Snowy Owl

## Description

The Snowy owl (Bubo scandiacus) is a large, white owl of the true owl family. It has a number of unique adaptations to its habitat and lifestyle, which are quite distinct from other extant owls. Most owls sleep during the day and hunt at night, but the Snowy owl is often active during the day, especially in the summertime. It is a nomadic bird, rarely breeding at the same locations or with the same mates on an annual basis and often not breeding at all if the prey is unavailable. Snowy owls can wander almost anywhere close to the Arctic, sometimes unpredictably irrupting to the south in large numbers.

## Appearance

Snowy owls are mostly white. They are purer white than predatory mammals like Polar bears and Arctic foxes. Often when seen in the field, these owls can resemble a pale rock or a lump of snow on the ground. It usually appears to lack ear tufts but very short (and probably vestigial) tufts can be erected in some situations, perhaps most frequently by the female when she is sitting on the nest. The ear tufts measure about 20 to 25 mm (0.79 to 0.98 in) and consist of about 10 small feathers. Snowy owls have bright yellow eyes. Females are almost invariably more duskily patterned than like-age males. In mature males, the upper parts are plain white with usually a few dark spots on the miniature ear-tufts, about the head, and the tips of some primaries and secondaries whilst the underside is often pure white. The adult female is usually considerably more spotted and often slightly barred with dark brown on the crown and the underparts. Her flight and tail feathers are faintly barred brown while the underparts are white in base color with brown spotting and barring on the flanks and upper breast. In confusingly plumaged Snowy owls, the sex can be determined by the shape of wing markings, which manifest as bars more so in females and spots in males. However, the very darkest males and the lightest females are nearly indistinguishable by plumage.

## Distribution

Snowy owls are native to Arctic regions in North America and Eurasia. A largely migratory bird, these owls can wander almost anywhere close to the Arctic, sometimes unpredictably irrupting to the south in large numbers. During the winter, many Snowy owls leave the dark Arctic to migrate to regions further south. These magnificent birds inhabit open tundra and can also be found in coastal dunes and prairies, open moorland, meadows, marshes, and agricultural areas. Not infrequently, they will also use areas of varied coastal habitat, often tidal flats, as a breeding site. Often SNowy owls prefer areas with some rising elevation such as hummocks, knolls, ridges, bluffs, and rocky outcrops.

## Behavior

Most owls sleep during the day and hunt at night, but Snowy owls are active during the day, especially in the summertime. Outside of the breeding season, these birds lead a solitary life. They are often seen resting on the ground or on mounds, rocks, fences, and buildings. Snowy owls are opportunistic hunters and a variety of prey species may vary considerably, especially in winter. Most of their hunting is done in the "sit and wait" style; prey may be captured on the ground or in the air, or fish may be snatched off the surface of bodies of water using their sharp talons. Snowy owls, like other carnivorous birds, swallow their small prey whole. These birds are shy and generally silent. Their calls are varied, but the alarm call is a barking, almost quacking krek-krek; the female also has a softer mewling pyee-pyee or prek-prek. The song is a deep repeated gahw. They may also clap their beak when threatened or disturbed. While called clapping, it is believed this sound may actually be a clicking of the tongue, not the beak.

## Diet

Snowy owls are carnivores. They feed on a wide variety of small mammals such as lemmings, meadow voles and deer mice, but will also take advantage of larger prey. Some of the larger mammal prey includes hares, muskrats, marmots, squirrels, rabbits, raccoons, prairie dogs, rats, moles, and entrapped furbearers. Birds preyed upon include ptarmigan, ducks, geese, shorebirds, pheasants, grouse, coots, grebes, gulls, songbirds, and even other raptors, including other owl species.

## Reproduction

Snowy owls are generally monogamous and often mate for life; however, polygynous behavior may occur occasionally and males may mate with two females that may nest about a kilometer apart. The breeding season is usually from May to June. During this time the male performs courtship display to attract a female or to strengthen an existing pair bond. Snowy owls nest on the ground, building a scrape on top of a mound or boulder. They choose a site with good visibility, such as the top of a mound with ready access to hunting areas and a lack of snow. Gravel bars and abandoned eagle nests may also be used. The female scrapes a small hollow before laying the eggs. Depending on the amount of prey available, clutch size ranges from 3 to 11 eggs, which are laid singly, approximately every other day over the course of several days. Hatching takes place approximately 5 weeks after laying, and the pure white helpless owlets are cared for by both parents. Both the male and the female defend the nest and their young from predators, sometimes by distraction displays. Owlets begin to leave the nest and crawl around the area 14-26 days after hatching and fledge 7 to 8 weeks later. Reproductive maturity is usually reached at 2 or 3 years of age.

## Population

### Threats

Snowy owls are not considered endangered however, human activities pose the main threat to these beautiful birds. Among these are collisions with power lines, wire fences, and vehicles. Snowy owls also suffer from illegal hunting and are also often caught in fishing equipment.

### Number

According to the IUCN Red List, the total Snowy owl population size is around 28,000 mature individuals. The European population consists of 700-2,300 pairs, which equates to 1,400-4,600 mature individuals. Overall, currently, Snowy owls are classified as Least Concern (LC) on the IUCN Red List but their numbers today are decreasing.

### Ecological niche

Snowy owls play an important role in their ecosystem; they control populations of a wide range of small rodents which is especially useful in agricultural regions.

## Fun Facts

The Snowy owl is the official bird of Quebec, Canada.

Snowy owls are one of the heaviest among all owls due to their abundant coat.

To meet its daily food requirement the Snowy owl must capture roughly 7 to 12 mice per day.

As Snowy owls rely primarily on lemmings in their diet they can eat more than 1,600 of these rodents per year.

Snowy owls have such an acute hearing that they are able to hear prey moving under the snow.

The feathers of Snowy owls are very soft making their flight silent. It is very helpful when hunting because these birds are able to approach prey without being noticed.