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Exploring the beautiful nature of California
California Nature: Owls
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Barn owls are medium to large sized owls
with large heads and characteristic heart-shaped faces. They
have long strong legs with powerful talons. There are 16 species
world wide, 1 North American species, and 1 Californian species.
Typical owls are small to large solitary nocturnal birds of
prey. They have large forward-facing eyes and ears, a hawk-like
beak, and a conspicuous circle of feathers around each eye
called a facial disk. There are 195 species world wide, 21 North
American species, and 13 Californian species.
The Barred Owl is a medium-sized gray-brown Owl streaked with
white horizontal barring on the chest and vertical barring on
the belly. They are round-headed with a whitish/brown facial
disk with dark brown trim. The eyes are brown, and the beak is
yellow and almost covered by feathers. They have a long tail.
There is no difference in plumage between males and the larger
females. A very opportunistic hunter, a Barred Owl can sometimes
be seen hunting before dark. This typically occurs during the
nesting season or on dark and cloudy days. A Barred Owl will use
a perch, from where it dives upon its prey - meadow voles are
its main prey, followed by shrews and deer mice.
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California supports the largest remaining
breeding and wintering populations of western
burrowing owls.
The burrowing owl is a pint-sized bird that
lives in open, treeless areas. The burrowing owl
spends most of its time on the ground, where its
sandy brown plumage provides camouflage from
potential predators. One of California's
smallest owls, it averages nine inches in height
with a wingspan of 21 inches. The burrowing owl
lacks the ear tufts of the more familiar
woodland owls. Bright yellow eyes and a white
chin accent the face. Unusually long legs
provide additional height for a better view from
its typical ground-level perch.
Burrowing owls inhabit open native prairies and
cleared areas that offer short groundcover
including pastures, agricultural fields, golf
courses, airports, and vacant lots in
residential areas. Burrowing owls live as single
breeding pairs or in loose colonies consisting
of two or more families.
Unlike most owls, burrowing owls are active
during both day and night. During the day, they
are usually seen standing erect at the mouth of
the burrow or on a nearby post. When disturbed,
the owl bobs in agitation and utters a
chattering or clucking call. In flight,
burrowing owls typically undulate as if they are
flying an invisible obstacle course. They also
can hover in midair, a technique effective for
capturing food. Burrowing owls mainly eat
insects, especially grasshoppers and beetles.
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Burrowing owls in the Imperial Valley nest
almost entirely in ground-squirrel burrows along earthen
irrigation canals and drains. They represent nearly half the
state's breeding pairs. Once common in California, burrowing
owls have been driven out of much of the state, with large
populations primarily in areas of intensive agriculture,
including parts of the Central Valley, along the lower Colorado
River and the Imperial Valley.
New surveys show a 27-percent drop in the number of breeding
burrowing owls in California's Imperial Valley and provide some
of the most striking evidence yet that the species is badly in
need of state protections. It is unknown what is causing the
Imperial owl decline, but loss of suitable foraging areas from
fallowing of agricultural fields due to water transfers and
ground-squirrel eradication programs may play a role. There is
no evidence that the Imperial owls are moving elsewhere in
California. Burrowing owls face multiple significant threats,
including habitat loss and fragmentation by urban development,
elimination of burrowing rodents and destruction of burrows,
pesticides, predation by nonnative species, vehicle strikes,
collisions with wind turbines and shooting.
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The California Spotted Owl is about 17.5 inches long and has a
wingspan from 37 to 44 inches. It is nicknamed the Hoot owl
because if its call. It is rare to see one of these owls in the
wild as they prefer the deepest parts of a dense fir forest. The
California Spotted Owl enjoys preening, which means trimming or
dressing its feathers with its beak.
This subspecies of the Spotted Owl is found in Sierra Nevada and the Southern Coast ranges. Sadly, its population is has been declining annually by 10% throughout the 1990’s, and is in danger of extinction. A petition was filed to have the California Spotted Owl listed as an endangered species, but after a year-long study the U.S. Fish and Wildlife Service decided that the owl does not warrant protection under the Endangered Species Act.
The California Spotted Owl enjoys snacking on mice, rats, and
small songbirds. The California Spotted Owl's only natural enemy is the Great-Horned Owl. This is good since the Spotted Owl had very limited offensive capabilities. These birds lay their eggs on whatever surface is available at the time. They lay two to four eggs each year between March and mid-May. The California Spotted Owl lives as long as 17 years, although the survival rate for the young is quite low.
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The Great horned owl has a wide range and habitat, but are always a permanent resident of their chosen territory. There are almost no predators to the adult Great Horned Owl, however they are at times killed in fights with eagles, snowy owls and many times other great horns, which does end in cannibalism at times. The Great Horned Owl will sit at night, on a high tree or perch, waiting for a prey animal and then swoop down on it, and usually do not miss their strike. Great horned owl prey will include rats, squirrels, mice, moles, voles, marmots, skunks, shrews, bats, weasels, gerbils and even porcupines.
The Great Horned Owl has incredible hearing and excellent vision in very low light. Their hearing is much better so far as depth perception than that of a human.. This is possible because their ears are not placed at the same elevation on their heads but rather are typically one, a bit higher than the other. One interesting fact about Great Horned owls is that their eyes are not movable. Rather than turning the eye in its socket the owl must turn its head instead. Great Horned Owls are some of the earliest-breeders in North America, many times breeding in mid to late January or early February. They select their mates in December and are often heard calling to each other.
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