The Snowy Owl Is Quirkier Than You'd Expect

While the Owl Research Institute's initial research focused on the predator-prey relationship between the snowy owl and brown lemming — theses large owls' primary food source — Holt and his crew have since learned much more about this regal and charismatic bird, also known as the snow owl, great white owl from the North and white owl.

Interestingly enough, of the 250 species of owls in the world, the snowy owl (Bubo scandiaca) has arguably proved to be the most captivating, with the ORI's work with this particular animal always generating the most attention, questions and admiration among wildlife enthusiasts.

"Owls, in general, are one of the most popular and most recognized groups of birds in the world," says Holt. "But for reasons I'm not even sure of, when you take a white snowy owl out in front of everyone, people just say, 'Ah.' That goes for white Arctic animals, in general. I don't know what it is, perhaps some angelic quality or purity, but people kind of get excited when they see the white snowy owl."

Breeding season for the snowy owl takes place during what is know as "arctic summer," when temperatures rises slightly in the areas surrounding the North Pole. Once winter falls, the snowy owls' nest is vacated as they pursue the (to them) warmer weather of the Canadian arctic and other snowy parts of the world.

Lovers of the majestic snowy owl can hit the avian lottery if they're lucky enough to witness what's known as an irruption: a periodic phenomenon when hordes of mostly young owls (4 to 6 months old) migrate south from their northern breeding grounds in the Arctic tundra to southern Canada and the Northern U.S., from as far as Seattle to Boston.

When one of these sporadic irruptions occurs, people will flock by the hundreds of thousands to go view these birds in their first year of life, according to Holt. "People who don't have any interest in owls even head out to look at them," he says, "often traveling across state boundaries."

Although migrating snowy owls typically stick to North America and the colder regions of northern Eurasia, juvenile snowy owls have been known to travel great distances to locate prey. On rare occasions, snowy owls have been spotted as far south as California, Texas and even Hawaii.

The snowy owls are one of the only owls in the world that display distinct color differences between the male and female.

When they're young, they both look like females, which retain dark brown bars and spots on their white face and plumage throughout their lives, according to Holt. They have bright yellow at birth, which you can see in both male snowy owls and females.

"As the owls age the females retain most of their darkness," says Holt. "And some males lose their markings almost completely and become a bright fluorescent white. It takes three years for males to become almost pure white."

Like the females, however, some male snowy owls never lose their dark markings. "We think that has to do with special selection," says Holt. "Young males that kind of resemble females do not breed; only older males who become bright white at 3 to 4 years old maintain territories and breed."

"Females are more dominant as far as aggression goes, while the adult male is faster and more handsome," says Holt. "Females can weigh 4 to 5 pounds (1.8 to 2.2 kilograms) and males are in the 3-pound (1.3-kilogram) range. The female also has a wing span of about 4.5 to 5 feet (1.3 to 1.5 meters), with the wing span on the male a little less."

An adult female snowy owl grows even larger than North America's imposing great horned owl. The great horned owl is ranked as the fifth largest owl species in the world, while the largest is the Blakiston's Fish Owl — native to Russia, China and Japan — featuring over 6 feet (1.8 meters) of wingspan.

"When lemmings are high, snowy owls have a good year," says Holt, who reports that snowy owls in his study range have killed and eaten a total of 45,000 to 50,000 of these small rodents through the years. "When lemmings are low, they have a bad year, and might refrain from breeding or have a smaller number of chicks."

When lemmings are scarce, he adds, they'll switch over to wild birds and shore birds, such as ducks or gulls. In desperate times, snowy owls have also taken to hunting fish, frogs, crabs and bugs. But t

But lemmings are more that just a food source; they also play a role in courtship. According to Holt:

When snowy owls return to their Arctic coastal breeding grounds to look for a mate in late April or May, the tundra is still frozen and often snow-covered.

"They use their body heat, feet and bills to dig out a bowl about 10 inches (25 centimeters) wide and 3 to 4 inches (8 to 10 centimeters) deep on a high mound or ridge, so the female can lay her eggs," says Holt.

"The female will have some 10 to 12 eggs in good lemming years," he continues, "with the average at around five eggs. After about 32 to 35 days, the eggs will hatch one at a time in the order in which they were laid (or asynchronously, which means you'll have chicks in the nest ranging anywhere from 2 to 10 days old). Only the female incubates the eggs, and the male brings in food and protects her from foxes, polar bears or other predators."