Enchanted by OwlsPhotographer Sven Začek was stalking moose in a frozen Estonian forest when he saw his first Ural owl. Looking into her black eyes was the beginning of an obsession which has lasted for nearly two decades.

Despite being a forest-dwelling bird, the Ural owl sometimes hunts in open habitats, where prey such as voles and other rodents abound. Late in winter, the females might become more visible, because they have to build enough fat reserves for nesting, when they can lose up to a third of their bodyweight.

Snow can conceal prey like voles, but such protection is no match for the owls’ hunting adaptations. Heightened vision allows them to spot movement, while their satellite-dish faces channel sounds to their supersensitive ears.

A female ural owl preens her feathers and talons. Wintertime is hard at this latitude. The owls concentrate on saving energy, hunting when conditions allow and taking care of their plumage.

[Top] In winter, a Ural owl feeds on a vole.[Bottom] An early spring has resulted in a caught frog.

The Ural owl lives in mature deciduous and mixed forests in northern Europe from Scandinavia to Japan and is named for the mountains that cross its range.

In larger forest areas, the owls make do with a few roads and ditches to break up the forest landscape, and provide hunting grounds.

In Estonia, Ural owls prefer old growth forests that are surrounded by uncultivated open fields or smaller clear-cut areas.

The Ural owl is nocturnal, with peaks of activity at dawn and dusk. It roosts during the day in the cover of trees.

ABOVEA female Ural owl flies over her nest on a clear, starry night. The male and female look for a suitable nest site together, where the female can lay her eggs.

LEFTA male courts a female with a gift of food. Males claim territories by calling from different perches, and during courtship may be heard dueting with their mates. The mating rituals of the owls last for a long time. Anything from two weeks to a month is a reasonable period for choosing a mate for a new breeding season. Once a nest has been found, the female stops feeding herself and lets the male do the work. She is testing both his hunting capabilities and the abundance of food. These factors ultimately determine how many eggs she will lay.

Nest sites include trees cavities, hollow trunks and rock depressions. Ural owls have also been known to use the abandoned stick nests of larger birds as well as squirrel dreys.

Incubation duties fall solely on the female. Depending on food supply, she may lay between 1 and 7 eggs, which will be incubated for about a month before they hatch.

ABOVE During an extremely hot spring, when tempertaures rose to +30C and stayed there for almost two weeks, a female Ural owl nesting out in the open was forced to abandon her egg.

BELOW An aspen tree, which contained the nest of a Ural owl, was felled by a storm,

TOP ROWEach male is different. Some only feed their mates in complete darkness, others have more flexible schedules.

RIGHTDuring nesting the female completely relies on the male to provide food. Initially, there is only one mouth to feed, but later the female will need enough for the nestlings too.

Ural Owls are spread all over Estonia, except for the islands. They prefer diverse habitats in bigger woodlands with a mix of old forests and clearcuts.

A female makes a rare trip away from the nest, landing on branch to be fed by her mate.The Ural owl’s main prey are voles, shrews, mice and rats. surplus food is stored at the nest or in nearby caches.

ABOVEThe feathers on a Ural owl’s wings have serrated edges; an adaptation which minimises noise while flying, helping the birds to sneak up on their prey.

LEFTLike all birds of prey, the Ural owl has eyes that face forward, giving it excellent binocular vision. The eyes are tube-shaped, which means the owl can’t roll them to look around. Instead, it has to turn its entire head. Ural owls are also extremely long-sighted. They rely on the sensitive bristles around their beak to detect objects at close range.

Photographer Sven Začek used a double exposure to photograph this Ural owl pair. The female is in the foreground, sitting on the nest, while the male perches in the background, ever vigilant.

After sitting on the nest for a full month with only a few minutes of stretching time per day, the females’ eggs begin to hatch, welcoming new life into the nest.

A mother feeds her young with a pellet she has regurgitated.Begging for food at the nest entrance.

An owlet takes a nap near the tail of a future meal.

A female hides an owlet underneath her wing. Ural owl mothers are extremely protective of their young. Females can strike a human intruder with considerable force. Males play only a minor role in nest defence.

Only during colder nights and rainy days will the female resume the sitting position to keep the nestlings warm.Around two weeks after the nestlings have hatched the female is finally able to leave the nest. She will usually perch on a nearby branch and keep a close eye on the nestlings.

Chick rearing depletes a female’s fat reserves. But once the young are old enough to be left alone, she can make short hunting trips.

A mother owl preens her feathers during a break from nesting duties. Female body condition is an important determinant of reproductive success.

The chicks leave the nest when they are about a month old. They are cared for and fed by both parents for about two months after leaving the nest.

This owlet was attempting to scale an aspen tree, but even with its formidable beak and talons, the bark was too slippery for it get a decent grip. After trying for half an hour, it gave up and went in search of another tree to climb.

The owlets jump to the ground before they can fly, and that makes them vulnerable. In order to avoid ground predators, they have to climb trees.

The owlet found itself upside down, gripping the branch with its talons. It took 15 minutes and a lot of wing flapping before the young owl was facing the right way again.

A female preens her owlet’s head while the youngster relieves itself. Afterwards, the adult bird took off and the branch bounced, causing the owlet to lose its balance.

Due in part to its large range, the Ural owl is still common. However, population decreases have occurred in areas where hollow or broken trees have been removed.

Nestlings can fly fairly well at about 45 days, and reach sexual maturity before they are 1 year old. This image was taken at dusk, when the birds become more active. This owlet, however, is still too young to hunt for itself.

Photographer Sven Zacek was photographing roe deer in open fields when this Ural owl landed on his car. In snowy conditions, the owls hunt out in the open. With no trees nearby to help it scope out the land, the owl opted to use the car as a temporary perch.

Sven Zacek is a freelance photographer who shoots a wide range of subject matter but is particularly drawn to wildlife and land-scapes. Since becoming a photographer in 2005, he has published seven books, written hundreds of articles, and given hundreds of workshops. He is the Editor-in-Chief and publisher of the Estonian nature photography magazine LoFo.

Contact:

timaldred@naturepl.com

+44 (0)117 911 4675