Photographer 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.

We explore his extensive portfolio examining the life history and behaviours of this charismatic and enchanting owl species.

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. Despite being a primarily forest-dwelling bird, the Ural owl sometimes hunts in open habitats, where prey such as voles and other rodents abound. In late winter the females are observed more often, because they are active building up enough fat reserves for nesting, when they can lose up to a third of their body weight.

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 super-sensitive ears. Ural owls are dietary generalists, although their diet mainly consists of small rodents such as voles, particularly in winter. They have been observed eating frogs in spring.

In Estonia, Ural owls prefer old growth forests that are surrounded by uncultivated open fields or smaller clear-cut areas. In larger forest areas, the owls make do with a few roads and ditches to break up the forest landscape, and provide hunting grounds. The Ural owl is nocturnal, with peaks of activity at dawn and dusk. It roosts during the day in the cover of trees.

Finding a Mate

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. The male and female look for a suitable nest site together, where the female can lay her eggs. 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.

Nesting

Nest sites include tree 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.

It’s not always plain sailing – storms and unseasonable weather can cause serious problems.  During an extremely hot spring, when temperatures rose to over 30°C and stayed there for almost two weeks, a female Ural owl nesting out in the open was forced to abandon her egg (above left). An aspen tree, which contained the nest of a Ural owl, was felled by a storm (above right).

Teamwork

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

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. 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.

Acrobatics

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. 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. 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.

Climbing Practice

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. 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.

Nestlings can fly fairly well at about 45 days, and reach sexual maturity before they are 1 year old. 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.

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Sven Začek is a freelance photographer who shoots a wide range of subject matter but is particularly drawn to wildlife and landscapes. 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.

You can view a full gallery of Sven’s Ural owl images here.

The full pdf can be found here.