The
Spotted Owl,
Strix occidentalis, is a species of true owl. It is a resident species of forests in western
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
, where it nests in tree holes, old
bird of preyBirds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as any bird that kills its prey with its talons. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh. In most cases,...
nests, or rock crevices. Nests can be between 13 and 66 yards (12 to 60 meters) high and usually contain two eggs (though some will contain as many as four). It is a strictly nocturnal
owlThe Owls are the order Strigiformes, comprising 200 birds of prey, species. Most are solitary, and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, though a few species specialize in hunting fish. They are found in all regions of the Earth except...
, which feeds on small mammals and birds.
This owl has a length of 43 cm (17 inches), a wingspan of 114 cm (45
inchAn inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
es), and a weight of around 600
gThe gram , ; symbol g, is a unit of mass.Originally defined as "the absolute weight of a volume of pure water equal to the cube of the hundredth part of a metre, and at the temperature of melting ice" , a gram is now defined as one one-thousandth of the SI base unit, the kilogram, or...
(21
ounceThe ounce is a unit of mass with several definitions, the most commonly used of which are equal to approximately 30 grams. The ounce is used in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems...
s).
The
Spotted Owl,
Strix occidentalis, is a species of true owl. It is a resident species of forests in western
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
, where it nests in tree holes, old
bird of preyBirds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as any bird that kills its prey with its talons. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh. In most cases,...
nests, or rock crevices. Nests can be between 13 and 66 yards (12 to 60 meters) high and usually contain two eggs (though some will contain as many as four). It is a strictly nocturnal
owlThe Owls are the order Strigiformes, comprising 200 birds of prey, species. Most are solitary, and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, though a few species specialize in hunting fish. They are found in all regions of the Earth except...
, which feeds on small mammals and birds.
This owl has a length of 43 cm (17 inches), a wingspan of 114 cm (45
inchAn inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
es), and a weight of around 600
gThe gram , ; symbol g, is a unit of mass.Originally defined as "the absolute weight of a volume of pure water equal to the cube of the hundredth part of a metre, and at the temperature of melting ice" , a gram is now defined as one one-thousandth of the SI base unit, the kilogram, or...
(21
ounceThe ounce is a unit of mass with several definitions, the most commonly used of which are equal to approximately 30 grams. The ounce is used in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems...
s). Its
eggsIn most birds and reptiles, an egg is the zygote, resulting from fertilization of the ovum. To enable incubation the egg is usually kept within a favourable temperature range as it nourishes and protects the growing embryo. When the embryo is adequately developed it breaks out of the egg in the...
are a little over 2 inches (50 millimeters) long, and are white and smooth with a slightly grainy texture. The female sits on the eggs and cares for the young, while the male provides food for them. Juvenile Spotted Owls have an average survival rate of 11%, with an average birth rate of .58 owls per pair.
The three sub-species of
Strix occidentalis are
Strix occidentalis caurina (
Northern Spotted OwlThe Northern Spotted Owl, Strix occidentalis caurina, is one of three Spotted Owl subspecies. A Western North American bird in the family Strigidae, genus Strix, it is a medium-sized dark brown owl sixteen to nineteen inches in length and one to one and one sixth pounds. Females are larger than...
),
Strix occidentalis occidentalis (California Spotted Owl), and
Strix occidentalis lucida (often referred to as the
Mexican Spotted Owl). The
Gila WildernessGila Wilderness was designated the world's first wilderness area on June 3, 1924. Along with Aldo Leopold Wilderness and Blue Range Wilderness, the wilderness is part of New Mexico's Gila National Forest. The wilderness is approximately from north to south and east to west...
is home to the largest population of the Mexican sub-species.
The Spotted Owl is similar in appearance to the
Barred OwlThe Barred Owl, Strix varia, is a large typical owl. It goes by many other names, including eight hooter, rain owl, wood owl, and striped owl, but is probably known best as the hoot owl.-Description:...
but has cross-shaped markings on the underparts, whereas the Barred Owl is alternately barred on the breast and streaked on the belly. Barred Owls are larger and grayer than Spotted Owls. In recent years the California and Northern subspecies of Spotted Owl have been displaced by Barred Owls, which are more aggressive, have a broader diet and occur in more varied habitats. Though the two species may hybridize in areas where displacement is occurring, they are quite genetically distinct, for example, differing 13.9% in certain gene sequences.
Conservation
The Northern and southern spotted owl populations are currently listed as threatened in the United States under the
Endangered Species ActThe Endangered Species Act of 1973 is the most wide-ranging of the dozens of United States environmental laws passed in the 1970s...
, which is administered by the
United States Fish and Wildlife ServiceThe United States Fish and Wildlife Service is the unit of the U.S. Department of the Interior dedicated to the management and preservation of wildlife.Units within the FWS include:* National Wildlife Refuge System* * Federal Duck Stamp...
(USFWS).
The Northern Spotted Owl is in rapid decline with about a 7% annual population loss along the northern edge of its range (northern Washington state and south-western British Columbia). Fewer than 30 breeding pairs remain in British Columbia, and the species is expected to be extirpated from Canada within the next few years .
The California spotted owl is not considered to be threatened nor endangered by the USFWS, however, it considered to be a species of special concern by the state of California and the
United States Forest ServiceThe United States Forest Service is an agency of the United States Department of Agriculture that administers the nation's 155 national forests and 20 national grasslands, which encompass 193 million acres...
(USFS).
All subspecies of the spotted owl are often the subject of disagreement between conservationists and loggers, cattle grazers, developers, and other organizations whose activities can affect forest cover. In February 2008, a federal judge reinforced a U.S. Fish and Wildlife Service decision to designate in Arizona, Utah, Colorado and New Mexico as critical habitat for the owl. The decision had been challenged by the Arizona Cattle Growers' Association, but Judge Susan Bolton upheld the designation. According to the Center for Biological diversity, "Having critical habitat will ensure that U.S. Forest Service logging does not limit the bird's recovery or drive it into extinction."
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