Somewhere high up in the north, in the vast and barren terrains
of the tundra lives a very mysterious animal, often symbolic of wisdom, historically revered as a medium
between the worlds. The snowy owl. Best known by fans of Harry Potter. In some years, it undertakes the long journey
westwards to Europe, sometimes to Germany. Why does it exert itself to such extremes? Lemmings and snowy owls are entwined. Their relationship
exists for thousands of years, most for the lemming and with its death. For the owl, it is essential. The prey is not for the hunter. His mate is waiting. The pair have four offspring to rear. The father
has to leave again straight away. The mother stays to feed
the three-week-old chicks. They have to gain weight quickly because autumn
will begin in three months' time. In the land of the snowy owl, the sun won't set for many weeks,
and thus, quite untypically for owls, it hunts in the daylight. Its eyes are accustomed to it. Nothing escapes its attention. Watching and waiting… That is its strategy, but not for waterfowls. They're not so well suited for the chicks. The owl is waiting
for the lemming above all else. It's taking too long for the female. The chicks need
at least four rodents per day. Not a problem in good lemming years when the male
can provide one after the other. Then the owls can manage
to raise up to 11 offspring. However, right now,
there are few to be found. That's why the family is so small. When food is in short supply,
owls lay fewer eggs. Nevertheless, it's still not enough
for the little ones. Around every four years, there is an explosion
in the lemming numbers. At least, that's how it's been until now. Now such a boom time
for lemmings is long overdue. What is it that has disrupted this cycle? If there is too little food, it is the last born,
and, therefore, the smallest that will pay the price
for its development. Its chances to compete for its share
against the larger chicks will be ever more remote. The male is out for increasingly
prolonged amounts of time to find prey. It's vital that the mother manages
to protect her young against the icy winds. In a short time, the temperature
will drop to near the freezing point. The mother deepens the hollow
of the nest for protection while the father
searches in vain for lemmings. The family is starving. It's as if the lemmings
have been swallowed up by the ground. The mother has nothing more
to offer the pleas of her nestling. She seems to have run out of ideas
as to how to help her dying chick. The adults can deal
with far lower temperatures. But for the smallest
in these circumstances, there is no chance. The male has no time to lose. He has to make sure at least
that the other chicks survive. The owl will feed the dead chick
to the other chicks. Every form of nutrition is imperative as long as the male
continues to have problems. The fortune of the family is uncertain. One thing is for certain, though, an increase in lemming numbers
this summer has not materialized. The chicks have to manage
to achieve a weight of at least two kilos within the next three weeks. If not, they will not survive the winter. The fog hardly clears at all. Already in the middle of August, it is autumn. The geese begin their escape to the south. Snowy owls, however,
are not migratory birds. They remain where they are. A little later
and the tundra is covered with snow much earlier than expected. The landscape
is in the grip of temperatures that sink to -40 degrees Celsius. It is only they who can adapt
that will survive. Even the feet, velvety soles
are covered with feathers, as is the beak. It's the same with the Arctic fox, white as camouflage and warmly covered with fur,
even under the paws. Owls and foxes share a similar fate
in that they both hunt lemmings. For both of them,
it is now essential that they find some, as the temperature sinks. The owl now has a difficult decision. Should it try and bear it out here
and continue searching like the fox, or is the snow too deep and hard and it will be under threat
of diminishing fat reserves? The fox has no choice in the matter, but the snowy owl does. It doesn't always migrate
like other birds, but will travel
if the conditions are too extreme. It leaves the Siberian desert of ice
behind and travels westwards. Traveling at up to 85 kilometers per hour,
it can cover large areas of Russia. Ahead lay the fells of North Scandinavia, 2,500 kilometers away
from its breeding grounds. Here, the wind clears
the tops of the mountains, increasing the owl's chances
of finding some lemmings. The open terrain is an invitation to rest. The owl needs a clear view
for its hunting. The stranger's presence
doesn't go unnoticed. However, the reindeers
soon returned their attention to the arduous process
of uncovering moss and lichen. The secret as to why they don't suffer
from hypothermia lies with their large snouts. The icy air warms up
through the long nasal passage and the heat is retained
when they breathe out. Their wide hooves act like snowshoes and prevent the animal
from sinking too deeply into the snow. However, the true master
of walking on snow is the alpine rabbit. With its white fur and smaller ears, it's perfectly suited
to the sub-polar environment. This elegant snowshoe sprinter
would be the perfect catch for the owl, if only it wasn't so very quick. What else is on offer? Snow grouse. They've spent the night
in a well-insulated snow chamber, a bit like an igloo. Hunger has forced them
to leave their cover together. Many eyes
are their best protection to survive. The owl observes them attentively. However, its attention
doesn't go unnoticed. No luck again. Finally, a mountain lemming, a little more bespeckled
than its brown cousin in Siberia, but just as delicious. It's collecting grasses and lichen
to stock up its pantry under the snow. That's where it spends
most of its time in the winter, well protected and hard to find. The snowy owl must use its chance. The lemming is watchful. Walking on its snowshoes,
it stalks the lemming, trusting in its camouflage
and the element of surprise. However, its cover has been blown. The lemming is confoundedly fast. Another attempt is for now
out of the question. Heavy snowfall impedes visibility. This is the beginning of a very hard time, even for the reindeer
who are so well used to the cold. They only have the chance
to remain and starve or to make the energy-sapping journey
through the deep snow to search out new pastures
for their meager diet. The lemming
has absolutely no problem with the snow. Quite the opposite, it's an ally, foraging, stocking up, eating, and raising its young
up to six times throughout the winter. It manages all that buried under the snow
and rarely ventures out. If there's a new covering of snow,
it offers the perfect protection against the cold and enemies. For the owl, it's a tragedy because it makes
the rodents much harder to find. It's only in those places
where the wind blows a clearing that it has a chance. The first attempt, the rodent, hidden in its labyrinth,
has a clear advantage. It's no stranger to protecting himself. Deep snow hunting,
it seems, is not for the owl. The reindeer leave
the inhospitable terrain. The snowy owl is also forced to move on. Indeed, the perennial aviator
will cover the circumference of the pole throughout the winter
in search of nourishment. If it doesn't meet with success,
the journey will be very risky. Will its undernourished energy reserves last long enough to reach
the south where it can hunt again? The energy-sapping flight is grueling. A short catch-in-between
could be much needed, but here also, the snow is far too deep. The great grey owl
shows how to be a good, deep snow hunter. It seeks out the mice from above
and makes its approach silently gliding before plunging the last meters
with full force, landing deep in the snow. Although only around two kilos in weight, it manages
to pin-pointedly capture its prey up to 40 centimeters under the snow. The competition lurks in the background. The supply of mice is small,
but the hunger is big. Every little bit counts in the winter. The Hunter has already swallowed
his well-earned rewards but it takes a while
for his competition to notice. With such tough competition around,
the snowy owl has no chance. It has to leave the Taiga forests behind. It can't hunt between trees. Open spaces
with a milder climate are the aim but its destination
is still as yet a long journey away. After a further 500 kilometers, it has still not crossed
the undesirable coniferous forest. Exhausted, it stops for a rest. As dusk approaches, the forest of the trolls
is suddenly awake. Millions of bramblings are heading south and are looking
for a place to rest for the night. A very real spirit of the forest
makes an entrance. The snowy owl must heed him attentively. He could be very dangerous. A wolverine. This giant marten can cover up to 45 kilometers in a night
in its relentless search for food. In the winter,
it'll eat anything it can find. Nothing escapes
its highly tuned sense of smell. A leftover carcass
distracts its attention. However, its attention
doesn't go unnoticed. The lynx is not impressed when it discovers someone
hunting on its terrain. The wolverine thinks better of it
and ambles on. The lynx is already full and is looking for a quiet branch
to settle down for the night. Taken, the lynx decides not to trouble itself
with an argumentative owl. Long and cold hours lay ahead of the owl. It's a night as if made
for myths and fairy tales. Where the northern lights dance
like fluorescent ghosts in the night sky, perhaps the myths
about the ambassadors to the other side stemmed from such nights as this. They are the stuff
of JK Rowling's creation Hedwig, the messenger owl
in Harry Potter's Magical World. A little more factually seen, they are the result
of a natural phenomenon. The solar winds, highly charged particles
collide with the Earth's atmosphere, triggering the atoms
into this majestic play of light. As the sun rises, this intriguing spectacle
is totally absorbed by the daylight. The starting gun for the black grouse
who come to the same place year after year to perform
their communal courtship rituals. Every male occupies
his own small personal territory and sets out to impress the competition, not only acoustically, but dramatically as well. The red wattles above the eyes
swell up for the annual occasion. The oldest and the highest ranking
occupy the center of the courting arena. A younger member of the group
is staking his challenge to the helm. A duel, it's called. Like two swordsmen, the birds set at each other
with their powerful beaks. They attempt
to hit each other on the red wattles. A direct hit. The younger has managed
to grab hold of the older. For this, it will have to endure
some powerful retaliatory swipes with the wings. With this duel,
both young and old can be disciplined. It will only be the winner
who is allowed to mate with the females. It seems grouse
won't be on the menu for breakfast. It forces the owl
to continue its journey southwards and to leave
the Scandinavian Taiga behind. It has to finally get
to suitable hunting grounds. By and by, deciduous trees such as birch
are mixed into the palette of the forest and the days grow longer and warmer. After another ten days' flight, it finally reaches the North Sea
on the south coast of Scandinavia. However, instead of finding
a large stretch of open water with resting seabirds beneath,
there is nothing else but an icy desert. This year, the Arctic temperatures have even gripped
the expanses of moderate climes. Across Denmark, the land of the Vikings,
the picture remains the same. Five thousand kilometers
now lay behind it. It's only as it reaches the Wadden Sea
around the German North Sea islands that things look better. In between the tidal waves, swim schools of flounders
without the protection of ice. Has it finally reached its goal? A young, snowy owl
has arrived two weeks earlier. Although less experienced, the younger birds intuitively set off
for the journey earlier. It's found a fully set table
on Germany's North Sea coast. Seabirds as far as the eye can see. From mallards to sheldrakes, all fighting for a place as the evening sets in
on the interior freshwater lakes behind the coast. Here, they're best protected overnight
against such nocturnal predators like the marten or the fox. By the next morning, most of them have survived
the uncomfortable cold of the night, and in ice-cold water
with bare feet at that. How do those water birds
manage not to freeze? Astonishingly enough,
they lose very little heat on the ice. They are equipped with a perfect
heat exchange system in their legs. Warm blood flows downwards
and the cold blood upwards. At an abundantly flowing bottleneck, the warm blood exchanges
with the cold blood, which travels back into the body, saving energy
by keeping one's feet cold, in principle. Without such an ingenious
heat recovery system, the smaller birds above all else
would quickly freeze. Despite this impressive wonder of nature, the birds are constantly under pressure
throughout the winter not to starve. The grey heron normally hunts fish. However, when the waters are frozen,
a plan B is needed. It keeps its eyes on the shelducks, fish hunters like itself. Perhaps he can wrangle something
out of them. The smew comes from far away, from Siberia, like the snowy owl,
which is watching on as ever. The owl waits. Perhaps one of the many birds
won't be paying attention. This solitary duck, perhaps. The lemming hunter
transforms into a bird hunter. The tactic remains the same. It will take what is easiest to overpower. However, hunting birds
is not such an easy undertaking. What makes it even more difficult
is that the birds warn each other. The snowy owl has to stay hungry for now. A shelduck is having
a bit more luck with its catch. However, that is only short-lived. Here, thievery is the order of the day. Thieves are bound everywhere. No movement escapes attention. Albeit when two are having a dispute, the third one reaps the benefits. The herons haven't given up yet. The gull doesn't even
get a chance to swallow. So much commotion all over one fish. Nothing illustrates
the necessity of the birds more. It's not absolutely the strongest
that perseveres here, but more they with the most cunning. The clever gull
swallows the fish straight away. Should the waters freeze completely, it will come down
to a basic fight for survival. A fight has flared up over the last fish
among the herrings. No rule is barred in the bird's efforts
to stop the other from swallowing. They who run out
of steam to struggle will die. During the harder winters,
around 50% of the herons will starve. Only the most resourceful
of them will survive. Some animals decide
not to trouble themselves at all with the hardships of winter. Hidden away in the hollow of a tree, a garden dormouse takes its leave
of the inconveniently cold season. Its body temperature
has sunk to just above freezing and its metabolism
has reduced itself to a minimum. Its heart beats only slightly per minute. A whole range of animals disappear
from the picture altogether during the winter months, and emaciate themselves
from their fat reserves while sleeping. Tree hollows are mostly favored
by the household and the edible dormice. The hedgehog, on the other hand, likes to bury itself
under dried-out foliage and grass. Hunters like the snowy owl have no chance
to find them in their hideaways. Many other animals
simply have to bear it out. With its bushes filled with berries
and its apple trees, the coastal region in the north of Germany
serves as a gigantic fridge for the birds. Fieldfares and the common blackbirds
absolutely love the rich frozen fare. Apples contain large amounts
of sweet fructose and are good sources of energy. Every apple harvested
could be a lifesaver. Even the newcomers arriving from the taiga
enjoy the benefits of the fruit. The waxwings are not the only guests who have made
the arduous journey from the North. The older snowy owl arrives on the scene. Famished after a flight
of nearly 5,000 kilometers, it is in urgent need of nutrition. However, the partridges are all too aware. Finally, there is hope for the owl again. On the relatively open plains,
chances are much better for hunting. A hundred years ago, the snowy owl's numbers
were much larger in Central Europe. Today, it is extremely rare. Some even come as stowaways. During a storm in 2014, five American owls
found shelter on a ship bound for Europe. From board, they flew over the Netherlands
and back home again. A modern winter's fairy tale. Such a comfortable journey
wasn't had by this owl. Added to that, it now faces competition… Fox, and ermine. All are chasing the same thing… The mouse. The ermine looks
as if it could have a plan. What could be the reason
for this sprightly little romp? The fox is taking its time. It's monitoring
for slight sounds beneath the snow. The performance was not without its merit. The ermine aims to shock the mouse
and try to scare it out of its safe haven… and it works. The victory is short-lived. Try again. Very fortunate for the patient guest. Ermines and foxes hunt mice
as their primary source of prey. They are dependent on it
for their numbers. As ever, the snowy owl watches on. The ermine has to keep
a close eye on the owl. Sometimes owls just can't resist
their kleptomaniac urges. A younger snowy owl enters the scene. The feathers of the young and the females
are covered with brown speckles. Perhaps it's one of her own chicks. The ermine has had enough for the day. End of the show. Not all are such rare guests
as the snowy owl, though. Whooper swans rest
in their thousands in the north of Germany before undertaking their return journey
to the Siberian taiga. Throughout February,
the sun's rays increase and the spirit of departure
reverberates across the lake. Getting 11 kilos off the surface
is a job in itself. For the young snowy owl,
their departure is the signal to return. It takes the route along the Baltic coast. It's following the route
of the other birds. The best hunting chances
are wherever they choose to take a break. Finally comes the thaw. Without snow and ice,
everything is much easier. Hunting strategies suddenly change. This time the owl
wants the ducks to see it, and it glides directly toward them,
forcing them to dive. It hovers above with patience. The first to come up for air dies. Today, it is catered for. Around 50,000 barnacle geese now set off
for their Arctic breeding grounds. The snowy owl also has to endure
this last grueling stage, over 4,000 kilometers
passing via the Arctic Circle. An unusually hard northern winter
has led the owl to Europe. However, such years
will become less common. Who knows if it will find its way
to these shores again? Climate change
will also have an effect on its life. The cyclical lemming outbreak
in many regions of the tundra has dropped drastically
over the last 20 years. A possible reason
is the rise in temperature in the Arctic. At present, it is around
one-degree centigrade per decade. The winters become shorter
and more clement. As a result, the lemmings lose their deep
and protective layer of snow early in the year. The large-scale outbreak
of the last generations has been dramatically reduced. The gradual thaw of the Arctic
will have pronounced effects on many of the specialized
inhabitants of the Arctic, and yet the exact ecological consequences
remain largely unknown. The snowy owl has returned
just in time for the Arctic spring. The Lapland Longspur
is at the height of its mating season. When the cotton heads are formed, the first half of the six-week
Arctic summer has already passed. The birds have to hurry
in rearing their new offspring. The growing season
to the advantage of many chicks will increase due to climate change. Even the geese which feed on grass
will be a beneficiary. The snowy owls
have yet again a small family this year. Now as before, they're dependent
on their supply of lemmings. How the diminishing numbers
will have an effect over the long term remains to be seen. On the other hand, perhaps they won't be forced
to fly so far south as a result of the milder Arctic winter. One thing remains clear for snowy owls, to survive in the magical world of winter,
one needs particular qualities: intelligence, a sense of adventure,
and immense powers of endurance.
