HABITAT AND RANGE:
Open terrain that is largely free of
visual obstructions. Virgin prairies,
and unbroken plains make ideal habitat.
Airports and cultivated land are
occasionally used. Burrows with at least
one perch (help improve ability to see
predators and detect prey), and open
space in which to find food seem-to be
preferred.
From
islands off the Pacific Coast, east to
western Minnesota, South Dakota,
Nebraska, central Kansas and Texas, and
southeastern Louisiana; north to
Washington, southern British Columbia
and western Manitoba; south through
California and Mexico to Guatemala. They
also appear in Panama and the tip of
Florida.
PHYSICAL CHARACTERISTICS:
Although burrowing owls lack ear tuft
and a well-defined facial disk, these
pigeon-sized, round-headed birds, with
long lightly feathered legs, are
definitely owls. The yellow-eyed adults
are sandy brown above and white, barred
with brown, below. A white throat, white
"eyebrows", and brown collar also help
to identify this bird. When the wings
are folded over the back, the short
square or slightly rounded tail is
virtually invisible. Young burrowing
owls resemble the adults, but have a
rusty throat.
ADAPTATIONS:
Burrowing owls are not typical owls.
They do not hoot. Instead 3 distinctly
different calls are used. The mournful,
rapidly uttered mating call "coo-coo-roo",
heard in spring on the nesting grounds,
my have given rise to the nickname
"cuckoo owl". A cackling alarm note (cack-cack-cackc-cack)
is given as the bird darts into its hole
or flies away. A wounded or enraged bird
utters a shrill scream and, snapping its
mandible (beak) rapidly, produces a good
imitation of a rattlesnake buzz. If the
intruder (rattlesnake, badger, skunk,
opossum, or man) persists, the owl
throws itself onto its back and strikes
out vigorously with its talons.
Burrowing owls
are not strictly nocturnal, appearing to
make no distinction between day and
night in procuring food. Unlike larger
owls, burrowing owls in spite of their
high profile lifestyle, are not usually
mobbed by other small birds, who my
sense that these tiny owls pose little
threat.
Hopi
Indians identify the burrowing owl with
their god of the dead, Masauu. Since the
owl lives in the underworld, he can thus
be expected to communicate with the dead
and Masauu through subterranean tunnels.
The Gosiutes of Utah and Nevada believe
the burrowing owl was the protective
spirit for brave warriors. Owl feathers
were always worn by members of the Dog
Society (a warrior group). Rattles also
had coverings of owl skins. It was
believed these would frighten off
enemies.
DIET:
Burrowing owls use a variety of methods
to find prey. Diligently running back
and forth on the ground is useful in
picking up nocturnal insects, frogs, and
other small creatures. Hunting from a
perch, and catching prey on the wing are
also successful techniques. Prey items
include: -insects: grasshoppers,
locusts, beetles, crickets,
caterpillars, dragonflies, etc.
-mammals: mice, rats, ground squirrels,
pocket gophers, chipmunks, shrews, young
prairie dogs and cottontails, and even
bats -lizards, snakes, frogs, toads,
salamanders, fishes, scorpions, and
rarely, birds.
REPRODUCTION AND DEVELOPMENT:
Burrowing owls occasionally dig their
own burrows, but seem to prefer to nest
in the abandoned burrows, of prairie
dogs, woodchucks, skunks, foxes, wolves,
armadillos or badgers. After
construction of a nest cavity (about 6"
high and 8" wide, 30" under-round and
5-10 feet from the burrow's entrance),
the same burrow my be used year after
year.
Just prior to
egg-laying (which begins in April), the
male carries chunks of dried cow or
horse dung to the burrow entrance. The
female uses the dung, and a collection
of weed stalks, to line the nest cavity.
Some dung is left at the burrow
entrance. It is believed that the dung
helps to control both temperature and
humidity within the nest cavity; and the
odor my also fool predators, such as a
badger returning to an old den site. In
a study of 25 dung-lined nests, only 2
(8%) were lost to badgers, while 13.of
24 unlined nests (54%) were lost.
STATUS IN WILD:
In 1966, burrowing owls became the first
owls to receive a special status. The
United States Department of the Interior
Red Book listed them as a "rare
species". Two years later they lost this
"rare" status. In 1973 they were
designated "status undetermined". No
specific protection was given, but mere
reasonable use of rodenticides was
encouraged. Apparently indiscriminate
use of rodenticides (carbon disulphide)
in campaigns against ground squirrels
was the primary cause of the burrowing
owls decline. Previously all holes were
poisoned and sealed, no distinction was
made between holes occupied by squirrels
and owls. Now that these chemicals are
being used mere responsibly, the
burrowing owls seem to be holding their
own.
