Snowy Owl

Snowy owls are one of the most recognizable species of owls in the world due to their white plumage and yellow eyes. It is enormous compared to other owls and is highly active during the day in stark contrast to their primarily nocturnal brethren, the other regular owl species.

While the population has been difficult to predict because of its unpredictable migratory patterns, it has been on the decline for some time.

Description

Size: Length:  21 to 28 in (54 to 71 cm) for females; 20.7 to 25.2 in (52.5 to 64 cm) for males.

Weight: 3.763 to 5.348 lb (1.707 to 2.426 kg) for females; 3.230 to 3.987 lb. (1.465 to 1.808 kg) for males.

Wingspan: 4 ft 9 in to 6 ft (146 to 183 cm) for females; 3 ft 10 in to 5 ft 5 in (116 to 165.6 cm) for males.

Body and Coloration:  They are white with dusky brown spots and bars. Their eyes are yellow, while their leg and feet remain covered in white feathers looking like fluffy slippers.

Male vs. Female

Sexual dimorphism is prominently noticed in them. Females appearing larger, have greater markings than males who are more whitish. In fact, with age the male snowy owls become wholly white, while the females retain their spotted appearance. The number of bars on the tail also vary, with three in the male, and between three and six in females.

Juveniles are generally darker and more heavily marked than adults. The male owlets replicate the females in their dark markings until maturity after which they look similar to the male owl.

Range and Distribution

Snowy owls are found throughout the Arctic regions. These owls breed in coastal Alaska, Canada, Greenland, northern Scandinavia, Russia, southern Novaya Zemlya, and northern Siberia.

In winter, they migrate south from the Arctic. One can find them in Canada and the northern United States, sporadically further south into the U.S., while in Eurasia they are seen in Iceland, the British Isles, northern Europe, central Russia, northern China, and Sakhalin.

Habitat

They live in various environments in tundra biomes, such as coastal dunes and other coastal spots, lakeshores, islands, meadows, moorlands, prairies, steppes, other extensive grasslands, and shrubby areas.

Diet

Carnivorous in nature, their main prey includes lemmings and mice. Other than that, they eat rabbits and different species of birds, depending on the season. In summer, the birds targeted include passerines, ptarmigans, and waterfowl, while in winter, buffleheads and grebes become prime targets.

Snowy owls play a major role in the tundra ecosystem by maintaining the rodent population, consuming around 1600 rodents on an annual basis.

Lifespan

On average, the snowy owls live for about 10 years in wild and 25-30 years in captivity.

Behavior

• Unlike most other owls, these birds are diurnal.
• These owls are solitary and territorial, defending their territories from each other by making noises and threatening postures. For instance, when annoyed or upon sensing a threat they react instantly by clapping their beak. The sound produced as a result of such action is thought to be brought about by the clicking of their tongue.
• While migratory, snowy owls do not follow any specific migration pattern. Their movement is mainly dependent on the availability of food, with the owls flying to places with a greater abundance of prey.
• They communicate and comprehend the environment around them by seeing, touching and even vocalizing through different sounds. The males mostly make the hooting sound typical in most owls. The other calls seen in both the sexes include “rick, rick, rick”, “kre kre kre”, mewing and hissing.
• The juvenile snowy owls emit a call that is soft but high pitched. Over time, this vocalization develops into a wheezy howl, before finally being able to utilize the same sounds as the adults.

Predators

They have very few natural predators, but the eggs are easier targets than the adults. Foxes and jaegers are among the few who prey on these birds.

Adaptations

• Snowy owls are round-bodied and covered with thick plumage, allowing effective body heat trapping.
• These owls have feathers covering their feet, giving them ample warmth especially when the weather gets chilly.
• They have keen senses, especially excellent hearing, and good eyesight.
• Since the flight feathers of the snowy owl are very soft, they tend to be silent while flying.

Mating and Reproduction

These owls are monogamous, forming breeding pairs in April or May. Males attract mates with a combination of aerial and ground displays. After a pair is formed, breeding takes place between May to September.

The nest is a combination of efforts from both parents, with the male scouting out a site with a view of the landscape and the female constructing a shallow bowl in the ground.

Life Cycle

Females lay 3-11 white eggs at intervals of 2 days. All the eggs hatch after 32-34 days of incubation. Both parents feed and protect them. Males bring food to the nest, where the mother dissects it into smaller pieces to feed the chicks. Chicks begin to leave the nest before flying, 14 to 26 days after hatching. The parents continue to provide for them for 5 to 7 weeks until they can hunt for themselves.

Conservation Status

The IUCN lists the snowy owl as “Vulnerable” or “VU”. Their population fell from 200,000 in 2013 to a very low 28,000 in 2018. Reasons for this sharp decline have been attributed to the drop in the numbers of their primary prey, lemmings, who, as a result of climate change, are now being targeted by multiple predators like Arctic foxes and seabirds.

Interesting Facts

• The Harry Potter books, and subsequent films, feature a female snowy owl named Hedwig.
• Snowy owls have several names:  arctic owl, ermine owl, ghost owl, great white owl, Scandinavian nightbird, snow owl, tundra ghost, and the white terror of the north.
• Symbolically speaking, a snowy owl represents the arrival of peace and happiness in short order.
• According to genetic testing, the evolution of the snowy owl has been dated back to 4 million years ago.