Biology Reference
In-Depth Information
mans—quite possibly in defense of a nearby nest. According to various accounts, the owl attacked a
twenty-pound dog and flew away with it. The dog's owner then ran after it, shouting at the owl, which
dropped the dog from a height of thirty feet. The dog died; the owl, when later killed, weighed three
and a half pounds.
This feat struck me as somewhere between extraordinarily improbable and just plain impossible.
Leading ornithologists share my skepticism. As Dr. Stuart Houston, one of the foremost great horned
owl experts in North America, put it, “No bird can carry six times its weight.” He and other ornitho-
logists believe that a great horned owl, with its fearsome talons, could kill a twenty-pound animal, but
carrying it off is another matter entirely.
A three-and-a-half-pound great horned owl might possibly be able to carry as much as five or six
pounds for a short distance—a rather amazing feat for a bird—but certainly not twenty pounds. There
was general agreement among the ornithologists with whom I consulted that either the dog weighed a
great deal less than twenty pounds or the owl killed it but didn't carry it off. The great horned owl is an
amazing bird, but it doesn't possess supernatural powers!
The great horned owl has the distinction of being perhaps the earliest nester of any bird throughout
much of its range. Nesting may begin as early as January, with snow piled deep on the ground, and it's
not uncommon for the female, superbly insulated by her thick coat of fluffy feathers, to incubate her
eggs while covered with a mantle of snow.
Great horned owls possess many skills, but nest building isn't among them. In forested areas, horned
owls most commonly lay claim to an old hawk's, crow's, or heron's nest, but a large tree cavity some-
times serves the purpose equally well. In areas that lack suitable tree sites, the female may simply lay
her eggs on a ledge.
Once a nest is established, the female lays one to three eggs, although the usual number is two. In-
cubation takes about a month. Thereafter, the harried parents are forced to hustle after enough meat to
satisfy the rapidly growing appetites of their voracious youngsters. The gawky, homely, fuzzy young
grow rapidly and, after about a month and a half, have become sufficiently feathered to fledge and leave
the nest. If owls can feel anything like relief, their parents must surely experience it at this point!
THE SNOWY OWL
This Arctic resident is a birdwatcher's delight when it descends into southern Canada, the northern tier
of states, and, very occasionally, as far south as Florida, Texas, and central California. Why? There are
several reasons. First, this is a big, showy owl. With a wingspan of nearly five feet and a weight of four
to six pounds, it's the heaviest of our North American owls. It usually stands out like a beacon when it
moves south, because of its imposing size and spectacular plumage—nearly snow white in adult males,
more speckled in adult females, and barred with black in juveniles. Further, the snowy owl
(Nyctea
scandiaca),
while by no means a rare winter visitor far south of its tundra breeding grounds, is just
