(tranquil music) ♪ (narrator) The Netherlands.

♪ (bird chirping) A country inextricably linked to its fresh water.

♪ And once home to an iconic mammal.

♪ Sadly, this elusive creature disappeared before the turn of the century.

But now the legend has returned to its former home.

♪ The otter.

(water splashing) The otter roams the Dutch waters again.

(water splashing) ♪ It's a symbol of the ecosystem's recovery.

♪ (seagulls calling) So why did the otter disappear, and what was the reason for its return?

♪ In the north lies Groningen, a vibrant city bustling with students.

Here, there's plenty to see and do.

(bell tolling) Especially if you know where to look.

(engine puttering) (metal cans crinkling) An otter.

One would only expect this rare and shy creature in undisturbed nature reserves, yet this one swims in the heart of a city.

(vibrant music) This carnivore effortlessly blends in with its environment despite being over a meter long.

Widely known as the Eurasian otter, it's the longest member of the weasel family in the Netherlands.

On occasion, it visits these urban canals to hunt for fish.

(water pouring) ♪ Although cautious, the otter doesn't go completely unnoticed.

(bird squawking) ♪ A last stopover to make before the city awakens.

♪ Its favored doormat, a perfect place to mark its territory.

♪ This city dweller has been asked to collect the otter's droppings, known as spraints.

DNA sampling helps build up a family tree of the otters in the Netherlands.

Genetic analysis confirms this individual is a male.

This shy and elusive creature completely disappeared from the Netherlands in 1988.

So how does it suddenly appear in a city?

(water lapping) Over the last century, otter populations declined all over Europe.

(soft, solemn music) This was due to excessive hunting as well as pollution from industrial and agricultural runoff.

♪ The chemicals poisoned the aquatic food chain at the top of which is the otter.

♪ With an ever-expanding network of roads, traffic accidents involving otters increased.

(car whirring by) ♪ And many got caught in fish traps.

♪ Loss of natural habitat added to its demise.

If plans to reintroduce otters were to work, its living spaces had to be restored.

(mellow music) Water pollution had to be drastically reduced, not only within the Netherlands but also across borders in cooperation with other European countries.

♪ After 14 years of intensive habitat restoration, the otter was reintroduced in the Netherlands.

♪ (tranquil music) ♪ (woman vocalizing) ♪ (birds chirping) ♪ The first otters were collected from Eastern European countries and were released in the Weerribben-Wieden National Park.

(bright music) This is Northwestern Europe's largest peat bog area.

♪ And the new cradle of the otter.

(scratching) ♪ Today, over a hundred live in this area, the highest concentration of otters in the Netherlands.

♪ (birds squawking) (croaking) It's summer, and male edible frogs compete vocally for females.

(soft jazz music) A nesting coot has its first hatchling, an adventurous type.

♪ The amorous amphibians embrace it with open arms, yet their hugs could be fatal.

(croaking) ♪ Dad intervenes when enough is enough.

♪ The eggs all hatch on the same day.

All of a sudden, there are lots of beaks to be fed.

♪ (frenetic music) Another uninvited guest shows up.

♪ (ominous music) No coot is a match for an otter.

(birds squawking) ♪ It clearly shows a close interest in the unsuspecting chick.

(birds squawking) It would make an easy snack.

♪ Birds are also on the otter's menu.

(water bubbling) ♪ But it's after more traditional prey.

(jazzy music) ♪ Ninety percent of an otter's diet consists of fish.

(munching) ♪ With its sensitive whiskers, it can detect its prey even in the murkiest of conditions.

♪ Recent findings suggest that it can even smell underwater.

♪ Today the otter adds a special to its menu.

♪ Invasive and plentiful North American crayfish.

♪ Breeding black-headed gulls don't trust this predator anywhere near them.

The whole colony sounds the alarm.

(squawking) Those feeling most threatened launch an attack.

(squawking) ♪ All that fuss for just a fish.

♪ (squawking) ♪ This smoke is an annual occurrence.

(fire crackling) After the reeds have been harvested, the waste is burnt.

Reed cutting is an ancient manual craft, and reed bed cultivation is essential to maintain this unique and characteristic landscape.

The craft is related to that of the thatchers.

Thatched roofs are still a traditional sight in this region.

Not all reed waste is burnt.

Sometimes it's left at the edge of the field.

This can attract otters looking for shelter.

In this case, under a tree at the water's edge.

(birds chirping) It looks an ideal place to have a nap.

Or even... have its young.

(elegant music) ♪ This pup is about two months old.

It's well-nourished on its mother's milk.

♪ (birds chirping) Sheltered inside, the presence of a curious pine marten doesn't concern the otters.

♪ (scratching) ♪ Soon, this youngster will be ready to join its mother on her trips and learn how to hunt for fish.

♪ Mother checks the surroundings for its next milestone.

♪ Its first swimming lesson.

There is only one way to take the plunge.

♪ At first, the pup is a bit reluctant, but who isn't at their first swimming lesson?

♪ (rustling) ♪ (water lapping) ♪ Seeing an otter that's being taught to swim may seem somewhat unusual.

♪ Even for a pine marten and her own young.

(rustling) (birds chirping) ♪ Its fluffy coat traps so much air, it keeps the pup afloat, and now it seems to get the hang of it.

♪ (bee buzzing) The Weerribben-Wieden National Park is home to many species, some of which are rare, like this large copper butterfly only found in these specific types of low peat areas.

(birds chirping) Other species are more abundant, like the stoat.

These youngsters still depend on their mother.

(birds chirping) Their dinner makes a run for it, but their mother keeps her eye on the prize.

She is a mouse specialist and makes good use of the concrete path.

She tracks the mouse down with her keen sense of smell and hearing.

(footsteps pattering) She will have to catch many more if she is to feed all of her youngsters.

The stoat is related to the otter, a miniature family member in overdrive.

(footsteps pattering) (birds chirping) Like the stoat, the otter has a high metabolism.

Each day, it needs to consume up to a fifth of its body weight.

(birds chirping) (water rippling) Otters are masters of stealth.

They keep a low profile, both when hiding... and when hunting.

(tense music) ♪ (chirping) ♪ This otter has not had its fill today.

♪ It wants its dessert.

♪ The female duck risks her life to distract the otter from her ducklings and drive it away.

(quacking) (dramatic music) ♪ But it's the season of plenty.

♪ There are other potential targets here.

♪ (squawking) ♪ (birds chirping) (grim music) (splashing) ♪ The juvenile coot's parents dare not intervene.

♪ They are no match for the otter.

♪ The juvenile never stood a chance.

♪ (traffic humming) The Weerribben-Wieden has some busy roads which are a major hazard for wildlife.

Otters usually have fixed routes in their territory which become visible when used frequently.

(birds chirping) (traffic rushing) This road has been fenced to guide otters into an underground tunnel.

A safe passage for wildlife.

It's simple and very efficient.

(engines whirring) (water splashing) (mellow music) ♪ (geese honking) ♪ (wings flapping) ♪ Six months have passed since its first swimming lesson.

♪ (water splashing) The youngster looks confident and no longer depends on its mother for food.

♪ Her cub is nearly full grown, and it's difficult to tell the pair apart.

♪ They spend less and less time together, and it won't be long until they go their separate ways.

♪ But for now, they still enjoy each other's company.

(water splashing) In boisterous play, the big youngster is now physically its mother's equal.

♪ (otters chirping) (water splashing) ♪ These two set the example of an animal species that plays well into adulthood.

(water splashing) ♪ This area has been their safe haven with plenty of food, but soon the youngster will leave to find a territory of its own, and from time to time, even adults may move into new areas.

A typical otter territory provides for many species, like these mute swans.

(chirping) After feeding, the cygnets are guided back to the safety of the nest.

(chirping) (birds honking) A new otter appears.

She is extremely cautious, and for a good reason.

(vibrant music) ♪ Three reasons, actually.

♪ She managed to teach all three pups how to swim.

Her next challenge is to keep the rabble together.

♪ (water splashing) ♪ They have discovered the joy of swimming and now step up their game.

♪ (water splashing) ♪ They live up to their name, "otter," which goes back to the old Germanic "utraz" and simply means "water animal."

♪ (chirping) There's always a dreamer that's lagging behind.

♪ But not forgotten.

♪ Otters are dedicated mothers, and she will keep a watchful eye on all three of them for the months to come.

(chirping) ♪ Barely a year after their reintroduction to the Weerribben-Wieden, otters started spreading north to the province of Friesland.

(mellow music) ♪ In the recent decades, Friesland authorities invested significantly in improving water quality.

As a result, fish stocks are recovering, and the otter is not the only resident to benefit.

♪ This fisherman has made a special adjustment to what's known as a fyke net.

A grid stops otters from entering the net where they would get trapped and drown.

(birds chirping) Now that the otter has returned, Friesland is also taking measures to safeguard it.

To protect the otters from traffic, otter-proof fences are constructed along roads in nature reserves.

♪ (traffic rushing) ♪ Roads that cross important wildlife pathways are fitted with underground tunnels.

♪ (whooshing) ♪ This highway got an even larger wildlife tunnel specifically designed for all sorts of aquatic and land animals to pass through.

♪ And the otter frequently leaves its footprints here.

♪ (geese honking) The otter has returned to one of Friesland's largest national parks, the Alde Feanen.

♪ (birds chirping) ♪ On the outskirts is a small village that has an annual race with Frisian icons: traditional peat sailboats.

(cranking) These cargo boats were used to transport the peat that was excavated up until the 19th century.

♪ Here is where the otter is welcomed back home.

♪ On their journeys, otters pass through many places.

(water rippling) ♪ But as they mostly travel at night, they are hardly ever seen.

(crank squealing) ♪ However, they may give their presence away.

Especially if there are lots of fish about.

(quirky music) ♪ Otters can quickly adapt to human environments, and what's more comfortable than a boathouse?

♪ It's an ideal place to mark your territory.

With no doormat on which to deposit a spraint, a deflated pool float will do just as well.

♪ (water splashing) Tragically, each year, up to a third of the Dutch otters die in traffic collisions.

(engine rumbling) This male otter, however, had a narrow escape.

Against all the odds, he recovered.

(gentle music) ♪ He is released to rejoin his brethren in the waterways.

♪ He gets a last piece of fish.

♪ And a little nudge towards freedom.

♪ (water rippling) ♪ (leaves rustling) (engine rumbling) To prevent more otters from attempting this dangerous crossing again, a road tunnel is installed.

(mellow music) ♪ The otter probably will have to get used to this new, life-saving route.

But soon, it'll see the light at the end of the tunnel.

♪ (car rushing by) ♪ (rustling) ♪ (water rippling) ♪ (birds chirping) The otter eventually reached the province and city of Groningen.

(peaceful music) To the south of the city lies a new marshland area known as the Onlanden.

♪ In 2008, pastures were turned back into wetlands.

♪ Former marshlands were restored and now teem with wildlife.

♪ (birds chirping) ♪ Five years later, the first otters arrived here, an extraordinary reward for all of the efforts to bring back nature.

(thunder rumbling) ♪ Wetlands are known to absorb a lot of water.

(rain falling) This was one of the main reasons to create this natural climate buffer next to Groningen.

(thunder rumbling) ♪ Two decades ago, the city experienced serious flooding.

(rain falling, splashing) The canals and water basins could barely cope with the heavy rainfall.

♪ To protect Groningen from future flooding, a drastic solution was needed.

♪ And so an area of 3,000 hectares was transformed into wetlands with large areas for water storage.

(water lapping) ♪ (water rippling) This male otter feels right at home.

Bridges are favorite spraint sites, and the flooding won't stop him from a vigorous inspection.

(water splashing) The scent will give him clues as to whether a potential mate or rival has entered his territory.

Further upstream, one of his favorite haunts remains dry.

(mellow jazz music) The otter leaves scent marks by rubbing his thick coat on any surface.

This also lets air into a layer of fine underfur which acts as insulation to protect him against the cold water.

At the same time, the scent marks announce his residency, a clear message to his rivals and, of course, the females.

♪ Suddenly, a female shows up.

♪ This could be his lucky night.

(rustling, water splashing) ♪ (shrieking) ♪ (birds chirping) (bright music) ♪ On the eastern border of the Onlanden lies a new waterway.

♪ It serves as another migration route for fish.

♪ A decade ago, during the digging of the canal, a new bridge and boat lock were built.

♪ (clanging) ♪ Each gate has a hatch for leveling the water inside the lock.

♪ And the fish found their way through as well.

♪ After sunset, things get quieter and some of the more cautious animals appear, like the roe deer.

♪ And a stone marten.

(playful music) ♪ And where there's fish, there's the otter.

♪ (bird squawking) ♪ A bridge was designed with a natural bank to safeguard animals from traffic.

(traffic humming) ♪ Here, otters find shelter, and it's the ideal place to scent-mark.

♪ Another spraint is always worth investigating.

♪ (splashing) A heron is having a good night.

♪ The vegetation next to the boat lock offers the otters concealment.

♪ (rustling) (traffic humming) More visitors.

(vibrant music) A whole family.

♪ Otters are very inquisitive and opportunistic.

♪ It won't take long before the otters will find their way into the lock.

♪ Any remaining fish will be in for an unpleasant surprise.

♪ The heron finds it all a bit fishy.

♪ (water splashing) A final visit to the bank.

If there's anything that attracts otters, it's spraints.

♪ (heron squawking) The heron calls it a night.

♪ (water rippling) (birds chirping) The new canal grants otters a safe passage to Lake Paterswoldsemeer, a perfect habitat from where they travel further east using their ancient routes again.

(peaceful music) ♪ Unfortunately, otters will also encounter this highway.

(traffic rushing) ♪ The concrete barrier which separates the lanes is impossible for otters to cross.

♪ Too many attempts result in casualties.

♪ In this case, it's a lactating female.

♪ This means her pups will be out there somewhere.

♪ Even though the chances are slim, a search party sets out to look for them.

♪ On a rare occasion, a pup is found and brought to an otter rescue center.

(squeaking) ♪ Raising such a small pup demands tender loving care.

♪ It will take time before it reaches adulthood and can be released.

(birds chirping) (otter squeaking) ♪ But its enthusiasm is a positive sign, and it's in good hands.

♪ (engine rumbling) To stop the otters in their attempts to cross the highway, a fence is built.

(hammering) It will guide otters to a safe underpass below the highway.

The underpass is wide enough for otters to swim through, and yet many otters don't feel safe.

They don't use it and continue to travel on land.

To solve the problem, walkways are attached to the walls.

(tranquil music) ♪ It's a simple and effective solution.

♪ (traffic rushing) Very soon, the highway will also have a concrete tunnel installed for larger animals.

♪ (grass rustling) ♪ (birds chirping) On the other side of the highway lies Drentsche Aa National Park, named after an ancient freshwater stream.

(water lapping) Broad-winged damselflies depend on flowing water with high oxygen levels.

(bright music) ♪ The stream is home to another aquatic mammal: the Eurasian beaver.

(birds chirping) In the water, it may look like an otter, but it's Europe's largest rodent, a vegetarian with a broad, paddle-like tail, and gnaws on trees which it uses to build dams and lodges.

♪ An otter's territory stretches far beyond that of a beaver.

It can cover up to tens of kilometers along the stream in search of fish.

♪ East of the Drentsche Aa National Park lies the realm of the white-tailed eagle: the Zuidlaardermeer area.

♪ It's a sanctuary to many bird species.

(chirping) (gentle music) Like this redshank.

(birds chirping) ♪ And the whiskered tern.

♪ It's a drinking water extraction area protected by strict regulations.

(squawking) (chirping) Many other species thrive here.

Stoats are common, as are black-necked grebes.

(water splashing) ♪ There is plenty of space for beavers to build their lodges.

♪ And now, otters thrive here too.

(water rippling) ♪ (munching) ♪ The natural habitat of Lake Zuidlaardermeer also appeals to people.

(birds chirping) In the quiet of the evening, new, wild neighbors come visiting.

(bright waltz music) ♪ (munching) ♪ (clattering) (squawking) (tranquil music) For now, the Dutch otter population has already reached its northern frontier.

They have spread as far as the coastal area, the Lauwersmeer.

♪ It's taken time, but the otter has made a successful comeback and is now spreading further across the Netherlands.

However, the Dutch otters are still isolated and vulnerable to inbreeding.

Genetic exchange with otters from Germany is essential.

The Dutch and German populations are edging closer but will need a helping hand to close the last gap of fragmented freshwater habitats.

The Eurasian otter has started to recolonize much of its former range across all of Europe.

♪ From the shores of Arctic Norway... ♪ ...to the rivers in Spain.

(water lapping) The vitality of these ecosystems is intertwined with the presence of this ambassador of the freshwater environment.

♪ (water splashing) ♪ (water bubbling) Winter is coming.

Animals that don't migrate or hibernate face a difficult time finding food and take it nice and slow to conserve energy.

(spirited music) Well, not everyone.

The stoat grew into its white coat and is ready for winter.

(ice skates clanking) ♪ And there are many more that welcome the cold.

The Dutch are well known for their passion for ice.

♪ (ice skates scraping) The Weerribben-Wieden is transformed into an idyllic postcard.

♪ The pine marten inspects its icy territory while the young mute swans have to cope with a slippery landing strip.

♪ The otter is in its element.

♪ The mother of the three pups is still in her territory.

As long as not all water freezes over, she will still be able to find food here.

♪ Her pups are now less dependent, but they should still be around somewhere.

♪ Not all pups survive their first year, but these have made it.

♪ It's their first winter.

Both are in good condition and can withstand the bitter cold covered in their dense fur.

♪ The slippery ice doesn't seem to bother them at all.

♪ These two actually seem to enjoy the icy conditions.

♪ But what about the third pup?

♪ (ice crunching) There it is!

♪ It's persistent, and like its siblings, it's surviving well.

♪ (squawking) (wind howling) (ice crackling) (soft footsteps) (gentle music) ♪ The city of Groningen can expect its nightly visitor once more.

♪ When the temperature drops below zero degrees, its footprints lead into the city.

♪ It's believed that it follows the fish that now migrate into these relatively warmer waters.

♪ (wheels rattling) ♪ It's a miraculous site: an otter in the heart of a city.

(water splashing) ♪ The otter vanished from the Netherlands because of human activity.

♪ And yet, it is thanks to humans that it returned.

♪ The otter symbolizes hope for the natural world, and its presence rewards our efforts to protect it.

♪ (tranquil music) (woman vocalizing) Ahead lies a long and difficult path to restore our freshwater environments.

♪ But now we have a legend to guide us.

♪ All we have to do is follow its lead.

♪