Posted by: Judy Mukai, Docent
Photos by: Dennis Dow/Woodland Park Zoo
Rarely seen in the wild, great gray owls are the newest
residents in Northern Trail. Often called “great gray ghosts,” “phantoms of the
North” or “spectral owls,” great gray owls live up to their name. They are the
largest North American owl, standing up to 2.75 feet tall. Their huge, round
heads and distinctive facial disks create a most impressive appearance.
However, they are not the heaviest owls; they look big but only weigh between
1.5 to 3.7 pounds. Great gray owls have extremely fluffy plumage on their head
and body and densely feathered toes. The size and plumage befit a bird of the
far North. The birds range throughout northern North America and Eurasia
especially in dense boreal forests. Their mottled and streaked gray/brown
coloration provides excellent camouflage in the trees.
Our great gray owls, Hedwig and Neville, moved from the
Temperate Forest in late July and have settled into the Northern Trail.
Wild-hatched in Alaska, Hedwig suffered a broken wing and
was rescued by U.S. Fish and Wildlife. She never recovered sufficiently for
release and came to us from Chicago’s Lincoln Park Zoo in 2001. Hedwig can
glide or hop downwards and hop up to perches. Neville is a rare, captive-bred
great gray owl. The young 3-year-old male came from Calgary Zoo in 2012 as a mate
for Hedwig. Now 6 years old, he brings her courtship gifts of food each
spring. While she has laid eggs, none have been fertile. At an age of nearly
32, she may be post-reproductive. At the zoo, great gray owls may live up to 40
years and between 13 and 16 years in the wild.
Great gray owls, as well as other raptors, require special
care. Our staff meets the specific, personal needs of each individual bird. For
example, Hedwig rejects mice if they are wet, and she prefers white mice over
dark ones. Especially during hot weather, keepers mist the raptors for cooling
and to encourage preening. Hedwig readily participates. She hops down, opens
her wings, turns around, presents and opens her tail feathers. Afterwards, she
preens her feet for 15 to 30 minutes.
Great gray owls require intact forests for nest sites and bonded pairs often use the same
hollowed tree stumps or abandoned raptor or raven nests for many years. Once
they leave the nest, the owlets (usually three) require tall trees for climbing
and learning to fly, as well as for safety. Threats come from raptors and
ravens, but also lynx, fishers, martens, wolverines and humans. The extremely
protective parents will even take on black bears near their nests!
Hunting strategies for great gray owls use typical owl acute
hearing and low-light vision, but with special twists. Their huge facial disk
combined with very asymmetrical ears enable them to hear prey, such as
rodents, under very thick snow in the winter or deep inside burrows during the
summer. These crepuscular (dawn and dusk) hunters plunge head first from a
perch after prey, then invert in a split second to capture the prey in their
talons. They can even break through snow crust thick enough to support a person
weighing more than 170 pounds!
On an animal viewing trip to Yellowstone National Park, I
was lucky to see a great gray owl. Sighting one is rare enough to cause an “owl
jam” (bison, wolves and bears create most traffic jams). While some visitors
merely drove past, the park ranger shared his excitement on seeing this phantom
species. We stopped and watched the owl perched in a tree near the road.
Eventually, it silently swooped down for prey. The “owl jam” lasted long enough
for a browsing black bear to wander nearby and cause another jam.
Listen for the distinctive springtime courtship or
territorial hoots from Neville. The low-pitched, rhythmic whoo, hoo, hoo, hoo,
hoo will let you know who’s new in Northern Trail.
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| Photo by Jeremy Dwyer-Lindgren, Woodland Park Zoo |
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