family, which nest in prominent colonies at the tops of trees. The term is applied to the nesting place of birds, such as crows and rooks, the source of the term...
.
History
Before the Bottom became a park, the raised bed of the rail line had largely separated the wetlands from the river. The south part of the wetlands had been altered by a sanitary landfillLandfill
A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...
that the city acquired in 1969 to prevent its development as industrial land. The city later filled the north end of the park with debris from construction of Interstate 405
Interstate 405 (Oregon)
Interstate 405 is a short Interstate Highway in Portland, Oregon. It forms a loop from Interstate 5 that travels through downtown Portland west of the Willamette River.-Route description:...
through downtown Portland. The plan in the early 1970s was to fill the rest of the wetlands and to use the space for museums, perhaps a motocross
Motocross
Motocross is a form of motorcycle sport or all-terrain vehicle racing held on enclosed off road circuits. It evolved from trials, and was called scrambles, and later motocross, combining the French moto with cross-country...
course, and a gondola lift
Gondola lift
A gondola lift is a type of aerial lift, normally called a cable car, which is supported and propelled by cables from above. It consists of a loop of steel cable that is strung between two stations, sometimes over intermediate supporting towers. The cable is driven by a bullwheel in a terminal,...
to transport visitors from the top of the bluff to the park. Public pressure from the Audubon Society of Portland
Audubon Society of Portland
The Audubon Society of Portland is a non-profit environmental organization dedicated to wildlife conservancy in Portland, Oregon, U.S.Founded in 1902 and incorporated in 1909, it is one of the oldest such organizations in the world....
, the Sellwood-Moreland Improvement Society, and The Nature Conservancy
The Nature Conservancy
The Nature Conservancy is a US charitable environmental organization that works to preserve the plants, animals, and natural communities that represent the diversity of life on Earth by protecting the lands and waters they need to survive....
helped persuade the city to stop filling the wetlands. In 1988, after many years of debate, officials designated Oaks Bottom as the first urban wildlife refuge in Portland. Since then, Friends of Oaks Bottom, a volunteer group, has helped the city's parks department with trail maintenance, habitat restoration, and information services.
In 2004, the park was named the city's first migratory bird park. Portland was one of five cities to receive $50,000 grants from the US Fish and Wildlife Service to establish such parks. Thousands of migratory birds visit the refuge during their annual north–south flights.
Flora and fauna
Egret
An egret is any of several herons, most of which are white or buff, and several of which develop fine plumes during the breeding season. Many egrets are members of the genera Egretta or Ardea which contain other species named as herons rather than egrets...
s, hawk
Hawk
The term hawk can be used in several ways:* In strict usage in Australia and Africa, to mean any of the species in the subfamily Accipitrinae, which comprises the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter genus includes goshawks,...
s, Osprey
Osprey
The Osprey , sometimes known as the sea hawk or fish eagle, is a diurnal, fish-eating bird of prey. It is a large raptor, reaching more than in length and across the wings...
, shorebird
Wader
Waders, called shorebirds in North America , are members of the order Charadriiformes, excluding the more marine web-footed seabird groups. The latter are the skuas , gulls , terns , skimmers , and auks...
s, gull
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
s, tern
Tern
Terns are seabirds in the family Sternidae, previously considered a subfamily of the gull family Laridae . They form a lineage with the gulls and skimmers which in turn is related to skuas and auks...
s, hummingbird
Hummingbird
Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings...
s, woodpecker
Woodpecker
Woodpeckers are near passerine birds of the order Piciformes. They are one subfamily in the family Picidae, which also includes the piculets and wrynecks. They are found worldwide and include about 180 species....
s, grebe
Grebe
A grebe is a member of the Podicipediformes order, a widely distributed order of freshwater diving birds, some of which visit the sea when migrating and in winter...
s, falcon
Falcon
A falcon is any species of raptor in the genus Falco. The genus contains 37 species, widely distributed throughout Europe, Asia, and North America....
s, vulture
Vulture
Vulture is the name given to two groups of convergently evolved scavenging birds, the New World Vultures including the well-known Californian and Andean Condors, and the Old World Vultures including the birds which are seen scavenging on carcasses of dead animals on African plains...
s, waterfowl
Waterfowl
Waterfowl are certain wildfowl of the order Anseriformes, especially members of the family Anatidae, which includes ducks, geese, and swans....
, and many others. Vegetation, which varies from one part of the refuge to another, includes Oregon white oak, Pacific Madrone, ash, and black locust trees; ferns, Oregon-grape
Oregon-grape
Oregon-grape is an evergreen shrub related to the barberry. Some authors place Mahonia in the barberry genus, Berberis...
, Scotch broom
Cytisus scoparius
Cytisus scoparius, the Common Broom and Scotch Broom, syn. Sarothamnus scoparius, is a perennial leguminous shrub native to western and central Europe,....
, and poison oak, as well as rushes, sedges
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
, and other plants. Invasive species, gradually being replaced by physical removal and burning, include reed canary grass
Reed canary grass
Reed canarygrass, Phalaris arundinacea, is a tall, perennial bunchgrass that commonly forms extensive single-species stands along the margins of lakes and streams and in wet open areas, with a wide distribution in Europe, Asia, northern Africa and North America.-Description:The stems can reach 2.5...
, purple loosestrife, Himalayan blackberry
Rubus armeniacus
Rubus armeniacus, Armenian Blackberry or Himalayan Blackberry, is a species of Rubus in the blackberry group Rubus subgenus Rubus series Discolores Focke. It is native to Armenia in southwest Asia, and widely naturalised elsewhere...
, and others.
To regulate the flow of water into and out of the wetlands, the parks department adds or removes boards at a small dam near the railroad berm. The idea is to replicate conditions that existed when the wetlands were fully connected to the river. Part of the water in the wetlands comes from natural springs
Spring (hydrosphere)
A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...
, and part of the water comes from the river, when it runs high in the winter. 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...
s have at times foiled the plan by damming the small stream that carries water between the lake and the river. The parks department has foiled the rodents by running a perforated pipe through the beaver dam.