Snowy Owl
SNOWY OWL
The snowy owl (Nyctea scandiaca) is in the order called Strigiformes, which includes all the owls. The snowy owl is probably the most striking and distinctive
of the world’s 146 species of owls, and it is the only white owl in North America.
SIZE: The female snowy owl is larger and heavier than the male, with a wingspan of 4½–5 feet (1.4–1.5 m), a height of 20–27 inches (51–69 cm) and a weight of
3½–4½ pounds (1.6–2 kg). Snowy owls have a large, round head with yellow eyes and black beak and talons.
COLOR: Male snowy-owl feathers are nearly all white with little barring, while the females have white feathers with thick, dark bars.
SPEED: Snowy owls generally fly less than 30 miles per hour (48 km/hr) but they can reach speeds exceeding 50 miles per hour (80 km/hr). These faster speeds
are used in defense of their nest, eggs and chicks.
LONGEVITY: Snowy owls live about ten years in the wild but have survived up to 35 years in captivity.
REPRODUCTION: Snowy owls arrive in their breeding grounds in northern Alaska by mid-to-late May. The nest is located on a prominent, well-drained mound that provides a commanding view of the surrounding tundra area. The female scratches a hollow in the tundra to protect the eggs from spring winds and snowstorms. Some moss and feathers may be added to the simple nest. The male performs display flights and also displays on the ground. The male mounts the female and mating is quick. All during the nesting season the male maintains a nesting territory with loud hooting and will attack intruding owls, wolves and researchers. The number of eggs laid, ranging from four to sixteen, is dependent upon the abundance of prey.
When prey is less abundant the owls lay fewer eggs. The female lays an egg every two days, and she begins incubating as soon as the first egg is laid. During incubation the male provides all the prey for himself and the female. The eggs begin hatching after 33 days of incubation, in the order they were laid, at two-day intervals. The chicks are accordingly different sizes. If the food supply should become insufficient, the younger chicks in the snowy owl’s nest will be unable
to compete with their older siblings. The younger birds may starve or be eaten by their nest mates. The chicks that survive turn from downy white to a fluffy gray, and at ten days old turn nearly black. The chicks leave the nest when they are three to four weeks old, well before they can fly. The adults continue to feed the chicks. The young begin to fly (fledge) at about seven to eight weeks old, and they are completely independent at about nine weeks.
SOCIAL STRUCTURE: Outside of the breeding season, snowy owls usually are solitary.
DISTRIBUTION: Snowy owls breed in Alaska’s Arctic tundra, but during the winter they may be found as far south as California, Georgia and Texas.
MOVEMENTS AND MIGRATION: During the winter some snowy owls stay on the breeding grounds in the Arctic, while others migrate or wander as far south as the northern contiguous United States, with exceptional sightings recorded as far south as California, Georgia and Texas.
HABITAT: Snowy owls are synonymous with the open Arctic tundra. During the winter they may migrate south where they use open habitats, including prairies, marshes or shorelines, to find prey.
PREY: Snowy owls can capture and eat a variety of prey items including hare, ptarmigan and other birds, but lemmings are their primary prey. During the winter many snowy owls migrate to areas where prey is available and abundant, including meadow mice (voles), white-footed mice, deer mice, rats, pheasants, fish and carrion.
PREDATORS: Snowy owls are very alert and aggressive. They will attack intruders in their nesting territory. However, foxes and wolves do take the chicks. Jaegers, a predatory bird, can take the owls’ eggs and chicks. In some areas of Alaska, snowy owls are killed legally for human consumption. A popular technique used is to put a leg-hold trap on top of a post in the middle of the flat tundra. To gain a better hunting vantage point, the owl will land on the post and is trapped easily.
PREDATORY CHARACTERISTICS: Lemmings are snowy owls’ primary prey. Lemming populations are cyclic, and an abundant population can crash in less than a year. One population of lemmings may be very high while a neighboring population may be very sparsely populated. This makes for patchy prey, which predators try to locate. To adapt to the patchy prey, snowy owls are nomadic; they can breed in a different location every year. This allows the owls to nest wherever lemmings are most abundant.
CURRENT STATUS: Snowy owl populations are healthy in Alaska.
ECOLOGY/CONSERVATION: Snowy owls swallow small prey whole. Large prey, such as ptarmigan and hares, are torn apart. Any bones, teeth, feathers and fur eaten are non-digestible; they are compacted and then regurgitated as pellets. Since a snowy owl must eat up to a dozen mice each day, large accumulations of pellets can be located around perches. Biologists interested in owl and small mammal ecology can extract the bones from the pellets to determine the number and type of prey taken by the owls. Understanding the population dynamics of the prey helps scientists to understand the predator.
References:
Wright, Bruce A., 2011. Alaska Predators, Their Ecology and Conservation. Hancock House Publishing. 119 pages. http://www.hancockhouse.com/products/alapre.htm
Other species:
Pacific sleeper sharks in Alaska
Salmon sharks in Alaska
Great white sharks in Alaska
Bald Eagle
Gyrfalcon
Great Horned Owl
Black Bears
Brown Bears
Polar Bears
Orcas
Wolves
Wolverine
The snowy owl (Nyctea scandiaca) is in the order called Strigiformes, which includes all the owls. The snowy owl is probably the most striking and distinctive
of the world’s 146 species of owls, and it is the only white owl in North America.
SIZE: The female snowy owl is larger and heavier than the male, with a wingspan of 4½–5 feet (1.4–1.5 m), a height of 20–27 inches (51–69 cm) and a weight of
3½–4½ pounds (1.6–2 kg). Snowy owls have a large, round head with yellow eyes and black beak and talons.
COLOR: Male snowy-owl feathers are nearly all white with little barring, while the females have white feathers with thick, dark bars.
SPEED: Snowy owls generally fly less than 30 miles per hour (48 km/hr) but they can reach speeds exceeding 50 miles per hour (80 km/hr). These faster speeds
are used in defense of their nest, eggs and chicks.
LONGEVITY: Snowy owls live about ten years in the wild but have survived up to 35 years in captivity.
REPRODUCTION: Snowy owls arrive in their breeding grounds in northern Alaska by mid-to-late May. The nest is located on a prominent, well-drained mound that provides a commanding view of the surrounding tundra area. The female scratches a hollow in the tundra to protect the eggs from spring winds and snowstorms. Some moss and feathers may be added to the simple nest. The male performs display flights and also displays on the ground. The male mounts the female and mating is quick. All during the nesting season the male maintains a nesting territory with loud hooting and will attack intruding owls, wolves and researchers. The number of eggs laid, ranging from four to sixteen, is dependent upon the abundance of prey.
When prey is less abundant the owls lay fewer eggs. The female lays an egg every two days, and she begins incubating as soon as the first egg is laid. During incubation the male provides all the prey for himself and the female. The eggs begin hatching after 33 days of incubation, in the order they were laid, at two-day intervals. The chicks are accordingly different sizes. If the food supply should become insufficient, the younger chicks in the snowy owl’s nest will be unable
to compete with their older siblings. The younger birds may starve or be eaten by their nest mates. The chicks that survive turn from downy white to a fluffy gray, and at ten days old turn nearly black. The chicks leave the nest when they are three to four weeks old, well before they can fly. The adults continue to feed the chicks. The young begin to fly (fledge) at about seven to eight weeks old, and they are completely independent at about nine weeks.
SOCIAL STRUCTURE: Outside of the breeding season, snowy owls usually are solitary.
DISTRIBUTION: Snowy owls breed in Alaska’s Arctic tundra, but during the winter they may be found as far south as California, Georgia and Texas.
MOVEMENTS AND MIGRATION: During the winter some snowy owls stay on the breeding grounds in the Arctic, while others migrate or wander as far south as the northern contiguous United States, with exceptional sightings recorded as far south as California, Georgia and Texas.
HABITAT: Snowy owls are synonymous with the open Arctic tundra. During the winter they may migrate south where they use open habitats, including prairies, marshes or shorelines, to find prey.
PREY: Snowy owls can capture and eat a variety of prey items including hare, ptarmigan and other birds, but lemmings are their primary prey. During the winter many snowy owls migrate to areas where prey is available and abundant, including meadow mice (voles), white-footed mice, deer mice, rats, pheasants, fish and carrion.
PREDATORS: Snowy owls are very alert and aggressive. They will attack intruders in their nesting territory. However, foxes and wolves do take the chicks. Jaegers, a predatory bird, can take the owls’ eggs and chicks. In some areas of Alaska, snowy owls are killed legally for human consumption. A popular technique used is to put a leg-hold trap on top of a post in the middle of the flat tundra. To gain a better hunting vantage point, the owl will land on the post and is trapped easily.
PREDATORY CHARACTERISTICS: Lemmings are snowy owls’ primary prey. Lemming populations are cyclic, and an abundant population can crash in less than a year. One population of lemmings may be very high while a neighboring population may be very sparsely populated. This makes for patchy prey, which predators try to locate. To adapt to the patchy prey, snowy owls are nomadic; they can breed in a different location every year. This allows the owls to nest wherever lemmings are most abundant.
CURRENT STATUS: Snowy owl populations are healthy in Alaska.
ECOLOGY/CONSERVATION: Snowy owls swallow small prey whole. Large prey, such as ptarmigan and hares, are torn apart. Any bones, teeth, feathers and fur eaten are non-digestible; they are compacted and then regurgitated as pellets. Since a snowy owl must eat up to a dozen mice each day, large accumulations of pellets can be located around perches. Biologists interested in owl and small mammal ecology can extract the bones from the pellets to determine the number and type of prey taken by the owls. Understanding the population dynamics of the prey helps scientists to understand the predator.
References:
Wright, Bruce A., 2011. Alaska Predators, Their Ecology and Conservation. Hancock House Publishing. 119 pages. http://www.hancockhouse.com/products/alapre.htm
Other species:
Pacific sleeper sharks in Alaska
Salmon sharks in Alaska
Great white sharks in Alaska
Bald Eagle
Gyrfalcon
Great Horned Owl
Black Bears
Brown Bears
Polar Bears
Orcas
Wolves
Wolverine